Merge branch 'master' into all-contributors/add-MSaifAsif

# Conflicts: # .all-contributorsrc # README.md
docs: add kanwarpreet25 as a contributor (#1405 )
2020-07-29 18:25:59 +03:00 · 2020-07-29 18:25:03 +03:00 · 2020-07-29 18:23:23 +03:00 · 2020-07-29 18:21:41 +03:00 · 2020-07-29 18:19:53 +03:00 · 2020-07-29 18:18:07 +03:00
2047 changed files with 73562 additions and 20134 deletions
--- a/.all-contributorsrc
+++ b/.all-contributorsrc
@ -0,0 +1,580 @@
+{
+  "files": [
+    "README.md"
+  ],
+  "imageSize": 100,
+  "commit": false,
+  "contributors": [
+    {
+      "login": "iluwatar",
+      "name": "Ilkka Seppälä",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/582346?v=4",
+      "profile": "https://github.com/iluwatar",
+      "contributions": [
+        "projectManagement",
+        "maintenance",
+        "content"
+      ]
+    },
+    {
+      "login": "amit1307",
+      "name": "amit1307",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/23420222?v=4",
+      "profile": "https://github.com/amit1307",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
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+      "name": "Narendra Pathai",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/1792515?v=4",
+      "profile": "https://github.com/npathai",
+      "contributions": [
+        "code",
+        "ideas",
+        "review"
+      ]
+    },
+    {
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+      "name": "Jeroen Meulemeester",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/1545460?v=4",
+      "profile": "https://github.com/fluxw42",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
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+      "name": "Joseph McCarthy",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/4526195?v=4",
+      "profile": "http://www.joemccarthy.co.uk",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
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+      "avatar_url": "https://avatars1.githubusercontent.com/u/22516154?v=4",
+      "profile": "https://github.com/thomasoss",
+      "contributions": [
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+      "avatar_url": "https://avatars1.githubusercontent.com/u/6075379?v=4",
+      "profile": "https://github.com/anuragagarwal561994",
+      "contributions": [
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+      "name": "Markus Moser",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/3317416?v=4",
+      "profile": "https://markusmo3.github.io",
+      "contributions": [
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+        "code",
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+      "name": "Sabiq Ihab",
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+      "contributions": [
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+      "avatar_url": "https://avatars3.githubusercontent.com/u/5253764?v=4",
+      "profile": "http://inbravo.github.io",
+      "contributions": [
+        "code"
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+      "contributions": [
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+      "contributions": [
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+      "contributions": [
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+        "doc"
+      ]
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+      "profile": "https://kemitix.github.io/",
+      "contributions": [
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+      ]
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+      "avatar_url": "https://avatars0.githubusercontent.com/u/22822639?v=4",
+      "profile": "https://github.com/Argyro-Sioziou",
+      "contributions": [
+        "code"
+      ]
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+      "name": "TylerMcConville",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/4946449?v=4",
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+      "contributions": [
+        "code"
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+      "contributions": [
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+      ]
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+      "avatar_url": "https://avatars2.githubusercontent.com/u/10725674?v=4",
+      "profile": "http://colinbut.com",
+      "contributions": [
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+      "avatar_url": "https://avatars2.githubusercontent.com/u/1503411?v=4",
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+      "contributions": [
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+      "name": "Juho Kang",
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+      "profile": "https://github.com/JuhoKang",
+      "contributions": [
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+      "avatar_url": "https://avatars2.githubusercontent.com/u/7002230?v=4",
+      "profile": "https://github.com/dheeraj-mummareddy",
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+        "code"
+      ]
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+      "name": "Bernardo Sulzbach",
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+      "profile": "https://www.bernardosulzbach.com",
+      "contributions": [
+        "code"
+      ]
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+    {
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+      "name": "Aleksandar Dudukovic",
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+      "profile": "https://github.com/4lexis",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
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+      "name": "Yusuf Aytaş",
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+      "profile": "https://www.yusufaytas.com",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "qpi",
+      "name": "Mihály Kuprivecz",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/1001491?v=4",
+      "profile": "http://futurehomes.hu",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "kapinuss",
+      "name": "Stanislav Kapinus",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/17639945?v=4",
+      "profile": "https://github.com/kapinuss",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "gvsharma",
+      "name": "GVSharma",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/6648152?v=4",
+      "profile": "https://github.com/gvsharma",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "SrdjanPaunovic",
+      "name": "Srđan Paunović",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/22815104?v=4",
+      "profile": "https://github.com/SrdjanPaunovic",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "sideris",
+      "name": "Petros G. Sideris",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/5484694?v=4",
+      "profile": "https://sideris.xyz/",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "MSaifAsif",
+      "name": "M Saif Asif",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/6280554?v=4",
+      "profile": "https://github.com/MSaifAsif",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "kanwarpreet25",
+      "name": "kanwarpreet25",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/39183641?v=4",
+      "profile": "https://github.com/kanwarpreet25",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "leonmak",
+      "name": "Leon Mak",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/13071508?v=4",
+      "profile": "http://leonmak.me",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "perwramdemark",
+      "name": "Per Wramdemark",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/7052193?v=4",
+      "profile": "http://www.wramdemark.se",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "waisuan",
+      "name": "Evan Sia Wai Suan",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/10975700?v=4",
+      "profile": "https://github.com/waisuan",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "AnaghaSasikumar",
+      "name": "AnaghaSasikumar",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/42939261?v=4",
+      "profile": "https://github.com/AnaghaSasikumar",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "christofferh",
+      "name": "Christoffer Hamberg",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/767643?v=4",
+      "profile": "https://christofferh.com",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "dgruntz",
+      "name": "Dominik Gruntz",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/1516800?v=4",
+      "profile": "https://github.com/dgruntz",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "hannespernpeintner",
+      "name": "Hannes",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/1679437?v=4",
+      "profile": "https://bitbucket.org/hannespernpeintner/",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "leogtzr",
+      "name": "Leo Gutiérrez Ramírez",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/1211969?v=4",
+      "profile": "https://github.com/leogtzr",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "npczwh",
+      "name": "Zhang WH",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/14066422?v=4",
+      "profile": "https://github.com/npczwh",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "oconnelc",
+      "name": "Christopher O'Connell",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/1112973?v=4",
+      "profile": "https://github.com/oconnelc",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "giorgosmav21",
+      "name": "George Mavroeidis",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/22855493?v=4",
+      "profile": "https://github.com/giorgosmav21",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "hbothra15",
+      "name": "Hemant Bothra",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/7418012?v=4",
+      "profile": "https://github.com/hbothra15",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "igeligel",
+      "name": "Kevin Peters",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/12736734?v=4",
+      "profile": "https://www.kevinpeters.net/about/",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "llorllale",
+      "name": "George Aristy",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/2019896?v=4",
+      "profile": "https://llorllale.github.io/",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "mookkiah",
+      "name": "Mahendran Mookkiah",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/8975264?v=4",
+      "profile": "https://github.com/mookkiah",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "Azureyjt",
+      "name": "Azureyjt",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/18476317?v=4",
+      "profile": "https://github.com/Azureyjt",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "vehpsr",
+      "name": "gans",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/3133265?v=4",
+      "profile": "https://github.com/vehpsr",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "ThatGuyWithTheHat",
+      "name": "Matt",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/24470582?v=4",
+      "profile": "https://github.com/ThatGuyWithTheHat",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "gopinath-langote",
+      "name": "Gopinath Langote",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/10210778?v=4",
+      "profile": "https://www.linkedin.com/in/gopinathlangote/",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "hoswey",
+      "name": "Hoswey",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/3689445?v=4",
+      "profile": "https://github.com/hoswey",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "amit2103",
+      "name": "Amit Pandey",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/7566692?v=4",
+      "profile": "https://github.com/amit2103",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "gwildor28",
+      "name": "gwildor28",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/16000365?v=4",
+      "profile": "https://github.com/gwildor28",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "llitfkitfk",
+      "name": "田浩",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/2404785?v=4",
+      "profile": "https://t.me/paul_docker",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "pitsios-s",
+      "name": "Stamatis Pitsios",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/6773603?v=4",
+      "profile": "https://twitter.com/StPitsios",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "qza",
+      "name": "qza",
+      "avatar_url": "https://avatars3.githubusercontent.com/u/233149?v=4",
+      "profile": "https://github.com/qza",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "Tschis",
+      "name": "Rodolfo Forte",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/20662669?v=4",
+      "profile": "http://tschis.github.io",
+      "contributions": [
+        "content"
+      ]
+    },
+    {
+      "login": "ankurkaushal",
+      "name": "Ankur Kaushal",
+      "avatar_url": "https://avatars2.githubusercontent.com/u/2236616?v=4",
+      "profile": "https://github.com/ankurkaushal",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "okinskas",
+      "name": "Ovidijus Okinskas",
+      "avatar_url": "https://avatars0.githubusercontent.com/u/20372387?v=4",
+      "profile": "https://www.linkedin.com/in/ovidijus-okinskas/",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "robertt240",
+      "name": "Robert Kasperczyk",
+      "avatar_url": "https://avatars1.githubusercontent.com/u/9137432?v=4",
+      "profile": "https://github.com/robertt240",
+      "contributions": [
+        "code"
+      ]
+    }
+  ],
+  "contributorsPerLine": 4,
+  "projectName": "java-design-patterns",
+  "projectOwner": "iluwatar",
+  "repoType": "github",
+  "repoHost": "https://github.com",
+  "skipCi": true
+}
--- a/.github/FUNDING.yml
+++ b/.github/FUNDING.yml
@ -0,0 +1 @@
+github: [iluwatar]
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@ -0,0 +1,60 @@
+#
+# The MIT License
+# Copyright © 2014-2019 Ilkka Seppälä
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+#
+
+# This workflow will build a Java project with Maven
+# For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven
+
+name: Java CI with Maven
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-18.04
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up JDK 11
+      uses: actions/setup-java@v1
+      with:
+        java-version: 11
+    # Some tests need screen access
+    - name: Install xvfb
+      run: sudo apt-get install xvfb
+    # SonarQube scan does not work for forked repositories
+    # See https://jira.sonarsource.com/browse/MMF-1371
+    - name: Build with Maven
+      if: github.ref != 'refs/heads/master'
+      run: xvfb-run mvn clean verify
+    - name: Build with Maven and run SonarQube analysis
+      if: github.ref == 'refs/heads/master'
+      run: xvfb-run mvn clean verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonar
+      env:
+        # These two env variables are needed for sonar analysis
+        GITHUB_TOKEN: ${{ secrets.REPOSITORY_ACCESS_TOKEN }}
+        SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
--- a/.gitignore
+++ b/.gitignore
@ -1,19 +1,19 @@
-target
-.metadata
-.settings
-.classpath
-.project
-*.class
-# Package Files #
-*.jar
-*.war
-*.ear
-.idea
-*.iml
-*.swp
+target
+.metadata
+.settings
+.classpath
+.project
+*.class
+# Package Files #
+*.jar
+*.war
+*.ear
+.idea
+*.iml
+*.swp
 datanucleus.log
 /bin/
 /bin/
 /bin/
-
-data-mapper/src/main/resources/log4j.xml
+*.log
+event-sourcing/Journal.json
--- a/.travis.yml
+++ b/.travis.yml
@ -1,38 +0,0 @@
-language: java
-jdk:
- oraclejdk8
-
-env:
-  global:
-  - GH_REF: github.com/iluwatar/java-design-patterns.git
-  - secure: LxTDuNS/rBWIvKkaEqr79ImZAe48mCdoYCF41coxNXgNoippo4GIBArknqtv+XvdkiuRZ1yGyj6pn8GU33c/yn+krddTUkVCwTbVatbalW5jhQjDbHYym/JcxaK9ZS/3JTeGcWrBgiPqHEEDhCf26vPZsXoMSeVCEORVKTp1BSg=
-  
-before_install:
- export DISPLAY=:99.0
- sh -e /etc/init.d/xvfb start
-
-# default install command is just "mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V"
-install:
- mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V -e
-
-after_success:
- mvn clean test jacoco:report coveralls:report
- bash update-ghpages.sh
-
-# use latest java version available instead of travis default
-addons:
-  apt:
-    packages:
-      - oracle-java8-installer
-
-notifications:
-  email:
-    - iluwatar@gmail.com
-  webhooks:
-    urls:
-      - https://webhooks.gitter.im/e/3319623945358a093a6f
-    on_success: change  # options: [always|never|change] default: always
-    on_failure: always  # options: [always|never|change] default: always
-    on_start: never     # options: [always|never|change] default: always
-
-sudo: false # route the build to the container-based infrastructure for a faster build
--- a/CODE_COVERAGE.md
+++ b/CODE_COVERAGE.md
@ -1,13 +0,0 @@
-# Code Coverage Report generation
-
-To generate the code coverage report, execute the following command:
-> mvn clean verify
-
-This will generate code coverage report in each of the modules. In order to view the same, open the following file in your browser.
-> target/site/jacoco/index.html 
-
-Please note that the above folder is created under each of the modules. For example:
-* adapter/target/site/jacoco/index.html 
-* busniess-delegate/target/site/jacoco/index.html 
-
-
--- a/LICENSE.md
+++ b/LICENSE.md
@ -1,6 +1,6 @@
 The MIT License (MIT)

-Copyright (c) 2014-2016 Ilkka Seppälä
+Copyright (c) 2014-2020 Ilkka Seppälä

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
--- a/PULL_REQUEST_TEMPLATE.md
+++ b/PULL_REQUEST_TEMPLATE.md
@ -0,0 +1,15 @@
+
+Pull request title
+
+- Clearly and concisely describes what it does
+- Refer to the issue that it solves, if available
+
+
+Pull request description
+
+- Describes the main changes that come with the pull request
+- Any relevant additional information is provided
+
+
+
+> For detailed contributing instructions see https://github.com/iluwatar/java-design-patterns/wiki/01.-How-to-contribute
--- a/README.md
+++ b/README.md
@ -4,44 +4,166 @@

 # Design patterns implemented in Java

-[![Build status](https://travis-ci.org/iluwatar/java-design-patterns.svg?branch=master)](https://travis-ci.org/iluwatar/java-design-patterns)
-[![Coverage Status](https://coveralls.io/repos/iluwatar/java-design-patterns/badge.svg?branch=master)](https://coveralls.io/r/iluwatar/java-design-patterns?branch=master)
+![Java CI with Maven](https://github.com/iluwatar/java-design-patterns/workflows/Java%20CI%20with%20Maven/badge.svg)
 [![License MIT](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/iluwatar/java-design-patterns/master/LICENSE.md)
 [![Join the chat at https://gitter.im/iluwatar/java-design-patterns](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/iluwatar/java-design-patterns?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![Sonarcloud Status](https://sonarcloud.io/api/project_badges/measure?project=iluwatar_java-design-patterns&metric=alert_status)](https://sonarcloud.io/dashboard?id=iluwatar_java-design-patterns) 
+<!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
+[![All Contributors](https://img.shields.io/badge/all_contributors-32-orange.svg?style=flat-square)](#contributors-)
+<!-- ALL-CONTRIBUTORS-BADGE:END -->

 # Introduction

-Design patterns are formalized best practices that the programmer can use to
+Design patterns are the best formalized practices a programmer can use to
 solve common problems when designing an application or system.

 Design patterns can speed up the development process by providing tested, proven
 development paradigms.

-Reusing design patterns helps to prevent subtle issues that can cause major
+Reusing design patterns help prevent subtle issues that cause major
 problems, and it also improves code readability for coders and architects who
 are familiar with the patterns.

 # Getting started

+This site showcases Java Design Patterns. The solutions have been developed by
+experienced programmers and architects from the open source community. The 
+patterns can be browsed by their high level descriptions or by looking at their
+source code. The source code examples are well commented and can be thought as
+programming tutorials how to implement a specific pattern. We use the most
+popular battle-proven open source Java technologies.
+
 Before you dive into the material, you should be familiar with various
-Programming/Software Design Principles.
+[Software Design Principles](https://java-design-patterns.com/principles/).

 All designs should be as simple as possible. You should start with KISS, YAGNI,
 and Do The Simplest Thing That Could Possibly Work principles. Complexity and
 patterns should only be introduced when they are needed for practical
 extensibility.

-Once you are familiar with these concepts you can start drilling down into
-patterns by any of the following approaches
+Once you are familiar with these concepts you can start drilling down into the
+[available design patterns](https://java-design-patterns.com/patterns/) by any 
+of the following approaches

- - Using difficulty tags, `Difficulty-Beginner`, `Difficulty-Intermediate` & `Difficulty-Expert`.
- - Using pattern categories, `Creational`, `Behavioral` and others.
- - Search for a specific pattern. Can't find one? Please report a new pattern [here](https://github.com/iluwatar/java-design-patterns/issues).
+ - Search for a specific pattern by name. Can't find one? Please report a new pattern [here](https://github.com/iluwatar/java-design-patterns/issues).
+ - Using tags such as `Performance`, `Gang of Four` or `Data access`.
+ - Using pattern categories, `Creational`, `Behavioral`, and others.
+
+Hopefully you find the object oriented solutions presented on this site useful
+in your architectures and have as much fun learning them as we had developing them.

 # How to contribute

-If you are willing to contribute to the project you will find the relevant information in our [developer wiki](https://github.com/iluwatar/java-design-patterns/wiki). We will help you and answer your questions in the [Gitter chatroom](https://gitter.im/iluwatar/java-design-patterns).
+If you are willing to contribute to the project you will find the relevant information in 
+our [developer wiki](https://github.com/iluwatar/java-design-patterns/wiki). We will help 
+you and answer your questions in the [Gitter chatroom](https://gitter.im/iluwatar/java-design-patterns).

 # License

 This project is licensed under the terms of the MIT license.
+
+# Contributors
+
+<!-- ALL-CONTRIBUTORS-LIST:START - Do not remove or modify this section -->
+<!-- prettier-ignore-start -->
+<!-- markdownlint-disable -->
+<table>
+  <tr>
+    <td align="center"><a href="https://github.com/iluwatar"><img src="https://avatars1.githubusercontent.com/u/582346?v=4" width="100px;" alt=""/><br /><sub><b>Ilkka Seppälä</b></sub></a><br /><a href="#projectManagement-iluwatar" title="Project Management">📆</a> <a href="#maintenance-iluwatar" title="Maintenance">🚧</a> <a href="#content-iluwatar" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/amit1307"><img src="https://avatars0.githubusercontent.com/u/23420222?v=4" width="100px;" alt=""/><br /><sub><b>amit1307</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=amit1307" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/npathai"><img src="https://avatars2.githubusercontent.com/u/1792515?v=4" width="100px;" alt=""/><br /><sub><b>Narendra Pathai</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=npathai" title="Code">💻</a> <a href="#ideas-npathai" title="Ideas, Planning, & Feedback">🤔</a> <a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Anpathai" title="Reviewed Pull Requests">👀</a></td>
+    <td align="center"><a href="https://github.com/fluxw42"><img src="https://avatars1.githubusercontent.com/u/1545460?v=4" width="100px;" alt=""/><br /><sub><b>Jeroen Meulemeester</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=fluxw42" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="http://www.joemccarthy.co.uk"><img src="https://avatars0.githubusercontent.com/u/4526195?v=4" width="100px;" alt=""/><br /><sub><b>Joseph McCarthy</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=mikulucky" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/thomasoss"><img src="https://avatars1.githubusercontent.com/u/22516154?v=4" width="100px;" alt=""/><br /><sub><b>Thomas</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=thomasoss" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/anuragagarwal561994"><img src="https://avatars1.githubusercontent.com/u/6075379?v=4" width="100px;" alt=""/><br /><sub><b>Anurag Agarwal</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=anuragagarwal561994" title="Code">💻</a></td>
+    <td align="center"><a href="https://markusmo3.github.io"><img src="https://avatars1.githubusercontent.com/u/3317416?v=4" width="100px;" alt=""/><br /><sub><b>Markus Moser</b></sub></a><br /><a href="#design-markusmo3" title="Design">🎨</a> <a href="https://github.com/iluwatar/java-design-patterns/commits?author=markusmo3" title="Code">💻</a> <a href="#ideas-markusmo3" title="Ideas, Planning, & Feedback">🤔</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://twitter.com/i_sabiq"><img src="https://avatars1.githubusercontent.com/u/19510920?v=4" width="100px;" alt=""/><br /><sub><b>Sabiq Ihab</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=isabiq" title="Code">💻</a></td>
+    <td align="center"><a href="http://inbravo.github.io"><img src="https://avatars3.githubusercontent.com/u/5253764?v=4" width="100px;" alt=""/><br /><sub><b>Amit Dixit</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=inbravo" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/piyushchaudhari04"><img src="https://avatars3.githubusercontent.com/u/10268029?v=4" width="100px;" alt=""/><br /><sub><b>Piyush Kailash Chaudhari</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=piyushchaudhari04" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/joshzambales"><img src="https://avatars1.githubusercontent.com/u/8704552?v=4" width="100px;" alt=""/><br /><sub><b>joshzambales</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=joshzambales" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/Crossy147"><img src="https://avatars2.githubusercontent.com/u/7272996?v=4" width="100px;" alt=""/><br /><sub><b>Kamil Pietruszka</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Crossy147" title="Code">💻</a></td>
+    <td align="center"><a href="http://cs.joensuu.fi/~zkhayda"><img src="https://avatars2.githubusercontent.com/u/660742?v=4" width="100px;" alt=""/><br /><sub><b>Zafar Khaydarov</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=zafarella" title="Code">💻</a> <a href="https://github.com/iluwatar/java-design-patterns/commits?author=zafarella" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://kemitix.github.io/"><img src="https://avatars1.githubusercontent.com/u/1147749?v=4" width="100px;" alt=""/><br /><sub><b>Paul Campbell</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=kemitix" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/Argyro-Sioziou"><img src="https://avatars0.githubusercontent.com/u/22822639?v=4" width="100px;" alt=""/><br /><sub><b>Argyro Sioziou</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Argyro-Sioziou" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/TylerMcConville"><img src="https://avatars0.githubusercontent.com/u/4946449?v=4" width="100px;" alt=""/><br /><sub><b>TylerMcConville</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=TylerMcConville" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/saksham93"><img src="https://avatars1.githubusercontent.com/u/37399540?v=4" width="100px;" alt=""/><br /><sub><b>saksham93</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=saksham93" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/nikhilbarar"><img src="https://avatars2.githubusercontent.com/u/37332144?v=4" width="100px;" alt=""/><br /><sub><b>nikhilbarar</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=nikhilbarar" title="Code">💻</a></td>
+    <td align="center"><a href="http://colinbut.com"><img src="https://avatars2.githubusercontent.com/u/10725674?v=4" width="100px;" alt=""/><br /><sub><b>Colin But</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=colinbut" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/ruslanpa"><img src="https://avatars2.githubusercontent.com/u/1503411?v=4" width="100px;" alt=""/><br /><sub><b>Ruslan</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ruslanpa" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/JuhoKang"><img src="https://avatars1.githubusercontent.com/u/4745294?v=4" width="100px;" alt=""/><br /><sub><b>Juho Kang</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=JuhoKang" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/dheeraj-mummareddy"><img src="https://avatars2.githubusercontent.com/u/7002230?v=4" width="100px;" alt=""/><br /><sub><b>Dheeraj Mummareddy</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=dheeraj-mummareddy" title="Code">💻</a></td>
+    <td align="center"><a href="https://www.bernardosulzbach.com"><img src="https://avatars0.githubusercontent.com/u/8271090?v=4" width="100px;" alt=""/><br /><sub><b>Bernardo Sulzbach</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=bernardosulzbach" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/4lexis"><img src="https://avatars0.githubusercontent.com/u/19871727?v=4" width="100px;" alt=""/><br /><sub><b>Aleksandar Dudukovic</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=4lexis" title="Code">💻</a></td>
+    <td align="center"><a href="https://www.yusufaytas.com"><img src="https://avatars2.githubusercontent.com/u/1049483?v=4" width="100px;" alt=""/><br /><sub><b>Yusuf Aytaş</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=yusufaytas" title="Code">💻</a></td>
+    <td align="center"><a href="http://futurehomes.hu"><img src="https://avatars2.githubusercontent.com/u/1001491?v=4" width="100px;" alt=""/><br /><sub><b>Mihály Kuprivecz</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=qpi" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/kapinuss"><img src="https://avatars0.githubusercontent.com/u/17639945?v=4" width="100px;" alt=""/><br /><sub><b>Stanislav Kapinus</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=kapinuss" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/gvsharma"><img src="https://avatars1.githubusercontent.com/u/6648152?v=4" width="100px;" alt=""/><br /><sub><b>GVSharma</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=gvsharma" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/SrdjanPaunovic"><img src="https://avatars1.githubusercontent.com/u/22815104?v=4" width="100px;" alt=""/><br /><sub><b>Srđan Paunović</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=SrdjanPaunovic" title="Code">💻</a></td>
+    <td align="center"><a href="https://sideris.xyz/"><img src="https://avatars3.githubusercontent.com/u/5484694?v=4" width="100px;" alt=""/><br /><sub><b>Petros G. Sideris</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=sideris" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/npczwh"><img src="https://avatars0.githubusercontent.com/u/14066422?v=4" width="100px;" alt=""/><br /><sub><b>Zhang WH</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=npczwh" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/qza"><img src="https://avatars3.githubusercontent.com/u/233149?v=4" width="100px;" alt=""/><br /><sub><b>qza</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=qza" title="Code">💻</a></td>
+    <td align="center"><a href="http://tschis.github.io"><img src="https://avatars1.githubusercontent.com/u/20662669?v=4" width="100px;" alt=""/><br /><sub><b>Rodolfo Forte</b></sub></a><br /><a href="#content-Tschis" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/ankurkaushal"><img src="https://avatars2.githubusercontent.com/u/2236616?v=4" width="100px;" alt=""/><br /><sub><b>Ankur Kaushal</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ankurkaushal" title="Code">💻</a></td>
+    <td align="center"><a href="https://www.linkedin.com/in/ovidijus-okinskas/"><img src="https://avatars0.githubusercontent.com/u/20372387?v=4" width="100px;" alt=""/><br /><sub><b>Ovidijus Okinskas</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=okinskas" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://twitter.com/StPitsios"><img src="https://avatars1.githubusercontent.com/u/6773603?v=4" width="100px;" alt=""/><br /><sub><b>Stamatis Pitsios</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=pitsios-s" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/robertt240"><img src="https://avatars1.githubusercontent.com/u/9137432?v=4" width="100px;" alt=""/><br /><sub><b>Robert Kasperczyk</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=robertt240" title="Code">💻</a></td>
+    <td align="center"><a href="https://t.me/paul_docker"><img src="https://avatars1.githubusercontent.com/u/2404785?v=4" width="100px;" alt=""/><br /><sub><b>田浩</b></sub></a><br /><a href="#content-llitfkitfk" title="Content">🖋</a></td>
+    <td align="center"><a href="https://github.com/gwildor28"><img src="https://avatars0.githubusercontent.com/u/16000365?v=4" width="100px;" alt=""/><br /><sub><b>gwildor28</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=gwildor28" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/amit2103"><img src="https://avatars3.githubusercontent.com/u/7566692?v=4" width="100px;" alt=""/><br /><sub><b>Amit Pandey</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=amit2103" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/hoswey"><img src="https://avatars3.githubusercontent.com/u/3689445?v=4" width="100px;" alt=""/><br /><sub><b>Hoswey</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=hoswey" title="Code">💻</a></td>
+    <td align="center"><a href="https://www.linkedin.com/in/gopinathlangote/"><img src="https://avatars2.githubusercontent.com/u/10210778?v=4" width="100px;" alt=""/><br /><sub><b>Gopinath Langote</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=gopinath-langote" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/ThatGuyWithTheHat"><img src="https://avatars0.githubusercontent.com/u/24470582?v=4" width="100px;" alt=""/><br /><sub><b>Matt</b></sub></a><br /><a href="#content-ThatGuyWithTheHat" title="Content">🖋</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/vehpsr"><img src="https://avatars2.githubusercontent.com/u/3133265?v=4" width="100px;" alt=""/><br /><sub><b>gans</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=vehpsr" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/Azureyjt"><img src="https://avatars2.githubusercontent.com/u/18476317?v=4" width="100px;" alt=""/><br /><sub><b>Azureyjt</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Azureyjt" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/mookkiah"><img src="https://avatars1.githubusercontent.com/u/8975264?v=4" width="100px;" alt=""/><br /><sub><b>Mahendran Mookkiah</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=mookkiah" title="Code">💻</a></td>
+    <td align="center"><a href="https://llorllale.github.io/"><img src="https://avatars1.githubusercontent.com/u/2019896?v=4" width="100px;" alt=""/><br /><sub><b>George Aristy</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=llorllale" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://www.kevinpeters.net/about/"><img src="https://avatars1.githubusercontent.com/u/12736734?v=4" width="100px;" alt=""/><br /><sub><b>Kevin Peters</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=igeligel" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/hbothra15"><img src="https://avatars1.githubusercontent.com/u/7418012?v=4" width="100px;" alt=""/><br /><sub><b>Hemant Bothra</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=hbothra15" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/giorgosmav21"><img src="https://avatars2.githubusercontent.com/u/22855493?v=4" width="100px;" alt=""/><br /><sub><b>George Mavroeidis</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=giorgosmav21" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/oconnelc"><img src="https://avatars0.githubusercontent.com/u/1112973?v=4" width="100px;" alt=""/><br /><sub><b>Christopher O'Connell</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=oconnelc" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/leogtzr"><img src="https://avatars0.githubusercontent.com/u/1211969?v=4" width="100px;" alt=""/><br /><sub><b>Leo Gutiérrez Ramírez</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=leogtzr" title="Code">💻</a></td>
+    <td align="center"><a href="https://bitbucket.org/hannespernpeintner/"><img src="https://avatars3.githubusercontent.com/u/1679437?v=4" width="100px;" alt=""/><br /><sub><b>Hannes</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=hannespernpeintner" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/dgruntz"><img src="https://avatars0.githubusercontent.com/u/1516800?v=4" width="100px;" alt=""/><br /><sub><b>Dominik Gruntz</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=dgruntz" title="Code">💻</a></td>
+    <td align="center"><a href="https://christofferh.com"><img src="https://avatars1.githubusercontent.com/u/767643?v=4" width="100px;" alt=""/><br /><sub><b>Christoffer Hamberg</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=christofferh" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/AnaghaSasikumar"><img src="https://avatars2.githubusercontent.com/u/42939261?v=4" width="100px;" alt=""/><br /><sub><b>AnaghaSasikumar</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=AnaghaSasikumar" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/waisuan"><img src="https://avatars2.githubusercontent.com/u/10975700?v=4" width="100px;" alt=""/><br /><sub><b>Evan Sia Wai Suan</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=waisuan" title="Code">💻</a></td>
+    <td align="center"><a href="http://www.wramdemark.se"><img src="https://avatars2.githubusercontent.com/u/7052193?v=4" width="100px;" alt=""/><br /><sub><b>Per Wramdemark</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=perwramdemark" title="Code">💻</a></td>
+    <td align="center"><a href="http://leonmak.me"><img src="https://avatars3.githubusercontent.com/u/13071508?v=4" width="100px;" alt=""/><br /><sub><b>Leon Mak</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=leonmak" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/kanwarpreet25"><img src="https://avatars0.githubusercontent.com/u/39183641?v=4" width="100px;" alt=""/><br /><sub><b>kanwarpreet25</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=kanwarpreet25" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/MSaifAsif"><img src="https://avatars1.githubusercontent.com/u/6280554?v=4" width="100px;" alt=""/><br /><sub><b>M Saif Asif</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=MSaifAsif" title="Code">💻</a></td>
+  </tr>
+</table>
+
+<!-- markdownlint-enable -->
+<!-- prettier-ignore-end -->
+<!-- ALL-CONTRIBUTORS-LIST:END -->
--- a/_scripts/postPumlsToServer.firstrun.output
+++ b/_scripts/postPumlsToServer.firstrun.output
@ -1,190 +0,0 @@
-parent: half-sync-half-async; artifact: half-sync-half-async
-Puml Server ID: RScv3SCm3030LU819FRPXg5fIm552tnYPFiyjRi3RkbAaYkdoQr5JBy369vrxz7oaSv6XmPhL3e6TCaJ0msU-CAoilTToyG8DdKOw5z0GzcAlvNAN_WZSD1brBHHPmxv0000
-parent: abstract-document; artifact: abstract-document
-Puml Server ID: PSjB3eCm34NHhPG599vtDyQn85L-ifzX-p3lxEf8Twj3MXGDQvyJMFubChxpKN767gucSq07iinEjSNDOACVNvoAUZr6MWoe3QVE_WRnxZ0Mf38b-hkIGlurX_MyehS7
-parent: tolerant-reader; artifact: tolerant-reader
-Puml Server ID: NSZ14SCm20NHLf829ExfXaYChGn26lZ4xSVdtFRjSrZJx9AkZnFOyI9olkenSEOxGxmjWnXgMvE6viLWfmz_kNI9SLZP38XRqEIuWx1Kd0t5XVjjGVj_DNtMdLD_
-parent: event-driven-architecture; artifact: event-driven-architecture
-Puml Server ID: TOhH3SCW30LNQGS0_tSRnrZ15H1adfFromBzkfFktZQaHT7mzgh0N1yYvoUVXXf7B7Mv1dGWozN9MZmCTlhopQdeidEaoO3wMDHvRI6zzvwAssPYbsfGGRYIGlxN7DxpZDv-
-parent: publish-subscribe; artifact: publish-subscribe
-Puml Server ID: PSZB3SCm203GLTe1RExT1XCKKs5YyMdMR--zFRsd66aTNAwFcRdZ1U1uzrDorgXWfykIBJjT2qJhnaI7Dtwm7HnoMjkOoMu12-C7s3LKOhQe4UGo63ZfVtlvwhkMVW40
-parent: facade; artifact: facade
-Puml Server ID: BSP15eCm20N0gxG7CEoz3ILKqvTW7dpq-hhehERTJ7fMJU-l7PYn4ZbVPMlOyvEXBeT13KMEGQtdnM2d7v-yL8sssJ8PKBUWmV64lYnSbHJoRqaVPUReDm00
-parent: service-locator; artifact: service-locator
-Puml Server ID: NSjB3iCm203HgxG7iDdtDeIWX0fZYqzo_MRTtUX9ynOZhPtBzNLchlW0EDxza3nhgs2dQScMdUO0qRenqU6B5xQTGmvh2pFPBM1WF07FSmbnqqcOqu6J_gsNZxvgw0y0
-parent: dao; artifact: dao
-Puml Server ID: 5SR14OKW30N0LhG0oVrt4o6ZE12Ov4NR_thQNQlc5aN2sd82qtz4naywAixOmyNoK8WYvT6fjdWOR7JnpLiHhuTkam4nTUhiRwZm847-J64zpUZj3m00
-parent: model-view-presenter; artifact: model-view-presenter
-Puml Server ID: ROlR3SGW3C1MkGu0-RzjKeXQJWcWFChwPO3xispvQBrmL0hbp-q-xGkWkFBL_8upZBICxjGzbo7GE1OwAlpmmLJ9sjNJH7VIRY1e6q169KvFevMcakrtI_BoD-HGoJE4Nm00
-parent: observer; artifact: observer
-Puml Server ID: FSkn4OGm30NHLg00hFow4KO3PcpP8tr1-pYwx6smQz5Suv2mkbp0y1-HyPlEWYlsSB7S5Q98kJSgDLu66ztyy7Q8brEtmO2OEZNs2Uhxl9u9GVv72cjfHAiV
-parent: intercepting-filter; artifact: intercepting-filter
-Puml Server ID: RSfB3i8m303Hgy014k-vZN5DQkIuaJ_q-fGzkz7JtCL8Q-DolUsPAnu0ZcSVadizAzZfi6JBJiS4qJenqU6D7smRXmnh2pFPBM1YN05o_KwyKcoqb-ZFEEcVz_BPLqtz0W00
-parent: factory-method; artifact: factory-method
-Puml Server ID: NSZB3G8n30N0Lg20n7UwCOxPP9MVx6TMT0zdRgEvjoazYeRrMmMsFuYChtmqr7Y6gycQq8aiQr3hSJ7OwEGtfwBUZfas0shJQR3_G2yMBFkaeQYha4B-AeUDl6FqBm00
-parent: private-class-data; artifact: private-class-data
-Puml Server ID: RShR3SCm243HLTe1RFwx3S4eeSB4uf6itmpGlwkZ-nOZhS7b-ZeoLtm07E--InwrLR3JQScMdSu9edLZeiCNBso3GtPh2pFPBM1YF07BvSBaHeeHRJm_SD8VxkMphvhw0m00
-parent: async-method-invocation; artifact: async-method-invocation
-Puml Server ID: TSdB3SCW303GLTe1mFTkunWhk0A3_4dKxTi5UdlIUuhIoCPfuz4Zjhy03EzwIlGyqjbeQR16fJL1HjuOQF362qjZbrFBnWWsTPZeFm3wHwbCZhvQ4RqMOSXIuA1_LzDctJd75m00
-parent: execute-around; artifact: execute-around
-Puml Server ID: NSZ14G8n20NGLhI0XBlT865suoGa0n_NylNixSsxTvEHJTF7xGHsF8YShtfqdFdCK9TbK4ELDQcFl1ZizE8tbwRH3okR0NKBcXm_a7vK4bhOLreZXVnLJPzrvnnV
-parent: monostate; artifact: monostate
-Puml Server ID: HSV14OGm20NGLjO23FVj1YEZsGaa0nzjVxrvUszfLdlkaju_9p3ZI-HybwFXp2r3l0w364eTIgtdpM2d7r-yxXBji7Ko86v1ol60TDW8C8G4zLr9rp9J-ny0
-parent: thread-pool; artifact: thread-pool
-Puml Server ID: JSV14SCW30J0Lk82GFzq8uF6a1624IUx_UIPt-xHhMXK2TTN0zP-4pa_-UfeSSOMBzCWXbpceAxnCDZfmpUdAhjVbXO3uhPfyFw1q5oufZMdag3yFuUFl6Be5m00
-parent: delegation; artifact: delegation
-Puml Server ID: JSV14GCX20NGLf82LkxfXbN69OFeu2VRVdBCxRsdUhLiac6F2rZxHHHybwwuyimjKQT37ANEGMfvCpZepHy-ccpjVYm697pJuFq3DJ7f39rEWlhNaZ7Aoc5V
-parent: chain; artifact: chain
-Puml Server ID: 9SR13SCm20NGLTe1OkxTXX0KKzd4Wa-pVYlrdTxJN4OTMZ4U7LZv8Wg-ssdejLTgoELGHvDhaesw6HpqvWzlXwQTlYq6D3nfSlv2qjcS5F9VgvXjrHnV
-parent: resource-acquisition-is-initialization; artifact: resource-acquisition-is-initialization
-Puml Server ID: ZShR3S8m343HLUW0YV_PnhXMQvGumOzMOdhA1lqxkhgBABLSEQqzzeZfJm33isuIUxxIsMXei4QbqK5QdXXeyCO3oyekcvQ94MpgqD4lWB6FDEA2z4bn2HbQn8leHMponNy13hgvrhHUP_Rs0m00
-parent: fluentinterface; artifact: fluentinterface
-Puml Server ID: NOj93eCm302_KXv0VEzlN6F0bMCYB_3zvjpRQ3IpY97MnkNwEZD7l04SdtP8dlMfOAVBaYqRNHr4wy54Xo_Uk6uSSjWwC9FT0Zh61DYrPY_pyXs9WPF-NIllRLJN7m00
-parent: service-layer; artifact: service-layer
-Puml Server ID: LOl93SCm3C1MQGUmzUysgY8aAcJ5q96WszVV_aW2V8gHriRb-ZWoPxm07E--Inxrhc2dqv8jEvq3HEl6H8SFNjWs3jcjJSnaju21iG3MSmbnK_mkuwJ_qij7dpNq1m00
-parent: visitor; artifact: visitor
-Puml Server ID: DSR14OGm20NGLhG0mtsxmSWeJa8oyD7sTo_xJczLgoqFIM_B1Spu43c_vLHSkMU8rs4GGwcZaxPy6UnqyyFR8Q6dRPC1SGlg7B_Gew4OJeBwVqdlPMPlNm00
-parent: double-dispatch; artifact: double-dispatch
-Puml Server ID: NSbB3iCW303HgpG70Ezx6yTOWSeOv4zp_MRTtUZDCPGa6wV9gqTiVmCOtlKQqVDCPwEbmHgLreGXUMEWmGU_M1hxkBHiZ61JXud-1BILft1fmvz37JZetshQh3kd_000
-parent: monad; artifact: monad
-Puml Server ID: 9SR13SCm20NGLPe1OkxTXjWeSMMm1Pza_LRgExsjMntP97syBc35cyZvAMV7bKU6U9q6CPGwbVh8Xy5E7xvvRnBzj7qn86v1ol4BwJHk9AZ_bNGjAtLy0G00
-parent: front-controller; artifact: front-controller
-Puml Server ID: PSlB3OGm303HLfO24j-t6nCC13bEvC_IFk6yjz6JPgbIE3OAvS_fFkmBe7Zde_ePQnXfwU8adajlK3bkT5Iuy8Tf8wk7f87kf6BGq6R0hlD8xwQTUG9v-SCSslA8nWy0
-parent: strategy; artifact: strategy
-Puml Server ID: FSV13OCm30NGLM00udktCS4AGOaJsTz5tRwSkBstLiqj3WbhombC_n0PtwbKdB67Y-MX44NAerDjSJFOwE8lRuTuBRfD1iJKgRC_88SnfFn8aD-ai9vczFO7
-parent: command; artifact: command
-Puml Server ID: DSgn4OCm30NGLM00h3xR25i7vYpXaxx2-g59zugtTgiZcwIFvGHcV8YSdt9qdBbdYDVR88PIRwK-yc6mqyLVtff4FsoR38XRa7Aye3SgMoD1_RkaQvcfumS0
-parent: abstract-factory; artifact: abstract-factory
-Puml Server ID: PSZB3OD034NHLa81Czwd6sCC39gVxEUWT1_ssLmTtQLqgR5fM7sTmFGtaV6TZu8prd0r6HtQaMKqAZLk1XjT_E6qgPUZfyc0MdTgx0-8LuUn8ErFXdr98NypXxKyezKV
-parent: flux; artifact: flux
-Puml Server ID: 7SP14eCm20NGg-W13FlU1YFLE0GpyAazVZk-rPkRLSrDqdKwW14l8kUxx0r7hXdYzJA8eTIhKzEy6UnqyeUNJQBjjWm6n2seS_n3Ryql2UgJajxBoAu_
-parent: event-aggregator; artifact: event-aggregator
-Puml Server ID: PSf13iCW30NHgxG70Ezx6uTOX0eCih-JwvTzTwEdUJSjFKu9wwyBMFuXCdvoRRZY21ShKo6ANEQWrkDXiD6NRqwdUAkQ5WDYwZJOTv3SUqzSgqbbp0qeVvZ3Hbun-Wy0
-parent: singleton; artifact: singleton
-Puml Server ID: HSV14SCm20J0Lk82BFxf1ikCh0n26ZZizfDVVhjRjwfvIhg-Bc35cyZvAQtZoYD3l4w364gTWxhcms2d3z-ydnAzsRuO4BUWmV43HRUcWcaagF-Lz55M3lq2
-parent: null-object; artifact: null-object
-Puml Server ID: JSV14SCm20J0Lk829Fxf1cF6bWSX3JhYzfDdVhjRSx4yDCDU5p3NcoZugMV3bNik3HaETLGPdPhbm-2WcpzS3btjz38PqF15dTSFv6bMndwhW1Jo_vhHwynkNm00
-parent: multiton; artifact: multiton
-Puml Server ID: FST14i8m20NGg-W16lRUXgPCYnD81Zxs-hfozzvJlOywf68yBc3bYoZuRgVYghrIea-7E5gVHZhgPd3Gcp-y7P9w-hOOaF0au_o1h0OKqqdG_saLrbRP-080
-parent: composite; artifact: composite
-Puml Server ID: HSf13eCm30NHgy01YFUzZGaM62LEP7-NwvTTT_EaMTLgoqFIst81Cpv4payv5LVk6U9r6CHGwkYaBHy6EztyvUsGqDEsoO2u1NMED-WTvmY5aA3-LT9xcTdR3m00
-parent: api-gateway; artifact: image-microservice
-Puml Server ID: 3Sp13SCm2030LTe1RFxTXX3aK1biOOZLxPlVlUujHZrFJk-lAsAk3u3ZhatYoYCNEmqBjgWq5AJdna27BzvOJbxIh4oCOBS5Yki1u9JIC7ZZ3pW8HB5nKI4VJtSBSKtNEbFx7m00
-I dont want to program this, just add the following lines to the README.md file that corresponds to this puml file 'api-gateway/etc/image-microservice.urm.puml'
-pumlid: 3Sp13SCm2030LTe1RFxTXX3aK1biOOZLxPlVlUujHZrFJk-lAsAk3u3ZhatYoYCNEmqBjgWq5AJdna27BzvOJbxIh4oCOBS5Yki1u9JIC7ZZ3pW8HB5nKI4VJtSBSKtNEbFx7m00
-parent: api-gateway; artifact: api-gateway-service
-Puml Server ID: JSox3SCm303HLP819FRUXg49cO542_nOyFPncUvUSszHwhbpMdyT4TCt0CDLcyIHdtGsEZLOez8vG7ek33JuueLbPvUcPM84cpeCz2S0fvI6mGjluA1_b-Tt2N5D6tNcw3y0
-I dont want to program this, just add the following lines to the README.md file that corresponds to this puml file 'api-gateway/etc/api-gateway-service.urm.puml'
-pumlid: JSox3SCm303HLP819FRUXg49cO542_nOyFPncUvUSszHwhbpMdyT4TCt0CDLcyIHdtGsEZLOez8vG7ek33JuueLbPvUcPM84cpeCz2S0fvI6mGjluA1_b-Tt2N5D6tNcw3y0
-parent: api-gateway; artifact: price-microservice
-Puml Server ID: 3Sn13iGW243HgqmFeEpdDfGIoqJK8DJqzkFklyq_f56DYyFgvtOVymjWk78Hl-ECoKQzEJVFr1Mana97Wny-c2wUKbeQwCxM9YZE7O13Ka7dXI-m4mmJugH2rlVksSXXcaTe_GC0
-I dont want to program this, just add the following lines to the README.md file that corresponds to this puml file 'api-gateway/etc/price-microservice.urm.puml'
-pumlid: 3Sn13iGW243HgqmFeEpdDfGIoqJK8DJqzkFklyq_f56DYyFgvtOVymjWk78Hl-ECoKQzEJVFr1Mana97Wny-c2wUKbeQwCxM9YZE7O13Ka7dXI-m4mmJugH2rlVksSXXcaTe_GC0
-parent: object-pool; artifact: object-pool
-Puml Server ID: JSV94SCm2030Lk829Fxf1cF6bWU1XYDkFtdcjxiD9Qc3o-LrPQvu0pW-_HnvrLx1JgR9cfrimf1wCD7XnW-sWsESsXPcicl0nFW1RB-PiYqp0KxwVo-VVTMKBm00
-parent: adapter; artifact: adapter
-Puml Server ID: DSR14S8m30J0Lg20M7-wEMnDOiPMFDA9j0yyUEtUkzMHJTF7xI1NF4GSLzaxZtncgDVJgCPIpobzv0N2vOKtjgRHTziMI7KBcOXl10thfxB-Nz9dMJd71m00
-parent: hexagonal; artifact: hexagonal
-Puml Server ID: HSTB4W8X30N0g-W1XkozpPD90LO8L3wEnzUTk-xxq2fvSfhSUiJs1v7XAcr4psSwMrqQh57gcZGaBmICNdZZEDb7qsCZWasT9lm7wln1MmeXZlfVIPjbvvGl
-parent: value-object; artifact: value-object
-Puml Server ID: LSZ13SCm20NGLTe1RExTXX2KECBOmfza_VRQszDxDnVBNJFiTG9pVOY2dteqdBdbqf3XK4ULqQbPFWmEklZcikjgXvV9W8Olwhn-e9ijjOpjKW4fv2zgHgypktq1
-parent: twin; artifact: twin
-Puml Server ID: 7SR13OCm30NGLUW0n7UsCS42eyH4zdUpFbNVwNtKQij3qjjo0ICs8kTPJiMLUuPuVGnYAFNff2qdWvrk_l9wIEXfws10t88wno-4gKQ2-az9xsLaRoy0
-parent: semaphore; artifact: semaphore
-Puml Server ID: HSV14SCm20J0Lk82BFxf1ikCfOn06ZZizfDVVhjRjphobFJnQi2ADv7pKwwEbaU6U9q6CPGwbVh8Xy5E7xvvFoNwPVjYGDo2bEC72b5URRgGeFvNqhMirF45
-parent: message-channel; artifact: message-channel
-Puml Server ID: NSZB3SCm203GLTe1RExTXX1akm9YyMdMRy-zFRtdCf8wkLmUCtF72y3nxcFbhAE2dIvBjknqAIof6nCTtlZ1TdAiOMrZ9hi5ACOFe1o1WnjDD6C1Jlg_NgvzbyeN
-parent: poison-pill; artifact: poison-pill
-Puml Server ID: JSZ14SCm20NHLf82BExfXiYCJGOX3NpYzkDZRllsgTwjTgcmnmciV145N-rGdFMkbEZJ8OxMvo2rkXWSzE4lRxka7huj1YGyQN3UGMjgpdkh6Gdwlrl5QAk6_G00
-parent: aggregator-microservices; artifact: aggregator-service
-Puml Server ID: JOov3SCm301NIGQGs7iRXYPa1g8ayB7NjuiKwGvtmBrbKC-Tq_hhY5Y-0HXUjKaS-Kbdepc2HrIQ2jBpma23BvvOTdPfeooCO1iEYlu0O6l63MDQKI6Rp-CKOWSE-ey_NzEqhjH-0m00
-I dont want to program this, just add the following lines to the README.md file that corresponds to this puml file 'aggregator-microservices/etc/aggregator-service.urm.puml'
-pumlid: JOov3SCm301NIGQGs7iRXYPa1g8ayB7NjuiKwGvtmBrbKC-Tq_hhY5Y-0HXUjKaS-Kbdepc2HrIQ2jBpma23BvvOTdPfeooCO1iEYlu0O6l63MDQKI6Rp-CKOWSE-ey_NzEqhjH-0m00
-parent: aggregator-microservices; artifact: information-microservice
-Puml Server ID: LSnB3i8m303Hgy016k-vZN5DQXGxaJ_jzUcMtKXFcgSOZTgvV3oEp1Kl0CUhTScZtXNiD2tPij5Ka54N9ZfyySHjvv1ksy9CTWjGZ3i0UtVkcDCt5V9vFquX3k0a4FjCLqoPzgUjNDig7Jy0
-I dont want to program this, just add the following lines to the README.md file that corresponds to this puml file 'aggregator-microservices/etc/information-microservice.urm.puml'
-pumlid: LSnB3i8m303Hgy016k-vZN5DQXGxaJ_jzUcMtKXFcgSOZTgvV3oEp1Kl0CUhTScZtXNiD2tPij5Ka54N9ZfyySHjvv1ksy9CTWjGZ3i0UtVkcDCt5V9vFquX3k0a4FjCLqoPzgUjNDig7Jy0
-parent: aggregator-microservices; artifact: inventory-microservice
-Puml Server ID: LSpB3G8n303HLg20ZUzqOxnMrYXn8d-oedjovJRIIEyfIYrFJckFAsBw2y3mBbNYodSw6mqDrYWqEaZB6mCDFhZmEDcbwZ4nWaqTEleEm5gDAyQmemlPsCOIOWSE0j6riM7VlrVIUfdPsmy0
-I dont want to program this, just add the following lines to the README.md file that corresponds to this puml file 'aggregator-microservices/etc/inventory-microservice.urm.puml'
-pumlid: LSpB3G8n303HLg20ZUzqOxnMrYXn8d-oedjovJRIIEyfIYrFJckFAsBw2y3mBbNYodSw6mqDrYWqEaZB6mCDFhZmEDcbwZ4nWaqTEleEm5gDAyQmemlPsCOIOWSE0j6riM7VlrVIUfdPsmy0
-parent: bridge; artifact: bridge
-Puml Server ID: BSR14SCm20J0Lf82BFxf1akCJ4R26ZZYzkE7zxLljJgoIVfu7S2A3v7pLRhYo3r3l9u6CPHwJjAH5uETllpZhKbejsqn86v1a-CExQwj2mdgqv8-oyev_W00
-parent: servant; artifact: servant
-Puml Server ID: DSkn4O0m20NGLNG0G-ys63cDbv0SV7HzRUnUy-QYkSOkONKwWU4haV6JZe8pjd2nt1MYIBatAZKU1XjTVFEoYvT3by60c3erzW_qdPiL9CY_KrXB8rfz0G00
-parent: lazy-loading; artifact: lazy-loading
-Puml Server ID: LSXB3W8X303Gg-W1e7jlqu66gIc5zED4JwzRTo_lpjeaEwN9xOpO_W0mlEhWEFD89sjBWpHgMnDOyi90WoU-i7Ho7besHf2fmqJ_0GG_xo8BE-i0YlONDMtMdLE-
-parent: flyweight; artifact: flyweight
-Puml Server ID: HSV94S8m3030Lg20M7-w4OvYAoCh7Xtnq3ty-Eq-MQlaJcdow17JNm26gpIEdkzqidffa4Qfrm2MN1XeSEADsqxEJRU94MJgCD1_W4C-YxZr08hwNqaRPUQGBm00
-parent: mutex; artifact: mutex
-Puml Server ID: 9SR13OCm30NGLSe0n7UsCS62LB69x6zWV2hrdTxKhFRS9Br_3c34GkHybxtXo3L3l9u6CPHwAhMUDuETldpnl4cqtUR1WBW5ASSlf0bvI53_A-bQHcf_0G00
-parent: mediator; artifact: mediator
-Puml Server ID: FSV14SCm20J0Lk82BFxf1akCJKOW3JhizfDNVhkRUktP9AE_Bc2kDr7mKqx5bKSkYJeSuYXr66dFXy517xvvRxBqz7qo8E6BZDSFPDAKCO84zP-IOMMczIy0
-parent: page-object; artifact: page-object
-Puml Server ID: JSV14OGW30NGLjO28FVj9iOCua1Wme-sxnxtzjvMJLeS6ju-9p3NbyZvoQNYZ3sMkWo36hACJhN5ms2dYszEXwvQB4q6r6rHv_K3JIwQndwfW1Jo_npUyupUNW00
-parent: factory-kit; artifact: factory-kit
-Puml Server ID: JST15i8m20N0g-W14lRU1YcsQ4BooCS-RwzBTpDNSscvQKQx7C1SDwBWi-w68--vD6Gur55bTBAM9uE3dlpcikcotSjaGCCNTLu_q8C58pxbPI25_Bzcz3gpjoy0
-parent: property; artifact: property
-Puml Server ID: FSV13OCm30NGLTe1YEziumOBKYMEPN-3s9wUUdlltRJst2Izlmx0OYLolihUSEGdGxnEXIXAdODQpul1Jby-UTaasgwBCI2kGOFZ1pAV9ewR1FMVaZwAvUWF
-parent: dependency-injection; artifact: dependency-injection
-Puml Server ID: RSdB3SCW303GLPe1mFTkunWhSGG6-PEesxS3zFQajubIpyPf_NL6B7y363xra3XpJsUZgS4QbUO0wVbWeC65DvR6BeUMXH5iwZ3GVu36YxMnqgU8NamXKu63_aPD6tNbw5y0
-parent: layers; artifact: layers
-Puml Server ID: BSR13OCm30NGLSe0n7UsCS62L8w9x6yGszD3t-bDpQhc9kdwEO0H2v7pNVQ68zSCyNeQn53gsQbftWns-lB5yoRHTfi70-8Mr3b-8UL7F4XG_otflOpi-W80
-parent: producer-consumer; artifact: producer-consumer
-Puml Server ID: PSjB3iCW303HgxG70Ezx6zTO2HKso9_a-c7VtUX9y-vA8nkdZTSPiVm3O7ZNeyUPttGscXgiKMaAz94t1XhyyCBIsFkXPM44cpe8-WvODbiIMzcdfspXe7-jQL9NodW0
-parent: builder; artifact: builder
-Puml Server ID: DSR94O0m2030LhG0mzzkC64KXs26GzlNZw_TcRLADagJwOWOlW8OFcNdE79B9wkN1ccKUdLWoGS33KwySMdalEioC89C7Jhw5zYIfNrIrFybhPUHNLu0
-parent: specification; artifact: specification
-Puml Server ID: LSX14i8m20NGg-W16lRU1YcsE0d9mCTUNxVkthoxkVJQjQBVJc3bWoZuQeVXh6UbXao7EfhCGTRhOd3Gcp-yxPfs-BOOqF2amVa3vLAnbmd3ffD2_gTLZBPgz2y0
-parent: state; artifact: state
-Puml Server ID: 9SRH3O0m20N0LNG0ox_RO2LQqz867hg-9jxNpKLpZLt2wdG2mrSYuoST1MTiuMAvAqIHSczKQZmCDhhuvcKNBuSkWm4nTMhiNyZ141BaVocifH6jlW00
-parent: reader-writer-lock; artifact: reader-writer-lock
-Puml Server ID: RSZB4S8m303HLg00MtUw4R8cCP5bZpwuVL80jttxx4gIZTFaSKOiVm4OxdhqEFETpaPJWpKgpG5TScEWmGU_M1fxFxGiZ61JXu5-1nXZOolR-gqYaoxWe3-xfeswSiWF
-parent: interpreter; artifact: interpreter
-Puml Server ID: JSf13eCm30NHgz034E-vZGaM62Kcih_BzQ6xxjv8yr6hBJT9RzC1Z5Y8dE-oAuvSCyJhPH13gLSdRNapsEdaBy-RXEus3mR4BQXpl21zVnykFmlgVvVqNaRszW00
-parent: template-method; artifact: template-method
-Puml Server ID: NSZ13SCW30NGLPe1mFTkuu0Lg6n0vZjPlpttzlIEFef6bN1zDM3jDv7paw-E5cTiyJ87P22NQTGr7WOxVVZcL6NtQwJ5WFZOPBn_88WjPKWoGPkL1EN_ShZb5QPV
-parent: feature-toggle; artifact: feature-toggle
-Puml Server ID: NSZ14G8X30NGLhG0oDrk8XjPd12OvCTjNy_UthpxiAPvIBhUJc37WyZvgdtWp6U6U5i6CTIs9WtDYy5ER_vmEIH6jx8P4BUWoV43lOIHBWMhTnKIjB-gwRFkdFe5
-parent: business-delegate; artifact: business-delegate
-Puml Server ID: POl13SCm3CHMQGU8zUysgYCuBcJ5a4x9-l6_Fu84tzsgvYxf-Zg06HyYvxkqZYE_6UBrD8YXr7DGrxmPxFJZYxTTeZVR9WFY5ZGu5j2wkad4wYgD8IIe_xQaZp9pw0C0
-parent: naked-objects; artifact: naked-objects-integtests
-Puml Server ID: LSmn4iCW30NHgoG70FMvZGmQ6ni48tt5ru_RT3kls7VJqgDAM7yTmF8FaV6TzuOZjd2nCXMYo6KEQZrk1XkT_ELKnTkkQJ4Wfaw3_GbIlgIckPrIu2Ge_vBQyziX3izX8wyO_GS0
-I dont want to program this, just add the following lines to the README.md file that corresponds to this puml file 'naked-objects/etc/naked-objects-integtests.urm.puml'
-pumlid: LSmn4iCW30NHgoG70FMvZGmQ6ni48tt5ru_RT3kls7VJqgDAM7yTmF8FaV6TzuOZjd2nCXMYo6KEQZrk1XkT_ELKnTkkQJ4Wfaw3_GbIlgIckPrIu2Ge_vBQyziX3izX8wyO_GS0
-parent: naked-objects; artifact: naked-objects-dom
-Puml Server ID: LSZ94SCW3030Lf82G7zt8mkDZOC4eyDkF_dcjxFlhZIoSTfudH7BDm33fnuzpjpJsMXgi4QbAT17FXXeSE6DfR7tGyl223Pr4FGVGF73hSpzOWe73lgVqgRKDAahPNm1
-I dont want to program this, just add the following lines to the README.md file that corresponds to this puml file 'naked-objects/etc/naked-objects-dom.urm.puml'
-pumlid: LSZ94SCW3030Lf82G7zt8mkDZOC4eyDkF_dcjxFlhZIoSTfudH7BDm33fnuzpjpJsMXgi4QbAT17FXXeSE6DfR7tGyl223Pr4FGVGF73hSpzOWe73lgVqgRKDAahPNm1
-parent: naked-objects; artifact: naked-objects-fixture
-Puml Server ID: LSX15i8W30N0g-W187jlaq9igH1uoO_r-BfrDs_kJKkFAc7zTW3B7qJ6LzuRZjZ2nSfKY2ANEQZrk1XiTFARKnLlkwR5W9Ww3VOVIFabDStjb08dGVcVz6mVX4aE6td5w5y0
-I dont want to program this, just add the following lines to the README.md file that corresponds to this puml file 'naked-objects/etc/naked-objects-fixture.urm.puml'
-pumlid: LSX15i8W30N0g-W187jlaq9igH1uoO_r-BfrDs_kJKkFAc7zTW3B7qJ6LzuRZjZ2nSfKY2ANEQZrk1XiTFARKnLlkwR5W9Ww3VOVIFabDStjb08dGVcVz6mVX4aE6td5w5y0
-parent: model-view-controller; artifact: model-view-controller
-Puml Server ID: ROl13SCm201NQGUm-NSRQgE42h258Lw_wR-_qvtkoTOaEwNBuuoOwmNWkEl1SUOx5taR5cHHsr1WoOs13X-yi7HQV5YP645k2nJN3Q2ZavIBQPVVwqFajXJjVwdfMcUgV040
-parent: proxy; artifact: proxy
-Puml Server ID: 9SR13OCm30NGLM00udktCS62eCI9x6yesrEfx_Jcehd69c5rEe3X7oBZE-q5HwpXOhahH95oRrHgt0msEldYPHClkow30J5rQko_qB3-VKYG_qjXBOrezGK0
-parent: memento; artifact: memento
-Puml Server ID: DSgn4OCm30NGLM00h3xR2AC3SvRiaxx2-g59zugtDgiz3qdlomNC-10vF-Lik7BF4A_388PIXrBh-J3OwUOlRuT4EssR38XRa7Ay81Lz_o11_RkaQvcf_GS0
-parent: decorator; artifact: decorator
-Puml Server ID: HSV14SCm20J0Lk82BFxf1YF6LaP26ZZizfDVVhjRC-bPDRs_Bc35cyZvAMV3bKU6kao36ehCGQtdms2d3z-yLursshuOKBUWmV43LPNfZEcaaFzA-YWhH_y2
-parent: data-mapper; artifact: data-mapper
-Puml Server ID: JShB3OGm303HLg20nFVjnYGM1CN6ycTfVtFSsnjfzY5jPgUqkLqHwXy0mxUU8wuyqidQ8q4IjJqCO-QBWGOtVh5qyd5AKOmW4mT6Nu2-ZiAekapH_hkcSTNa-GC0
-parent: caching; artifact: caching
-Puml Server ID: DSRB4OKm2030LhG0m_rrWyWaE0bc-6ZxpujxsbMKUXwSrfSMCVq7OFYKAj5oJsUZIuCr2bq3fEU3WGOdthWTx59rcnZ1fWu3_GqGKXEjm47VIzeeCqV_0m00
-parent: reactor; artifact: reactor
-Puml Server ID: DSR14OGm20NGLjO23FVj1f7Hx2Ga0nzjVxtuJc-f9YrtJM-V4vZn9NA-or5nvfQXBiEWXYAZKsrvCzZfnnUlkqOzR9qCg5jGvtX2hYmOJWfvNz9xcTdR7m00
-parent: iterator; artifact: iterator
-Puml Server ID: FSV13OGm30NHLg00uljsOu85HeaJsTzB-yjfBwCtgrfjUKXwMovWneV8-IcduiezGxmEWnXA7PsqvSDWfvk_l1qIUjes6H2teCxnWlGDOpW9wdzAUYypU_i1
-parent: callback; artifact: callback
-Puml Server ID: FSVB4S8m30N0Lg20M7UwUL4qYOciUFGXxSE9s-wp6sjjKgwF8tF6YyXnjxtdKMk5E5-MOjdu6jIrRYIStlXWsIJwRij4fhW53SGFn51TmIT9yZ-jVBHPGxy0
-parent: repository; artifact: repository
-Puml Server ID: JSV13OCm30NGLM00udktCS42eyI9xE-YRjyUUtjlLQij3qblomNCU14vF-LKNBbdYDTX44EfevEsV1ZiTFERjqD2Jzic0-8Mr3b-89SvGZ7yGuBwrvBUoypUlW00
-parent: mute-idiom; artifact: mute-idiom
-Puml Server ID: JSf13iCm20NHgxG7iDdtDjH62PKX5luarq-MtSsJvgtUHdR96AyTcEj357pLJR7dDvT4EnpYgEqmqf4NWuD-V7BfidJpCXcGy4N6wmcoX1Jj-lo2ziUQONMcZHi0
-parent: prototype; artifact: prototype
-Puml Server ID: HSV13OCm30NGLM00udktCS62eCInxE-YRj_UUdjlRLfx7fBUbmkmU14vF-Lik7BF4AzJ8OfIvw3Mys6mqyrltWw9Tkfc38XhqE3uWSmd9Zuc9AZ_bVHHB4V_0W00
-parent: step-builder; artifact: step-builder
-Puml Server ID: LOZ93SCm3C1MQGQmzUysYYqaAcJ5q96i7t_x8KXkh4soKvfypeZfNm33fnuSP-xfPEtI88tQhW4i-M2WmGzlB9sS3oqJ8yZKOQ0lWOLPzcJfAoZQtwXfeyuSyW80
-parent: double-checked-locking; artifact: double-checked-locking
-Puml Server ID: TSdH4SCW203GLTe1bFzkGv1J6qGFeLc_MI1_x-wzkv94uJ1vDVUrFm26LwxTMnonsMYgitgcEQ1BNEXeyCKVfiAxLqqBtTbqmy1z0ygCGpXHOpgv99bqTgt0JW-LmqPUCUGF
--- a/_scripts/postPumlsToServer.py
+++ b/_scripts/postPumlsToServer.py
@ -1,67 +0,0 @@
-#
-# The MIT License
-# Copyright (c) 2014 Ilkka Seppälä
-#
-# Permission is hereby granted, free of charge, to any person obtaining a copy
-# of this software and associated documentation files (the "Software"), to deal
-# in the Software without restriction, including without limitation the rights
-# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-# copies of the Software, and to permit persons to whom the Software is
-# furnished to do so, subject to the following conditions:
-#
-# The above copyright notice and this permission notice shall be included in
-# all copies or substantial portions of the Software.
-#
-# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-# THE SOFTWARE.
-#
-
-import requests, glob, re, os
-
-# taken from here: http://stackoverflow.com/a/13641746
-def replace(file, pattern, subst):
-    # Read contents from file as a single string
-    file_handle = open(file, 'r')
-    file_string = file_handle.read()
-    file_handle.close()
-
-    # Use RE package to allow for replacement (also allowing for (multiline) REGEX)
-    file_string = (re.sub(pattern, subst, file_string))
-
-    # Write contents to file.
-    # Using mode 'w' truncates the file.
-    file_handle = open(file, 'w')
-    file_handle.write(file_string)
-    file_handle.close()
-
-# list of all puml files
-fileList = glob.glob('*/etc/*.puml')
-for puml in fileList:
-    pathSplit = puml.split("/")
-    # parent folder
-    parent = pathSplit[0]
-    # individual artifact/project name
-    artifact = pathSplit[2].replace(".urm.puml", "")
-    print "parent: " + parent + "; artifact: " + artifact
-
-    # do a POST to the official plantuml hosting site with a little trick "!includeurl" and raw github content
-    data = {
-        'text': "!includeurl https://raw.githubusercontent.com/iluwatar/java-design-patterns/master/" + puml
-    }
-    r = requests.post('http://plantuml.com/plantuml/uml', data=data)
-    pumlId = r.url.replace("http://plantuml.com/plantuml/uml/", "")
-    
-    # the only thing needed to get a png/svg/ascii from the server back
-    print "Puml Server ID: " + pumlId
-    
-    # add the id so jekyll/liquid can use it
-    if (parent == artifact):
-        replace("./" + parent + "/README.md", "categories:", "pumlid: {}\\ncategories:".format(pumlId))
-    else:
-        print "I dont want to program this, just add the following lines to the README.md file that corresponds to this puml file '" + puml + "'\npumlid: {}".format(pumlId)
-
--- a/abstract-document/README.md
+++ b/abstract-document/README.md
@ -3,18 +3,15 @@ layout: pattern
 title: Abstract Document
 folder: abstract-document
 permalink: /patterns/abstract-document/
-pumlid: PSjB3eCm34NHhPG599vtDyQn85L-ifzX-p3lxEf8Twj3MXGDQvyJMFubChxpKN767gucSq07iinEjSNDOACVNvoAUZr6MWoe3QVE_WRnxZ0Mf38b-hkIGlurX_MyehS7
 categories: Structural
 tags: 
- - Java
- - Difficulty-Intermediate
+ - Extensibility
 ---

 ## Intent
 Achieve flexibility of untyped languages and keep the type-safety 

-![alt text](./etc/abstract-document-base.png "Abstract Document Base")
-
+## Class diagram
 ![alt text](./etc/abstract-document.png "Abstract Document Traits and Domain")


@ -29,4 +26,4 @@ Use the Abstract Document Pattern when
 ## Credits

 * [Wikipedia: Abstract Document Pattern](https://en.wikipedia.org/wiki/Abstract_Document_Pattern)
-* [Martin Fowler: Dealing with properties](http://martinfowler.com/apsupp/properties.pdf)
+* [Martin Fowler: Dealing with properties](http://martinfowler.com/apsupp/properties.pdf)
--- a/abstract-document/etc/abstract-document-base.png
+++ b/abstract-document/etc/abstract-document-base.png
--- a/abstract-document/etc/abstract-document.png
+++ b/abstract-document/etc/abstract-document.png
--- a/abstract-document/etc/abstract-document.ucls
+++ b/abstract-document/etc/abstract-document.ucls
@ -1,91 +1,137 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<class-diagram version="1.1.9" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true" 
-  realizations="true" associations="true" dependencies="false" nesting-relationships="true" router="FAN">  
-  <interface id="1" language="java" name="com.iluwatar.abstractdocument.Document" project="design-patterns" 
-    file="/design-patterns/src/com/iluwatar/abstractdocument/Document.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="341" y="376"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </interface>  
-  <interface id="2" language="java" name="com.iluwatar.abstractdocument.domain.HasModel" project="design-patterns" 
-    file="/design-patterns/src/com/iluwatar/abstractdocument/domain/HasModel.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="81" width="173" x="41" y="194"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </interface>  
-  <interface id="3" language="java" name="com.iluwatar.abstractdocument.domain.HasPrice" project="design-patterns" 
-    file="/design-patterns/src/com/iluwatar/abstractdocument/domain/HasPrice.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="81" width="175" x="254" y="194"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </interface>  
-  <interface id="4" language="java" name="com.iluwatar.abstractdocument.domain.HasParts" project="design-patterns" 
-    file="/design-patterns/src/com/iluwatar/abstractdocument/domain/HasParts.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="81" width="173" x="469" y="194"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </interface>  
-  <class id="5" language="java" name="com.iluwatar.abstractdocument.domain.Car" project="design-patterns" 
-    file="/design-patterns/src/com/iluwatar/abstractdocument/domain/Car.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="99" width="173" x="254" y="37"/>    
+<class-diagram version="1.2.2" icons="true" always-add-relationships="false" generalizations="true" realizations="true" 
+  associations="true" dependencies="false" nesting-relationships="true" router="FAN">  
+  <class id="1" language="java" name="com.iluwatar.abstractdocument.AbstractDocument" project="abstract-document" 
+    file="/abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="659" y="286"/>    
    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
      sort-features="false" accessors="true" visibility="true">      
      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
      <operations public="true" package="true" protected="true" private="true" static="true"/>    
    </display>  
  </class>  
-  <class id="6" language="java" name="com.iluwatar.abstractdocument.domain.Part" project="design-patterns" 
-    file="/design-patterns/src/com/iluwatar/abstractdocument/domain/Part.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="99" width="173" x="41" y="37"/>    
+  <interface id="2" language="java" name="com.iluwatar.abstractdocument.Document" project="abstract-document" 
+    file="/abstract-document/src/main/java/com/iluwatar/abstractdocument/Document.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="562" y="27"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <class id="3" language="java" name="com.iluwatar.abstractdocument.domain.Car" project="abstract-document" 
+    file="/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/Car.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="348" y="737"/>    
    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
      sort-features="false" accessors="true" visibility="true">      
      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
      <operations public="true" package="true" protected="true" private="true" static="true"/>    
    </display>  
  </class>  
-  <realization id="7">    
-    <end type="SOURCE" refId="5"/>    
-    <end type="TARGET" refId="2"/>  
+  <class id="4" language="java" name="com.iluwatar.abstractdocument.domain.Part" project="abstract-document" 
+    file="/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/Part.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="760" y="746"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <interface id="5" language="java" name="com.iluwatar.abstractdocument.domain.HasModel" project="abstract-document" 
+    file="/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasModel.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="355" y="297"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <interface id="6" language="java" name="com.iluwatar.abstractdocument.domain.HasParts" project="abstract-document" 
+    file="/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasParts.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="109" y="297"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <interface id="7" language="java" name="com.iluwatar.abstractdocument.domain.HasPrice" project="abstract-document" 
+    file="/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasPrice.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="1008" y="283"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <interface id="8" language="java" name="com.iluwatar.abstractdocument.domain.HasType" project="abstract-document" 
+    file="/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasType.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="1257" y="277"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <realization id="9">    
+    <end type="SOURCE" refId="4"/>    
+    <end type="TARGET" refId="8"/>  
  </realization>  
-  <realization id="8">    
+  <realization id="10">    
+    <end type="SOURCE" refId="3"/>    
+    <end type="TARGET" refId="7"/>  
+  </realization>  
+  <generalization id="11">    
    <end type="SOURCE" refId="6"/>    
    <end type="TARGET" refId="2"/>  
-  </realization>  
-  <generalization id="9">    
-    <end type="SOURCE" refId="2"/>    
-    <end type="TARGET" refId="1"/>  
  </generalization>  
-  <realization id="10">    
-    <end type="SOURCE" refId="5"/>    
-    <end type="TARGET" refId="3"/>  
+  <realization id="12">    
+    <end type="SOURCE" refId="4"/>    
+    <end type="TARGET" refId="5"/>  
  </realization>  
-  <realization id="11">    
-    <end type="SOURCE" refId="5"/>    
-    <end type="TARGET" refId="4"/>  
+  <realization id="13">    
+    <end type="SOURCE" refId="4"/>    
+    <end type="TARGET" refId="7"/>  
  </realization>  
-  <generalization id="12">    
+  <generalization id="14">    
    <end type="SOURCE" refId="3"/>    
    <end type="TARGET" refId="1"/>  
  </generalization>  
-  <generalization id="13">    
+  <realization id="15">    
+    <end type="SOURCE" refId="3"/>    
+    <end type="TARGET" refId="6"/>  
+  </realization>  
+  <generalization id="16">    
+    <end type="SOURCE" refId="8"/>    
+    <end type="TARGET" refId="2"/>  
+  </generalization>  
+  <generalization id="17">    
+    <end type="SOURCE" refId="7"/>    
+    <end type="TARGET" refId="2"/>  
+  </generalization>  
+  <realization id="18">    
+    <end type="SOURCE" refId="3"/>    
+    <end type="TARGET" refId="5"/>  
+  </realization>  
+  <generalization id="19">    
    <end type="SOURCE" refId="4"/>    
    <end type="TARGET" refId="1"/>  
  </generalization>  
-  <realization id="14">    
-    <end type="SOURCE" refId="6"/>    
-    <end type="TARGET" refId="3"/>  
+  <generalization id="20">    
+    <end type="SOURCE" refId="5"/>    
+    <end type="TARGET" refId="2"/>  
+  </generalization>  
+  <realization id="21">    
+    <end type="SOURCE" refId="1"/>    
+    <end type="TARGET" refId="2"/>  
  </realization>  
  <classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
    sort-features="false" accessors="true" visibility="true">    
--- a/abstract-document/etc/abstract-document.urm.puml
+++ b/abstract-document/etc/abstract-document.urm.puml
@ -1,33 +1,35 @@
@startuml
+package com.iluwatar.abstractdocument.domain.enums {
+  enum Property {
+    + MODEL {static}
+    + PARTS {static}
+    + PRICE {static}
+    + TYPE {static}
+    + valueOf(name : String) : Property {static}
+    + values() : Property[] {static}
+  }
+}
 package com.iluwatar.abstractdocument.domain {
-  class Part {
-    + Part(properties : Map<String, Object>)
-  }
-  interface HasPrice {
-    + PROPERTY : String {static}
-    + getPrice() : Optional<Number>
-  }
-  interface HasParts {
-    + PROPERTY : String {static}
-    + getParts() : Stream<Part>
-  }
  class Car {
    + Car(properties : Map<String, Object>)
  }
+  interface HasModel {
+    + getModel() : Optional<String>
+  }
+  interface HasParts {
+    + getParts() : Stream<Part>
+  }
+  interface HasPrice {
+    + getPrice() : Optional<Number>
+  }
  interface HasType {
-    + PROPERTY : String {static}
    + getType() : Optional<String>
  }
-  interface HasModel {
-    + PROPERTY : String {static}
-    + getModel() : Optional<String>
+  class Part {
+    + Part(properties : Map<String, Object>)
  }
 }
 package com.iluwatar.abstractdocument {
-  class App {
-    + App()
-    + main(args : String[]) {static}
-  }
  abstract class AbstractDocument {
    - properties : Map<String, Object>
    # AbstractDocument(properties : Map<String, Object>)
@ -36,24 +38,28 @@ package com.iluwatar.abstractdocument {
    + put(key : String, value : Object)
    + toString() : String
  }
+  class App {
+    - LOGGER : Logger {static}
+    + App()
+    + main(args : String[]) {static}
+  }
  interface Document {
    + children(String, Function<Map<String, Object>, T>) : Stream<T> {abstract}
    + get(String) : Object {abstract}
    + put(String, Object) {abstract}
  }
 }
-AbstractDocument --+ Map
-Part ..|> HasType 
-Part ..|> HasModel 
-Part ..|> HasPrice 
-Part --|> AbstractDocument 
 AbstractDocument ..|> Document 
-HasPrice --|> Document 
-HasParts --|> Document 
 Car ..|> HasModel 
 Car ..|> HasPrice 
 Car ..|> HasParts 
 Car --|> AbstractDocument 
-HasType --|> Document 
 HasModel --|> Document 
+HasParts --|> Document 
+HasPrice --|> Document 
+HasType --|> Document 
+Part ..|> HasType 
+Part ..|> HasModel 
+Part ..|> HasPrice 
+Part --|> AbstractDocument 
@enduml
--- a/abstract-document/pom.xml
+++ b/abstract-document/pom.xml
@ -1,42 +1,55 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!--
-
-    The MIT License
-    Copyright (c) 2014 Ilkka Seppälä
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-
-->
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <parent>
-        <artifactId>java-design-patterns</artifactId>
-        <groupId>com.iluwatar</groupId>
-        <version>1.13.0</version>
-    </parent>
-    <artifactId>abstract-document</artifactId>
-    <dependencies>
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
-</project>
+<!-- The MIT License Copyright © 2014-2019 Ilkka Seppälä Permission is hereby 
+	granted, free of charge, to any person obtaining a copy of this software 
+	and associated documentation files (the "Software"), to deal in the Software 
+	without restriction, including without limitation the rights to use, copy, 
+	modify, merge, publish, distribute, sublicense, and/or sell copies of the 
+	Software, and to permit persons to whom the Software is furnished to do so, 
+	subject to the following conditions: The above copyright notice and this 
+	permission notice shall be included in all copies or substantial portions 
+	of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY 
+	KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
+	MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN 
+	NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
+	DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
+	ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
+	DEALINGS IN THE SOFTWARE. -->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<artifactId>java-design-patterns</artifactId>
+		<groupId>com.iluwatar</groupId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>abstract-document</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<!-- Maven assembly plugin is invoked with default setting which we have 
+				in parent pom and specifying the class having main method -->
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.abstractdocument.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+</project>
--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/AbstractDocument.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,17 +20,18 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractdocument;

+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.Optional;
 import java.util.function.Function;
 import java.util.stream.Stream;

 /**
- * Abstract implementation of Document interface
+ * Abstract implementation of Document interface.
 */
 public abstract class AbstractDocument implements Document {

@ -54,17 +55,21 @@ public abstract class AbstractDocument implements Document {

  @Override
  public <T> Stream<T> children(String key, Function<Map<String, Object>, T> constructor) {
-    Optional<List<Map<String, Object>>> any = Stream.of(get(key)).filter(el -> el != null)
-        .map(el -> (List<Map<String, Object>>) el).findAny();
-    return any.isPresent() ? any.get().stream().map(constructor) : Stream.empty();
+    return Stream.ofNullable(get(key))
+        .filter(Objects::nonNull)
+        .map(el -> (List<Map<String, Object>>) el)
+        .findAny()
+        .stream()
+        .flatMap(Collection::stream)
+        .map(constructor);
  }

  @Override
  public String toString() {
-    StringBuilder builder = new StringBuilder();
+    var builder = new StringBuilder();
    builder.append(getClass().getName()).append("[");
-    properties.entrySet()
-        .forEach(e -> builder.append("[").append(e.getKey()).append(" : ").append(e.getValue()).append("]"));
+    properties.forEach((key, value) -> builder.append("[").append(key).append(" : ").append(value)
+        .append("]"));
    builder.append("]");
    return builder.toString();
  }
--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/App.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/App.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,64 +20,64 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractdocument;

 import com.iluwatar.abstractdocument.domain.Car;
-import com.iluwatar.abstractdocument.domain.HasModel;
-import com.iluwatar.abstractdocument.domain.HasParts;
-import com.iluwatar.abstractdocument.domain.HasPrice;
-import com.iluwatar.abstractdocument.domain.HasType;
-
-import java.util.Arrays;
-import java.util.HashMap;
+import com.iluwatar.abstractdocument.domain.enums.Property;
+import java.util.List;
 import java.util.Map;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;

 /**
- * The Abstract Document pattern enables handling additional, non-static
- * properties. This pattern uses concept of traits to enable type safety and
- * separate properties of different classes into set of interfaces.
- * <p>
- * <p>
- * In Abstract Document pattern,({@link AbstractDocument}) fully implements
- * {@link Document}) interface. Traits are then defined to enable access to
- * properties in usual, static way.
+ * The Abstract Document pattern enables handling additional, non-static properties. This pattern
+ * uses concept of traits to enable type safety and separate properties of different classes into
+ * set of interfaces.
+ *
+ * <p>In Abstract Document pattern,({@link AbstractDocument}) fully implements {@link Document})
+ * interface. Traits are then defined to enable access to properties in usual, static way.
 */
 public class App {

+  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
+
  /**
-   * Executes the App
+   * Executes the App.
   */
  public App() {
-    System.out.println("Constructing parts and car");
+    LOGGER.info("Constructing parts and car");

-    Map<String, Object> carProperties = new HashMap<>();
-    carProperties.put(HasModel.PROPERTY, "300SL");
-    carProperties.put(HasPrice.PROPERTY, 10000L);
+    var wheelProperties = Map.of(
+        Property.TYPE.toString(), "wheel",
+        Property.MODEL.toString(), "15C",
+        Property.PRICE.toString(), 100L);

-    Map<String, Object> wheelProperties = new HashMap<>();
-    wheelProperties.put(HasType.PROPERTY, "wheel");
-    wheelProperties.put(HasModel.PROPERTY, "15C");
-    wheelProperties.put(HasPrice.PROPERTY, 100L);
+    var doorProperties = Map.of(
+        Property.TYPE.toString(), "door",
+        Property.MODEL.toString(), "Lambo",
+        Property.PRICE.toString(), 300L);

-    Map<String, Object> doorProperties = new HashMap<>();
-    doorProperties.put(HasType.PROPERTY, "door");
-    doorProperties.put(HasModel.PROPERTY, "Lambo");
-    doorProperties.put(HasPrice.PROPERTY, 300L);
+    var carProperties = Map.of(
+        Property.MODEL.toString(), "300SL",
+        Property.PRICE.toString(), 10000L,
+        Property.PARTS.toString(), List.of(wheelProperties, doorProperties));

-    carProperties.put(HasParts.PROPERTY, Arrays.asList(wheelProperties, doorProperties));
+    var car = new Car(carProperties);

-    Car car = new Car(carProperties);
-
-    System.out.println("Here is our car:");
-    System.out.println("-> model: " + car.getModel().get());
-    System.out.println("-> price: " + car.getPrice().get());
-    System.out.println("-> parts: ");
-    car.getParts().forEach(p -> System.out
-        .println("\t" + p.getType().get() + "/" + p.getModel().get() + "/" + p.getPrice().get()));
+    LOGGER.info("Here is our car:");
+    LOGGER.info("-> model: {}", car.getModel().orElseThrow());
+    LOGGER.info("-> price: {}", car.getPrice().orElseThrow());
+    LOGGER.info("-> parts: ");
+    car.getParts().forEach(p -> LOGGER.info("\t{}/{}/{}",
+        p.getType().orElse(null),
+        p.getModel().orElse(null),
+        p.getPrice().orElse(null))
+    );
  }

  /**
-   * Program entry point
+   * Program entry point.
   *
   * @param args command line args
   */
--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/Document.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/Document.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,6 +20,7 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractdocument;

 import java.util.Map;
@ -27,12 +28,12 @@ import java.util.function.Function;
 import java.util.stream.Stream;

 /**
- * Document interface
+ * Document interface.
 */
 public interface Document {

  /**
-   * Puts the value related to the key
+   * Puts the value related to the key.
   *
   * @param key   element key
   * @param value element value
@ -41,7 +42,7 @@ public interface Document {
  Void put(String key, Object value);

  /**
-   * Gets the value for the key
+   * Gets the value for the key.
   *
   * @param key element key
   * @return value or null
@ -49,7 +50,7 @@ public interface Document {
  Object get(String key);

  /**
-   * Gets the stream of child documents
+   * Gets the stream of child documents.
   *
   * @param key         element key
   * @param constructor constructor of child class
--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/Car.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/Car.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,14 +20,14 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractdocument.domain;

+import com.iluwatar.abstractdocument.AbstractDocument;
 import java.util.Map;

-import com.iluwatar.abstractdocument.AbstractDocument;
-
 /**
- * Car entity
+ * Car entity.
 */
 public class Car extends AbstractDocument implements HasModel, HasPrice, HasParts {

--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasModel.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasModel.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,21 +20,20 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractdocument.domain;

+import com.iluwatar.abstractdocument.Document;
+import com.iluwatar.abstractdocument.domain.enums.Property;
 import java.util.Optional;

-import com.iluwatar.abstractdocument.Document;
-
 /**
- * HasModel trait for static access to 'model' property
+ * HasModel trait for static access to 'model' property.
 */
 public interface HasModel extends Document {

-  String PROPERTY = "model";
-
  default Optional<String> getModel() {
-    return Optional.ofNullable((String) get(PROPERTY));
+    return Optional.ofNullable((String) get(Property.MODEL.toString()));
  }

 }
--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasParts.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasParts.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,21 +20,21 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractdocument.domain;

+import com.iluwatar.abstractdocument.Document;
+import com.iluwatar.abstractdocument.domain.enums.Property;
 import java.util.stream.Stream;

-import com.iluwatar.abstractdocument.Document;
-
 /**
- * HasParts trait for static access to 'parts' property
+ * HasParts trait for static access to 'parts' property.
 */
 public interface HasParts extends Document {

-  String PROPERTY = "parts";

  default Stream<Part> getParts() {
-    return children(PROPERTY, Part::new);
+    return children(Property.PARTS.toString(), Part::new);
  }

 }
--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasPrice.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasPrice.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,21 +20,21 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractdocument.domain;

+import com.iluwatar.abstractdocument.Document;
+import com.iluwatar.abstractdocument.domain.enums.Property;
 import java.util.Optional;

-import com.iluwatar.abstractdocument.Document;
-
 /**
- * HasPrice trait for static access to 'price' property
+ * HasPrice trait for static access to 'price' property.
 */
 public interface HasPrice extends Document {

-  String PROPERTY = "price";

  default Optional<Number> getPrice() {
-    return Optional.ofNullable((Number) get(PROPERTY));
+    return Optional.ofNullable((Number) get(Property.PRICE.toString()));
  }

 }
--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasType.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasType.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,21 +20,21 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractdocument.domain;

 import com.iluwatar.abstractdocument.Document;
-
+import com.iluwatar.abstractdocument.domain.enums.Property;
 import java.util.Optional;

 /**
- * HasType trait for static access to 'type' property
+ * HasType trait for static access to 'type' property.
 */
 public interface HasType extends Document {

-  String PROPERTY = "type";

  default Optional<String> getType() {
-    return Optional.ofNullable((String) get(PROPERTY));
+    return Optional.ofNullable((String) get(Property.TYPE.toString()));
  }

 }
--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/Part.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/Part.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,14 +20,14 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractdocument.domain;

+import com.iluwatar.abstractdocument.AbstractDocument;
 import java.util.Map;

-import com.iluwatar.abstractdocument.AbstractDocument;
-
 /**
- * Part entity
+ * Part entity.
 */
 public class Part extends AbstractDocument implements HasType, HasModel, HasPrice {

--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/enums/Property.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/enums/Property.java
@ -0,0 +1,32 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.abstractdocument.domain.enums;
+
+/**
+ * Enum To Describe Property type.
+ */
+public enum Property {
+
+  PARTS, TYPE, PRICE, MODEL
+}
--- a/abstract-document/src/main/java/com/iluwatar/abstractdocument/module-info.java
+++ b/abstract-document/src/main/java/com/iluwatar/abstractdocument/module-info.java
@ -0,0 +1,26 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+module com.iluwatar.abstractdocument {
+	requires org.slf4j;
+}
--- a/abstract-document/src/test/java/com/iluwatar/abstractdocument/AbstractDocumentTest.java
+++ b/abstract-document/src/test/java/com/iluwatar/abstractdocument/AbstractDocumentTest.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,18 +20,17 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractdocument;

-import org.junit.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;

-import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.stream.Stream;
-
-import static junit.framework.TestCase.assertEquals;
-import static junit.framework.TestCase.assertNotNull;
+import org.junit.jupiter.api.Test;

 /**
 * AbstractDocument test class
@ -58,31 +57,28 @@ public class AbstractDocumentTest {

  @Test
  public void shouldRetrieveChildren() {
-    Map<String, Object> child1 = new HashMap<>();
-    Map<String, Object> child2 = new HashMap<>();
-    List<Map<String, Object>> children = Arrays.asList(child1, child2);
+    var children = List.of(Map.of(), Map.of());

    document.put(KEY, children);

-    Stream<DocumentImplementation> childrenStream = document.children(KEY, DocumentImplementation::new);
+    var childrenStream = document.children(KEY, DocumentImplementation::new);
    assertNotNull(children);
    assertEquals(2, childrenStream.count());
  }

  @Test
  public void shouldRetrieveEmptyStreamForNonExistingChildren() {
-    Stream<DocumentImplementation> children = document.children(KEY, DocumentImplementation::new);
+    var children = document.children(KEY, DocumentImplementation::new);
    assertNotNull(children);
    assertEquals(0, children.count());
  }

  @Test
  public void shouldIncludePropsInToString() {
-    Map<String, Object> props = new HashMap<>();
-    props.put(KEY, VALUE);
-    DocumentImplementation document = new DocumentImplementation(props);
-    assertNotNull(document.toString().contains(KEY));
-    assertNotNull(document.toString().contains(VALUE));
+    var props = Map.of(KEY, (Object) VALUE);
+    var document = new DocumentImplementation(props);
+    assertTrue(document.toString().contains(KEY));
+    assertTrue(document.toString().contains(VALUE));
  }

 }
--- a/abstract-document/src/test/java/com/iluwatar/abstractdocument/AppTest.java
+++ b/abstract-document/src/test/java/com/iluwatar/abstractdocument/AppTest.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,9 +20,10 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractdocument;

-import org.junit.Test;
+import org.junit.jupiter.api.Test;

 /**
 * Simple App test
--- a/abstract-document/src/test/java/com/iluwatar/abstractdocument/DomainTest.java
+++ b/abstract-document/src/test/java/com/iluwatar/abstractdocument/DomainTest.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,21 +20,17 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractdocument;

+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 import com.iluwatar.abstractdocument.domain.Car;
-import com.iluwatar.abstractdocument.domain.HasModel;
-import com.iluwatar.abstractdocument.domain.HasParts;
-import com.iluwatar.abstractdocument.domain.HasPrice;
-import com.iluwatar.abstractdocument.domain.HasType;
 import com.iluwatar.abstractdocument.domain.Part;
-import org.junit.Test;
-
-import java.util.Arrays;
-import java.util.HashMap;
+import com.iluwatar.abstractdocument.domain.enums.Property;
+import java.util.List;
 import java.util.Map;
-
-import static junit.framework.TestCase.assertEquals;
+import org.junit.jupiter.api.Test;

 /**
 * Test for Part and Car
@ -50,27 +46,27 @@ public class DomainTest {

  @Test
  public void shouldConstructPart() {
-    Map<String, Object> partProperties = new HashMap<>();
-    partProperties.put(HasType.PROPERTY, TEST_PART_TYPE);
-    partProperties.put(HasModel.PROPERTY, TEST_PART_MODEL);
-    partProperties.put(HasPrice.PROPERTY, TEST_PART_PRICE);
-    Part part = new Part(partProperties);
-
-    assertEquals(TEST_PART_TYPE, part.getType().get());
-    assertEquals(TEST_PART_MODEL, part.getModel().get());
-    assertEquals(TEST_PART_PRICE, part.getPrice().get());
+    var partProperties = Map.of(
+        Property.TYPE.toString(), TEST_PART_TYPE,
+        Property.MODEL.toString(), TEST_PART_MODEL,
+        Property.PRICE.toString(), (Object) TEST_PART_PRICE
+    );
+    var part = new Part(partProperties);
+    assertEquals(TEST_PART_TYPE, part.getType().orElseThrow());
+    assertEquals(TEST_PART_MODEL, part.getModel().orElseThrow());
+    assertEquals(TEST_PART_PRICE, part.getPrice().orElseThrow());
  }

  @Test
  public void shouldConstructCar() {
-    Map<String, Object> carProperties = new HashMap<>();
-    carProperties.put(HasModel.PROPERTY, TEST_CAR_MODEL);
-    carProperties.put(HasPrice.PROPERTY, TEST_CAR_PRICE);
-    carProperties.put(HasParts.PROPERTY, Arrays.asList(new HashMap<>(), new HashMap<>()));
-    Car car = new Car(carProperties);
-
-    assertEquals(TEST_CAR_MODEL, car.getModel().get());
-    assertEquals(TEST_CAR_PRICE, car.getPrice().get());
+    var carProperties = Map.of(
+        Property.MODEL.toString(), TEST_CAR_MODEL,
+        Property.PRICE.toString(), TEST_CAR_PRICE,
+        Property.PARTS.toString(), List.of(Map.of(), Map.of())
+    );
+    var car = new Car(carProperties);
+    assertEquals(TEST_CAR_MODEL, car.getModel().orElseThrow());
+    assertEquals(TEST_CAR_PRICE, car.getPrice().orElseThrow());
    assertEquals(2, car.getParts().count());
  }

--- a/abstract-factory/README.md
+++ b/abstract-factory/README.md
@ -3,12 +3,9 @@ layout: pattern
 title: Abstract Factory
 folder: abstract-factory
 permalink: /patterns/abstract-factory/
-pumlid: PSZB3OD034NHLa81Czwd6sCC39gVxEUWT1_ssLmTtQLqgR5fM7sTmFGtaV6TZu8prd0r6HtQaMKqAZLk1XjT_E6qgPUZfyc0MdTgx0-8LuUn8ErFXdr98NypXxKyezKV
 categories: Creational
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+ - Gang of Four
 ---

 ## Also known as
@ -18,7 +15,149 @@ Kit
 Provide an interface for creating families of related or dependent
 objects without specifying their concrete classes.

-![alt text](./etc/abstract-factory_1.png "Abstract Factory")
+## Explanation
+Real world example
+
+> To create a kingdom we need objects with common theme. Elven kingdom needs an Elven king, Elven castle and Elven army whereas Orcish kingdom needs an Orcish king, Orcish castle and Orcish army. There is a dependency between the objects in the kingdom.
+
+In plain words
+
+> A factory of factories; a factory that groups the individual but related/dependent factories together without specifying their concrete classes.
+
+Wikipedia says
+
+> The abstract factory pattern provides a way to encapsulate a group of individual factories that have a common theme without specifying their concrete classes
+
+**Programmatic Example**
+
+Translating the kingdom example above. First of all we have some interfaces and implementation for the objects in the kingdom
+
+```java
+public interface Castle {
+  String getDescription();
+}
+public interface King {
+  String getDescription();
+}
+public interface Army {
+  String getDescription();
+}
+
+// Elven implementations ->
+public class ElfCastle implements Castle {
+  static final String DESCRIPTION = "This is the Elven castle!";
+  @Override
+  public String getDescription() {
+    return DESCRIPTION;
+  }
+}
+public class ElfKing implements King {
+  static final String DESCRIPTION = "This is the Elven king!";
+  @Override
+  public String getDescription() {
+    return DESCRIPTION;
+  }
+}
+public class ElfArmy implements Army {
+  static final String DESCRIPTION = "This is the Elven Army!";
+  @Override
+  public String getDescription() {
+    return DESCRIPTION;
+  }
+}
+
+// Orcish implementations similarly...
+
+```
+
+Then we have the abstraction and implementations for the kingdom factory
+
+```java
+public interface KingdomFactory {
+  Castle createCastle();
+  King createKing();
+  Army createArmy();
+}
+
+public class ElfKingdomFactory implements KingdomFactory {
+  public Castle createCastle() {
+    return new ElfCastle();
+  }
+  public King createKing() {
+    return new ElfKing();
+  }
+  public Army createArmy() {
+    return new ElfArmy();
+  }
+}
+
+public class OrcKingdomFactory implements KingdomFactory {
+  public Castle createCastle() {
+    return new OrcCastle();
+  }
+  public King createKing() {
+    return new OrcKing();
+  }
+  public Army createArmy() {
+    return new OrcArmy();
+  }
+}
+```
+
+Now we have our abstract factory that lets us make family of related objects i.e. Elven kingdom factory creates Elven castle, king and army etc.
+
+```java
+var factory = new ElfKingdomFactory();
+var castle = factory.createCastle();
+var king = factory.createKing();
+var army = factory.createArmy();
+
+castle.getDescription();  // Output: This is the Elven castle!
+king.getDescription(); // Output: This is the Elven king!
+army.getDescription(); // Output: This is the Elven Army!
+```
+
+Now, we can design a factory for our different kingdom factories. In this example, we created FactoryMaker, responsible for returning an instance of either ElfKingdomFactory or OrcKingdomFactory.  
+The client can use FactoryMaker to create the desired concrete factory which, in turn, will produce different concrete objects (Army, King, Castle).  
+In this example, we also used an enum to parameterize which type of kingdom factory the client will ask for.
+
+```java
+public static class FactoryMaker {
+
+  public enum KingdomType {
+    ELF, ORC
+  }
+
+  public static KingdomFactory makeFactory(KingdomType type) {
+    switch (type) {
+      case ELF:
+        return new ElfKingdomFactory();
+      case ORC:
+        return new OrcKingdomFactory();
+      default:
+        throw new IllegalArgumentException("KingdomType not supported.");
+    }
+  }
+}
+
+public static void main(String[] args) {
+  var app = new App();
+
+  LOGGER.info("Elf Kingdom");
+  app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF));
+  LOGGER.info(app.getArmy().getDescription());
+  LOGGER.info(app.getCastle().getDescription());
+  LOGGER.info(app.getKing().getDescription());
+
+  LOGGER.info("Orc Kingdom");
+  app.createKingdom(FactoryMaker.makeFactory(KingdomType.ORC));
+  -- similar use of the orc factory
+}
+```
+
+## Class diagram
+![alt text](./etc/abstract-factory.urm.png "Abstract Factory class diagram")
+

 ## Applicability
 Use the Abstract Factory pattern when
@ -27,6 +166,29 @@ Use the Abstract Factory pattern when
 * a system should be configured with one of multiple families of products
 * a family of related product objects is designed to be used together, and you need to enforce this constraint
 * you want to provide a class library of products, and you want to reveal just their interfaces, not their implementations
+* the lifetime of the dependency is conceptually shorter than the lifetime of the consumer.
+*	you need a run-time value to construct a particular dependency
+*	you want to decide which product to call from a family at runtime.
+*	you need to supply one or more parameters only known at run-time before you can resolve a dependency.
+* when you need consistency among products
+* you don’t want to change existing code when adding new products or families of products to the program.
+
+## Use Cases:	
+
+*	Selecting to call the appropriate implementation of FileSystemAcmeService or DatabaseAcmeService or NetworkAcmeService at runtime.
+*	Unit test case writing becomes much easier
+* UI tools for different OS
+
+## Consequences:
+
+*	Dependency injection in java hides the service class dependencies that can lead to runtime errors that would have been caught at compile time.
+* While the pattern is great when creating predefined objects, adding the new ones might be challenging.
+* The code may become more complicated than it should be, since a lot of new interfaces and classes are introduced along with the pattern.
+
+
+## Tutorial
+* [Abstract Factory Pattern Tutorial](https://www.journaldev.com/1418/abstract-factory-design-pattern-in-java) 
+

 ## Real world examples

@ -36,4 +198,5 @@ Use the Abstract Factory pattern when

 ## Credits

-* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)
+* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59)
+* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b)
--- a/abstract-factory/etc/abstract-factory.png
+++ b/abstract-factory/etc/abstract-factory.png
--- a/abstract-factory/etc/abstract-factory.ucls
+++ b/abstract-factory/etc/abstract-factory.ucls
@ -1,159 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<class-diagram version="1.1.8" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true" 
-  realizations="true" associations="true" dependencies="false" nesting-relationships="true">  
-  <interface id="1" language="java" name="com.iluwatar.abstractfactory.Army" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/Army.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="70" width="161" x="1407" y="300"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </interface>  
-  <interface id="2" language="java" name="com.iluwatar.abstractfactory.KingdomFactory" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/KingdomFactory.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="124" width="161" x="1001" y="300"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </interface>  
-  <class id="3" language="java" name="com.iluwatar.abstractfactory.ElfCastle" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfCastle.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="106" width="161" x="96" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <class id="4" language="java" name="com.iluwatar.abstractfactory.ElfKingdomFactory" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKingdomFactory.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="142" width="161" x="900" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <class id="5" language="java" name="com.iluwatar.abstractfactory.ElfKing" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKing.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="106" width="161" x="498" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <interface id="6" language="java" name="com.iluwatar.abstractfactory.King" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/King.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="70" width="161" x="599" y="300"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </interface>  
-  <class id="7" language="java" name="com.iluwatar.abstractfactory.OrcCastle" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcCastle.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="106" width="161" x="297" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <class id="8" language="java" name="com.iluwatar.abstractfactory.OrcKing" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKing.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="106" width="161" x="699" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <class id="9" language="java" name="com.iluwatar.abstractfactory.ElfArmy" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfArmy.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="106" width="161" x="1306" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <class id="10" language="java" name="com.iluwatar.abstractfactory.OrcArmy" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcArmy.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="106" width="161" x="1507" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <interface id="11" language="java" name="com.iluwatar.abstractfactory.Castle" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/Castle.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="70" width="161" x="197" y="300"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </interface>  
-  <class id="12" language="java" name="com.iluwatar.abstractfactory.OrcKingdomFactory" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKingdomFactory.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="142" width="165" x="1101" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <realization id="13">    
-    <end type="SOURCE" refId="4"/>    
-    <end type="TARGET" refId="2"/>  
-  </realization>  
-  <realization id="14">    
-    <end type="SOURCE" refId="7"/>    
-    <end type="TARGET" refId="11"/>  
-  </realization>  
-  <realization id="15">    
-    <end type="SOURCE" refId="8"/>    
-    <end type="TARGET" refId="6"/>  
-  </realization>  
-  <realization id="16">    
-    <end type="SOURCE" refId="3"/>    
-    <end type="TARGET" refId="11"/>  
-  </realization>  
-  <realization id="17">    
-    <end type="SOURCE" refId="10"/>    
-    <end type="TARGET" refId="1"/>  
-  </realization>  
-  <realization id="18">    
-    <end type="SOURCE" refId="12"/>    
-    <end type="TARGET" refId="2"/>  
-  </realization>  
-  <realization id="19">    
-    <end type="SOURCE" refId="5"/>    
-    <end type="TARGET" refId="6"/>  
-  </realization>  
-  <realization id="20">    
-    <end type="SOURCE" refId="9"/>    
-    <end type="TARGET" refId="1"/>  
-  </realization>  
-  <classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-    sort-features="false" accessors="true" visibility="true">    
-    <attributes public="true" package="true" protected="true" private="true" static="true"/>    
-    <operations public="true" package="true" protected="true" private="true" static="true"/>  
-  </classifier-display>  
-  <association-display labels="true" multiplicity="true"/>
-</class-diagram>
--- a/abstract-factory/etc/abstract-factory.urm.png
+++ b/abstract-factory/etc/abstract-factory.urm.png
--- a/abstract-factory/etc/abstract-factory.urm.puml
+++ b/abstract-factory/etc/abstract-factory.urm.puml
@ -1,6 +1,7 @@
@startuml
 package com.iluwatar.abstractfactory {
  class App {
+    - LOGGER : Logger {static}
    - army : Army
    - castle : Castle
    - king : King
@ -17,72 +18,84 @@ package com.iluwatar.abstractfactory {
    - setCastle(castle : Castle)
    - setKing(king : King)
  }
-  class OrcKingdomFactory {
-    + OrcKingdomFactory()
-    + createArmy() : Army
-    + createCastle() : Castle
-    + createKing() : King
+  class FactoryMaker {
+    + FactoryMaker()
+    + makeFactory(type : KingdomType) : KingdomFactory {static}
  }
-  class ElfCastle {
-    ~ DESCRIPTION : String {static}
-    + ElfCastle()
-    + getDescription() : String
+  enum KingdomType {
+    + ELF {static}
+    + ORC {static}
+    + valueOf(name : String) : KingdomType {static}
+    + values() : KingdomType[] {static}
  }
-  class OrcCastle {
-    ~ DESCRIPTION : String {static}
-    + OrcCastle()
-    + getDescription() : String
+  interface Army {
+    + getDescription() : String {abstract}
  }
-  interface KingdomFactory {
-    + createArmy() : Army {abstract}
-    + createCastle() : Castle {abstract}
-    + createKing() : King {abstract}
-  }
-  class ElfKing {
-    ~ DESCRIPTION : String {static}
-    + ElfKing()
-    + getDescription() : String
+  interface Castle {
+    + getDescription() : String {abstract}
  }
  class ElfArmy {
    ~ DESCRIPTION : String {static}
    + ElfArmy()
    + getDescription() : String
  }
-  interface Castle {
-    + getDescription() : String {abstract}
-  }
-  interface Army {
-    + getDescription() : String {abstract}
-  }
-  class OrcKing {
+  class ElfCastle {
    ~ DESCRIPTION : String {static}
-    + OrcKing()
+    + ElfCastle()
    + getDescription() : String
  }
-  class OrcArmy {
+  class ElfKing {
    ~ DESCRIPTION : String {static}
-    + OrcArmy()
+    + ElfKing()
    + getDescription() : String
  }
-  interface King {
-    + getDescription() : String {abstract}
-  }
  class ElfKingdomFactory {
    + ElfKingdomFactory()
    + createArmy() : Army
    + createCastle() : Castle
    + createKing() : King
  }
+  interface King {
+    + getDescription() : String {abstract}
+  }
+  interface KingdomFactory {
+    + createArmy() : Army {abstract}
+    + createCastle() : Castle {abstract}
+    + createKing() : King {abstract}
+  }
+  class OrcArmy {
+    ~ DESCRIPTION : String {static}
+    + OrcArmy()
+    + getDescription() : String
+  }
+  class OrcCastle {
+    ~ DESCRIPTION : String {static}
+    + OrcCastle()
+    + getDescription() : String
+  }
+  class OrcKing {
+    ~ DESCRIPTION : String {static}
+    + OrcKing()
+    + getDescription() : String
+  }
+  class OrcKingdomFactory {
+    + OrcKingdomFactory()
+    + createArmy() : Army
+    + createCastle() : Castle
+    + createKing() : King
+  }
 }
+KingdomType ..+ FactoryMaker
 App -->  "-castle" Castle
+FactoryMaker ..+ App
 App -->  "-king" King
 App -->  "-army" Army
-OrcKingdomFactory ..|> KingdomFactory 
-ElfCastle ..|> Castle 
-OrcCastle ..|> Castle 
-ElfKing ..|> King 
 ElfArmy ..|> Army 
-OrcKing ..|> King 
-OrcArmy ..|> Army 
+ElfCastle ..|> Castle 
+ElfKing ..|> King 
 ElfKingdomFactory ..|> KingdomFactory 
+OrcArmy ..|> Army 
+OrcCastle ..|> Castle 
+OrcKing ..|> King 
+OrcKingdomFactory ..|> KingdomFactory 
@enduml
--- a/abstract-factory/etc/abstract-factory_1.png
+++ b/abstract-factory/etc/abstract-factory_1.png
--- a/abstract-factory/pom.xml
+++ b/abstract-factory/pom.xml
@ -1,42 +1,56 @@
 <?xml version="1.0"?>
-<!--
-
-    The MIT License
-    Copyright (c) 2014 Ilkka Seppälä
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-
-->
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-  <modelVersion>4.0.0</modelVersion>
-  <parent>
-    <groupId>com.iluwatar</groupId>
-    <artifactId>java-design-patterns</artifactId>
-    <version>1.13.0</version>
-  </parent>
-  <artifactId>abstract-factory</artifactId>
-  <dependencies>
-    <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
+<!-- The MIT License Copyright © 2014-2019 Ilkka Seppälä Permission is hereby 
+	granted, free of charge, to any person obtaining a copy of this software 
+	and associated documentation files (the "Software"), to deal in the Software 
+	without restriction, including without limitation the rights to use, copy, 
+	modify, merge, publish, distribute, sublicense, and/or sell copies of the 
+	Software, and to permit persons to whom the Software is furnished to do so, 
+	subject to the following conditions: The above copyright notice and this 
+	permission notice shall be included in all copies or substantial portions 
+	of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY 
+	KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
+	MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN 
+	NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
+	DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
+	ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
+	DEALINGS IN THE SOFTWARE. -->
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>com.iluwatar</groupId>
+		<artifactId>java-design-patterns</artifactId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>abstract-factory</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<!-- Maven assembly plugin is invoked with default setting which we have 
+				in parent pom and specifying the class having main method -->
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.abstractfactory.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>
--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/App.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/App.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,31 +20,37 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

+import com.iluwatar.abstractfactory.App.FactoryMaker.KingdomType;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 /**
- * 
- * The Abstract Factory pattern provides a way to encapsulate a group of individual factories that have a common theme
- * without specifying their concrete classes. In normal usage, the client software creates a concrete implementation of
- * the abstract factory and then uses the generic interface of the factory to create the concrete objects that are part
- * of the theme. The client does not know (or care) which concrete objects it gets from each of these internal
- * factories, since it uses only the generic interfaces of their products. This pattern separates the details of
- * implementation of a set of objects from their general usage and relies on object composition, as object creation is
- * implemented in methods exposed in the factory interface.
- * <p>
- * The essence of the Abstract Factory pattern is a factory interface ({@link KingdomFactory}) and its implementations (
- * {@link ElfKingdomFactory}, {@link OrcKingdomFactory}). The example uses both concrete implementations to create a
- * king, a castle and an army.
- * 
+ * The Abstract Factory pattern provides a way to encapsulate a group of individual factories that
+ * have a common theme without specifying their concrete classes. In normal usage, the client
+ * software creates a concrete implementation of the abstract factory and then uses the generic
+ * interface of the factory to create the concrete objects that are part of the theme. The client
+ * does not know (or care) which concrete objects it gets from each of these internal factories,
+ * since it uses only the generic interfaces of their products. This pattern separates the details
+ * of implementation of a set of objects from their general usage and relies on object composition,
+ * as object creation is implemented in methods exposed in the factory interface.
+ *
+ * <p>The essence of the Abstract Factory pattern is a factory interface ({@link KingdomFactory})
+ * and its implementations ( {@link ElfKingdomFactory}, {@link OrcKingdomFactory}). The example uses
+ * both concrete implementations to create a king, a castle and an army.
 */
 public class App {

+  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
+
  private King king;
  private Castle castle;
  private Army army;

  /**
-   * Creates kingdom
+   * Creates kingdom.
   */
  public void createKingdom(final KingdomFactory factory) {
    setKing(factory.createKing());
@ -63,7 +69,7 @@ public class App {
  private void setKing(final King king) {
    this.king = king;
  }
-  
+
  Castle getCastle(final KingdomFactory factory) {
    return factory.createCastle();
  }
@ -75,7 +81,7 @@ public class App {
  private void setCastle(final Castle castle) {
    this.castle = castle;
  }
-  
+
  Army getArmy(final KingdomFactory factory) {
    return factory.createArmy();
  }
@ -87,29 +93,53 @@ public class App {
  private void setArmy(final Army army) {
    this.army = army;
  }
-  
+
  /**
-   * Program entry point
-   * 
-   * @param args
-   *          command line args
+   * The factory of kingdom factories.
+   */
+  public static class FactoryMaker {
+
+    /**
+     * Enumeration for the different types of Kingdoms.
+     */
+    public enum KingdomType {
+      ELF, ORC
+    }
+
+    /**
+     * The factory method to create KingdomFactory concrete objects.
+     */
+    public static KingdomFactory makeFactory(KingdomType type) {
+      switch (type) {
+        case ELF:
+          return new ElfKingdomFactory();
+        case ORC:
+          return new OrcKingdomFactory();
+        default:
+          throw new IllegalArgumentException("KingdomType not supported.");
+      }
+    }
+  }
+
+  /**
+   * Program entry point.
+   *
+   * @param args command line args
   */
  public static void main(String[] args) {

-    App app = new App();
+    var app = new App();

-    System.out.println("Elf Kingdom");
-    app.createKingdom(new ElfKingdomFactory());
-    System.out.println(app.getArmy().getDescription());
-    System.out.println(app.getCastle().getDescription());
-    System.out.println(app.getKing().getDescription());
-
-    System.out.println("\nOrc Kingdom");
-    app.createKingdom(new OrcKingdomFactory());
-    System.out.println(app.getArmy().getDescription());
-    System.out.println(app.getCastle().getDescription());
-    System.out.println(app.getKing().getDescription());
+    LOGGER.info("Elf Kingdom");
+    app.createKingdom(FactoryMaker.makeFactory(KingdomType.ELF));
+    LOGGER.info(app.getArmy().getDescription());
+    LOGGER.info(app.getCastle().getDescription());
+    LOGGER.info(app.getKing().getDescription());

+    LOGGER.info("Orc Kingdom");
+    app.createKingdom(FactoryMaker.makeFactory(KingdomType.ORC));
+    LOGGER.info(app.getArmy().getDescription());
+    LOGGER.info(app.getCastle().getDescription());
+    LOGGER.info(app.getKing().getDescription());
  }
-
-}
+}
--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/Army.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/Army.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,12 +20,11 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

 /**
- * 
- * Army interface
- *
+ * Army interface.
 */
 public interface Army {

--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/Castle.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/Castle.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,12 +20,11 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

 /**
- * 
- * Castle interface
- *
+ * Castle interface.
 */
 public interface Castle {

--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfArmy.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfArmy.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,12 +20,11 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

 /**
- * 
- * ElfArmy
- *
+ * ElfArmy.
 */
 public class ElfArmy implements Army {

--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfCastle.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfCastle.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,12 +20,11 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

 /**
- * 
- * ElfCastle
- *
+ * ElfCastle.
 */
 public class ElfCastle implements Castle {

--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKing.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKing.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,12 +20,11 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

 /**
- * 
- * ElfKing
- *
+ * ElfKing.
 */
 public class ElfKing implements King {

--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKingdomFactory.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKingdomFactory.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,23 +20,25 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

 /**
- * 
 * ElfKingdomFactory concrete factory.
- * 
 */
 public class ElfKingdomFactory implements KingdomFactory {

+  @Override
  public Castle createCastle() {
    return new ElfCastle();
  }

+  @Override
  public King createKing() {
    return new ElfKing();
  }

+  @Override
  public Army createArmy() {
    return new ElfArmy();
  }
--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/King.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/King.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,12 +20,11 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

 /**
- * 
- * King interface
- *
+ * King interface.
 */
 public interface King {

--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/KingdomFactory.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/KingdomFactory.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,12 +20,11 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

 /**
- * 
 * KingdomFactory factory interface.
- * 
 */
 public interface KingdomFactory {

--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcArmy.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcArmy.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,12 +20,11 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

 /**
- * 
- * OrcArmy
- *
+ * OrcArmy.
 */
 public class OrcArmy implements Army {

--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcCastle.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcCastle.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,12 +20,11 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

 /**
- * 
- * OrcCastle
- *
+ * OrcCastle.
 */
 public class OrcCastle implements Castle {

--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKing.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKing.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,12 +20,11 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

 /**
- * 
- * OrcKing
- *
+ * OrcKing.
 */
 public class OrcKing implements King {

--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKingdomFactory.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKingdomFactory.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,23 +20,25 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

 /**
- * 
 * OrcKingdomFactory concrete factory.
- * 
 */
 public class OrcKingdomFactory implements KingdomFactory {

+  @Override
  public Castle createCastle() {
    return new OrcCastle();
  }

+  @Override
  public King createKing() {
    return new OrcKing();
  }

+  @Override
  public Army createArmy() {
    return new OrcArmy();
  }
--- a/abstract-factory/src/main/java/com/iluwatar/abstractfactory/module-info.java
+++ b/abstract-factory/src/main/java/com/iluwatar/abstractfactory/module-info.java
@ -0,0 +1,26 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+module com.iluwatar.abstractfactory {
+	requires org.slf4j;
+}
--- a/abstract-factory/src/test/java/com/iluwatar/abstractfactory/AbstractFactoryTest.java
+++ b/abstract-factory/src/test/java/com/iluwatar/abstractfactory/AbstractFactoryTest.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,52 +20,58 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;

-import org.junit.Before;
-import org.junit.Test;
+import com.iluwatar.abstractfactory.App.FactoryMaker;
+import com.iluwatar.abstractfactory.App.FactoryMaker.KingdomType;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;

+/**
+ * Test for abstract factory.
+ */
 public class AbstractFactoryTest {

  private App app = new App();
  private KingdomFactory elfFactory;
  private KingdomFactory orcFactory;

-  @Before
+  @BeforeEach
  public void setUp() {
-    elfFactory = new ElfKingdomFactory();
-    orcFactory = new OrcKingdomFactory();
+    elfFactory = FactoryMaker.makeFactory(KingdomType.ELF);
+    orcFactory = FactoryMaker.makeFactory(KingdomType.ORC);
  }

  @Test
  public void king() {
-    final King elfKing = app.getKing(elfFactory);
+    final var elfKing = app.getKing(elfFactory);
    assertTrue(elfKing instanceof ElfKing);
    assertEquals(ElfKing.DESCRIPTION, elfKing.getDescription());
-    final King orcKing = app.getKing(orcFactory);
+    final var orcKing = app.getKing(orcFactory);
    assertTrue(orcKing instanceof OrcKing);
    assertEquals(OrcKing.DESCRIPTION, orcKing.getDescription());
  }

  @Test
  public void castle() {
-    final Castle elfCastle = app.getCastle(elfFactory);
+    final var elfCastle = app.getCastle(elfFactory);
    assertTrue(elfCastle instanceof ElfCastle);
    assertEquals(ElfCastle.DESCRIPTION, elfCastle.getDescription());
-    final Castle orcCastle = app.getCastle(orcFactory);
+    final var orcCastle = app.getCastle(orcFactory);
    assertTrue(orcCastle instanceof OrcCastle);
    assertEquals(OrcCastle.DESCRIPTION, orcCastle.getDescription());
  }

  @Test
  public void army() {
-    final Army elfArmy = app.getArmy(elfFactory);
+    final var elfArmy = app.getArmy(elfFactory);
    assertTrue(elfArmy instanceof ElfArmy);
    assertEquals(ElfArmy.DESCRIPTION, elfArmy.getDescription());
-    final Army orcArmy = app.getArmy(orcFactory);
+    final var orcArmy = app.getArmy(orcFactory);
    assertTrue(orcArmy instanceof OrcArmy);
    assertEquals(OrcArmy.DESCRIPTION, orcArmy.getDescription());
  }
@ -73,9 +79,9 @@ public class AbstractFactoryTest {
  @Test
  public void createElfKingdom() {
    app.createKingdom(elfFactory);
-    final King king = app.getKing();
-    final Castle castle = app.getCastle();
-    final Army army = app.getArmy();
+    final var king = app.getKing();
+    final var castle = app.getCastle();
+    final var army = app.getArmy();
    assertTrue(king instanceof ElfKing);
    assertEquals(ElfKing.DESCRIPTION, king.getDescription());
    assertTrue(castle instanceof ElfCastle);
@ -87,9 +93,9 @@ public class AbstractFactoryTest {
  @Test
  public void createOrcKingdom() {
    app.createKingdom(orcFactory);
-    final King king = app.getKing();
-    final Castle castle = app.getCastle();
-    final Army army = app.getArmy();
+    final var king = app.getKing();
+    final var castle = app.getCastle();
+    final var army = app.getArmy();
    assertTrue(king instanceof OrcKing);
    assertEquals(OrcKing.DESCRIPTION, king.getDescription());
    assertTrue(castle instanceof OrcCastle);
--- a/abstract-factory/src/test/java/com/iluwatar/abstractfactory/AppTest.java
+++ b/abstract-factory/src/test/java/com/iluwatar/abstractfactory/AppTest.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,19 +20,17 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.abstractfactory;

-import org.junit.Test;
-
-import java.io.IOException;
+import org.junit.jupiter.api.Test;

 /**
 * Tests that Abstract Factory example runs without errors.
 */
 public class AppTest {
  @Test
-  public void test() throws IOException {
-    String[] args = {};
-    App.main(args);
+  public void test() {
+    App.main(new String[]{});
  }
 }
--- a/acyclic-visitor/README.md
+++ b/acyclic-visitor/README.md
@ -0,0 +1,42 @@
+---
+layout: pattern
+title: Acyclic Visitor
+folder: acyclic-visitor
+permalink: /patterns/acyclic-visitor/
+categories: Behavioral
+tags:
+ - Extensibility
+---
+
+## Intent
+Allow new functions to be added to existing class hierarchies without affecting those hierarchies, and without creating the troublesome dependency cycles that are inherent to the GOF VISITOR Pattern.
+
+## Class diagram
+![alt text](./etc/acyclic-visitor.png "Acyclic Visitor")
+
+## Applicability
+This pattern can be used:
+
+* When you need to add a new function to an existing hierarchy without the need to alter or affect that hierarchy.
+* When there are functions that operate upon a hierarchy, but which do not belong in the hierarchy itself. e.g. the ConfigureForDOS / ConfigureForUnix / ConfigureForX issue.
+* When you need to perform very different operations on an object depending upon its type.
+* When the visited class hierarchy will be frequently extended with new derivatives of the Element class.
+* When the recompilation, relinking, retesting or redistribution of the derivatives of Element is very expensive.
+
+## Consequences
+The good:
+
+* No dependency cycles between class hierarchies.
+* No need to recompile all the visitors if a new one is added.
+* Does not cause compilation failure in existing visitors if class hierarchy has a new member.
+
+The bad:
+
+* Violates the principle of least surprise or Liskov's Substitution principle by showing that it can accept all visitors but actually only being interested in particular visitors.
+* Parallel hierarchy of visitors has to be created for all members in visitable class hierarchy.
+
+## Related patterns
+* [Visitor Pattern](../visitor/)
+
+## Credits
+* [Acyclic Visitor](http://condor.depaul.edu/dmumaugh/OOT/Design-Principles/acv.pdf)
--- a/factory-method/etc/factory-method.ucls
+++ b/factory-method/etc/factory-method.ucls
@ -1,113 +1,111 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<class-diagram version="1.1.8" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true" 
-  realizations="true" associations="true" dependencies="false" nesting-relationships="true">  
-  <class id="1" language="java" name="com.iluwatar.factory.method.OrcBlacksmith" project="factory-method" 
-    file="/factory-method/src/main/java/com/iluwatar/factory/method/OrcBlacksmith.java" binary="false" 
+<class-diagram version="1.2.2" icons="true" always-add-relationships="false" generalizations="true" realizations="true" 
+  associations="true" dependencies="false" nesting-relationships="true" router="FAN">  
+  <interface id="1" language="java" name="com.iluwatar.acyclicvisitor.ModemVisitor" project="acyclic-visitor" 
+    file="/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ModemVisitor.java" binary="false" 
    corner="BOTTOM_RIGHT">    
-    <position height="106" width="280" x="-46" y="239"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <interface id="2" language="java" name="com.iluwatar.factory.method.Blacksmith" project="factory-method" 
-    file="/factory-method/src/main/java/com/iluwatar/factory/method/Blacksmith.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="88" width="280" x="114" y="385"/>    
+    <position height="-1" width="-1" x="860" y="67"/>    
    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
      sort-features="false" accessors="true" visibility="true">      
      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
      <operations public="true" package="true" protected="true" private="true" static="true"/>    
    </display>  
  </interface>  
-  <enumeration id="3" language="java" name="com.iluwatar.factory.method.WeaponType" project="factory-method" 
-    file="/factory-method/src/main/java/com/iluwatar/factory/method/WeaponType.java" binary="false" 
+  <class id="2" language="java" name="com.iluwatar.acyclicvisitor.Modem" project="acyclic-visitor" 
+    file="/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Modem.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="327" y="77"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <class id="3" language="java" name="com.iluwatar.acyclicvisitor.ConfigureForUnixVisitor" project="acyclic-visitor" 
+    file="/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitor.java" binary="false" 
    corner="BOTTOM_RIGHT">    
-    <position height="196" width="210" x="793" y="385"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </enumeration>  
-  <class id="4" language="java" name="com.iluwatar.factory.method.OrcWeapon" project="factory-method" 
-    file="/factory-method/src/main/java/com/iluwatar/factory/method/OrcWeapon.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="106" width="178" x="806" y="239"/>    
+    <position height="124" width="196" x="647" y="225"/>    
    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
      sort-features="false" accessors="true" visibility="true">      
      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
      <operations public="true" package="true" protected="true" private="true" static="true"/>    
    </display>  
  </class>  
-  <class id="5" language="java" name="com.iluwatar.factory.method.ElfWeapon" project="factory-method" 
-    file="/factory-method/src/main/java/com/iluwatar/factory/method/ElfWeapon.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="106" width="172" x="594" y="239"/>    
+  <class id="4" language="java" name="com.iluwatar.acyclicvisitor.Zoom" project="acyclic-visitor" 
+    file="/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Zoom.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="203" y="305"/>    
    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
      sort-features="false" accessors="true" visibility="true">      
      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
      <operations public="true" package="true" protected="true" private="true" static="true"/>    
    </display>  
  </class>  
-  <interface id="6" language="java" name="com.iluwatar.factory.method.Weapon" project="factory-method" 
-    file="/factory-method/src/main/java/com/iluwatar/factory/method/Weapon.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="70" width="159" x="594" y="385"/>    
+  <interface id="5" language="java" name="com.iluwatar.acyclicvisitor.HayesVisitor" project="acyclic-visitor" 
+    file="/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/HayesVisitor.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="1019" y="468"/>    
    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
      sort-features="false" accessors="true" visibility="true">      
      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
      <operations public="true" package="true" protected="true" private="true" static="true"/>    
    </display>  
  </interface>  
-  <class id="7" language="java" name="com.iluwatar.factory.method.ElfBlacksmith" project="factory-method" 
-    file="/factory-method/src/main/java/com/iluwatar/factory/method/ElfBlacksmith.java" binary="false" 
+  <interface id="6" language="java" name="com.iluwatar.acyclicvisitor.ZoomVisitor" project="acyclic-visitor" 
+    file="/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ZoomVisitor.java" binary="false" 
    corner="BOTTOM_RIGHT">    
-    <position height="106" width="280" x="274" y="239"/>    
+    <position height="-1" width="-1" x="758" y="467"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <class id="7" language="java" name="com.iluwatar.acyclicvisitor.Hayes" project="acyclic-visitor" 
+    file="/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Hayes.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="479" y="307"/>    
    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
      sort-features="false" accessors="true" visibility="true">      
      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
      <operations public="true" package="true" protected="true" private="true" static="true"/>    
    </display>  
  </class>  
-  <realization id="8">    
-    <end type="SOURCE" refId="4"/>    
-    <end type="TARGET" refId="6"/>  
-  </realization>  
-  <realization id="9">    
+  <class id="8" language="java" name="com.iluwatar.acyclicvisitor.ConfigureForDosVisitor" project="acyclic-visitor" 
+    file="/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitor.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="142" width="192" x="883" y="225"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <generalization id="9">    
    <end type="SOURCE" refId="7"/>    
    <end type="TARGET" refId="2"/>  
-  </realization>  
+  </generalization>  
  <realization id="10">    
-    <end type="SOURCE" refId="5"/>    
+    <end type="SOURCE" refId="8"/>    
    <end type="TARGET" refId="6"/>  
  </realization>  
-  <association id="11">    
-    <end type="SOURCE" refId="4" navigable="false">      
-      <attribute id="12" name="weaponType">        
-        <position height="0" width="0" x="0" y="0"/>      
-      </attribute>      
-      <multiplicity id="13" minimum="0" maximum="1">        
-        <position height="0" width="0" x="0" y="0"/>      
-      </multiplicity>    
-    </end>    
-    <end type="TARGET" refId="3" navigable="true"/>    
-    <display labels="true" multiplicity="true"/>  
-  </association>  
-  <realization id="14">    
-    <end type="SOURCE" refId="1"/>    
-    <end type="TARGET" refId="2"/>  
+  <realization id="11">    
+    <end type="SOURCE" refId="8"/>    
+    <end type="TARGET" refId="5"/>  
  </realization>  
-  <association id="15">    
-    <end type="SOURCE" refId="5" navigable="false">      
-      <attribute id="16" name="weaponType">        
-        <position height="0" width="0" x="0" y="0"/>      
-      </attribute>      
-      <multiplicity id="17" minimum="0" maximum="1">        
-        <position height="0" width="0" x="0" y="0"/>      
-      </multiplicity>    
-    </end>    
-    <end type="TARGET" refId="3" navigable="true"/>    
-    <display labels="true" multiplicity="true"/>  
-  </association>  
+  <realization id="12">    
+    <end type="SOURCE" refId="3"/>    
+    <end type="TARGET" refId="6"/>  
+  </realization>  
+  <realization id="13">    
+    <end type="SOURCE" refId="3"/>    
+    <end type="TARGET" refId="1"/>  
+  </realization>  
+  <realization id="14">    
+    <end type="SOURCE" refId="8"/>    
+    <end type="TARGET" refId="1"/>  
+  </realization>  
+  <generalization id="15">    
+    <end type="SOURCE" refId="4"/>    
+    <end type="TARGET" refId="2"/>  
+  </generalization>  
  <classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
    sort-features="false" accessors="true" visibility="true">    
    <attributes public="true" package="true" protected="true" private="true" static="true"/>    
--- a/acyclic-visitor/etc/acyclic-visitor.png
+++ b/acyclic-visitor/etc/acyclic-visitor.png
--- a/acyclic-visitor/etc/acyclic-visitor.urm.puml
+++ b/acyclic-visitor/etc/acyclic-visitor.urm.puml
@ -0,0 +1,53 @@
+@startuml
+package com.iluwatar.acyclicvisitor {
+  interface AllModemVisitor {
+  }
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  class ConfigureForDosVisitor {
+    - LOGGER : Logger {static}
+    + ConfigureForDosVisitor()
+    + visit(hayes : Hayes)
+    + visit(zoom : Zoom)
+  }
+  class ConfigureForUnixVisitor {
+    - LOGGER : Logger {static}
+    + ConfigureForUnixVisitor()
+    + visit(zoom : Zoom)
+  }
+  class Hayes {
+    - LOGGER : Logger {static}
+    + Hayes()
+    + accept(modemVisitor : ModemVisitor)
+    + toString() : String
+  }
+  interface HayesVisitor {
+    + visit(Hayes) {abstract}
+  }
+  abstract class Modem {
+    + Modem()
+    + accept(ModemVisitor) {abstract}
+  }
+  interface ModemVisitor {
+  }
+  class Zoom {
+    - LOGGER : Logger {static}
+    + Zoom()
+    + accept(modemVisitor : ModemVisitor)
+    + toString() : String
+  }
+  interface ZoomVisitor {
+    + visit(Zoom) {abstract}
+  }
+}
+AllModemVisitor --|> ZoomVisitor 
+AllModemVisitor --|> HayesVisitor 
+ConfigureForDosVisitor ..|> AllModemVisitor 
+ConfigureForUnixVisitor ..|> ZoomVisitor 
+Hayes --|> Modem 
+HayesVisitor --|> ModemVisitor 
+Zoom --|> Modem 
+ZoomVisitor --|> ModemVisitor 
+@enduml
--- a/acyclic-visitor/pom.xml
+++ b/acyclic-visitor/pom.xml
@ -0,0 +1,83 @@
+<!-- The MIT License Copyright © 2014-2019 Ilkka Seppälä Permission is hereby 
+	granted, free of charge, to any person obtaining a copy of this software 
+	and associated documentation files (the "Software"), to deal in the Software 
+	without restriction, including without limitation the rights to use, copy, 
+	modify, merge, publish, distribute, sublicense, and/or sell copies of the 
+	Software, and to permit persons to whom the Software is furnished to do so, 
+	subject to the following conditions: The above copyright notice and this 
+	permission notice shall be included in all copies or substantial portions 
+	of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY 
+	KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
+	MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN 
+	NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
+	DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
+	ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
+	DEALINGS IN THE SOFTWARE. -->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+
+	<parent>
+		<groupId>com.iluwatar</groupId>
+		<artifactId>java-design-patterns</artifactId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+
+	<artifactId>acyclic-visitor</artifactId>
+
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<maven.compiler.source>1.8</maven.compiler.source>
+		<maven.compiler.target>1.8</maven.compiler.target>
+	</properties>
+
+	<dependencies>
+		<!-- https://mvnrepository.com/artifact/org.assertj/assertj-core -->
+		<dependency>
+			<groupId>org.assertj</groupId>
+			<artifactId>assertj-core</artifactId>
+			<version>3.9.1</version>
+			<scope>test</scope>
+		</dependency>
+		<!-- https://mvnrepository.com/artifact/uk.org.lidalia/slf4j-test -->
+		<dependency>
+			<groupId>uk.org.lidalia</groupId>
+			<artifactId>slf4j-test</artifactId>
+			<version>1.2.0</version>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-all</artifactId>
+			<version>1.10.19</version>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+    <plugins>
+      <!-- Maven assembly plugin is invoked with default setting which we have 
+        in parent pom and specifying the class having main method -->
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-assembly-plugin</artifactId>
+        <executions>
+          <execution>
+            <configuration>
+              <archive>
+                <manifest>
+                  <mainClass>com.iluwatar.acyclicvisitor.App</mainClass>
+                </manifest>
+              </archive>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>
--- a/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/AllModemVisitor.java
+++ b/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/AllModemVisitor.java
@ -0,0 +1,32 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+/**
+ * All ModemVisitor interface extends all visitor interfaces. This interface provides ease of use
+ * when a visitor needs to visit all modem types.
+ */
+public interface AllModemVisitor extends ZoomVisitor, HayesVisitor {
+
+}
--- a/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/App.java
+++ b/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/App.java
@ -0,0 +1,54 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+/**
+ * The Acyclic Visitor pattern allows new functions to be added to existing class hierarchies
+ * without affecting those hierarchies, and without creating the dependency cycles that are inherent
+ * to the GoF Visitor pattern, by making the Visitor base class degenerate
+ *
+ * <p>In this example the visitor base class is {@link ModemVisitor}. The base class of the visited
+ * hierarchy is {@link Modem} and has two children {@link Hayes} and {@link Zoom} each one having
+ * its own visitor interface {@link HayesVisitor} and {@link ZoomVisitor} respectively. {@link
+ * ConfigureForUnixVisitor} and {@link ConfigureForDosVisitor} implement each derivative's visit
+ * method only if it is required
+ */
+public class App {
+
+  /**
+   * Program's entry point.
+   */
+  public static void main(String[] args) {
+    var conUnix = new ConfigureForUnixVisitor();
+    var conDos = new ConfigureForDosVisitor();
+
+    var zoom = new Zoom();
+    var hayes = new Hayes();
+
+    hayes.accept(conDos); // Hayes modem with Dos configurator
+    zoom.accept(conDos); // Zoom modem with Dos configurator
+    hayes.accept(conUnix); // Hayes modem with Unix configurator
+    zoom.accept(conUnix); // Zoom modem with Unix configurator   
+  }
+}
--- a/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitor.java
+++ b/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitor.java
@ -0,0 +1,46 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * ConfigureForDosVisitor class implements both zoom's and  hayes' visit method for Dos
+ * manufacturer.
+ */
+public class ConfigureForDosVisitor implements AllModemVisitor {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(ConfigureForDosVisitor.class);
+
+  @Override
+  public void visit(Hayes hayes) {
+    LOGGER.info(hayes + " used with Dos configurator.");
+  }
+
+  @Override
+  public void visit(Zoom zoom) {
+    LOGGER.info(zoom + " used with Dos configurator.");
+  }
+}
--- a/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitor.java
+++ b/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitor.java
@ -0,0 +1,41 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * ConfigureForUnixVisitor class implements zoom's visit method for Unix manufacturer, unlike
+ * traditional visitor pattern, this class may selectively implement visit for other modems.
+ */
+public class ConfigureForUnixVisitor implements ZoomVisitor {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(ConfigureForUnixVisitor.class);
+
+  @Override
+  public void visit(Zoom zoom) {
+    LOGGER.info(zoom + " used with Unix configurator.");
+  }
+}
--- a/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Hayes.java
+++ b/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Hayes.java
@ -0,0 +1,56 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Hayes class implements its accept method.
+ */
+public class Hayes extends Modem {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(ConfigureForDosVisitor.class);
+
+  /**
+   * Accepts all visitors but honors only HayesVisitor.
+   */
+  @Override
+  public void accept(ModemVisitor modemVisitor) {
+    if (modemVisitor instanceof HayesVisitor) {
+      ((HayesVisitor) modemVisitor).visit(this);
+    } else {
+      LOGGER.info("Only HayesVisitor is allowed to visit Hayes modem");
+    }
+
+  }
+
+  /**
+   * Hayes' modem's toString method.
+   */
+  @Override
+  public String toString() {
+    return "Hayes modem";
+  }
+}
--- a/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/HayesVisitor.java
+++ b/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/HayesVisitor.java
@ -0,0 +1,31 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+/**
+ * HayesVisitor interface.
+ */
+public interface HayesVisitor extends ModemVisitor {
+  void visit(Hayes hayes);
+}
--- a/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Modem.java
+++ b/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Modem.java
@ -0,0 +1,31 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+/**
+ * Modem abstract class.
+ */
+public abstract class Modem {
+  public abstract void accept(ModemVisitor modemVisitor);
+}
--- a/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ModemVisitor.java
+++ b/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ModemVisitor.java
@ -0,0 +1,32 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+/**
+ * ModemVisitor interface does not contain any visit methods so that it does not depend on the
+ * visited hierarchy. Each derivative's visit method is declared in its own visitor interface
+ */
+public interface ModemVisitor {
+  // Visitor is a degenerate base class for all visitors.
+}
--- a/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Zoom.java
+++ b/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Zoom.java
@ -0,0 +1,55 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Zoom class implements its accept method.
+ */
+public class Zoom extends Modem {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(ConfigureForDosVisitor.class);
+
+  /**
+   * Accepts all visitors but honors only ZoomVisitor.
+   */
+  @Override
+  public void accept(ModemVisitor modemVisitor) {
+    if (modemVisitor instanceof ZoomVisitor) {
+      ((ZoomVisitor) modemVisitor).visit(this);
+    } else {
+      LOGGER.info("Only ZoomVisitor is allowed to visit Zoom modem");
+    }
+  }
+
+  /**
+   * Zoom modem's toString method.
+   */
+  @Override
+  public String toString() {
+    return "Zoom modem";
+  }
+}
--- a/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ZoomVisitor.java
+++ b/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ZoomVisitor.java
@ -0,0 +1,31 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+/**
+ * ZoomVisitor interface.
+ */
+public interface ZoomVisitor extends ModemVisitor {
+  void visit(Zoom zoom);
+}
--- a/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/module-info.java
+++ b/acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/module-info.java
@ -0,0 +1,26 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+module com.iluwatar.acyclicvisitor {
+	requires org.slf4j;
+}
--- a/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/AppTest.java
+++ b/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/AppTest.java
@ -0,0 +1,37 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests that the Acyclic Visitor example runs without errors.
+ */
+public class AppTest {
+
+  @Test
+  public void test() {
+    App.main(new String[]{});
+  }
+}
--- a/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitorTest.java
+++ b/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitorTest.java
@ -0,0 +1,70 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.groups.Tuple.tuple;
+import static uk.org.lidalia.slf4jext.Level.INFO;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import uk.org.lidalia.slf4jtest.TestLogger;
+import uk.org.lidalia.slf4jtest.TestLoggerFactory;
+
+/**
+ * ConfigureForDosVisitor test class
+ */
+public class ConfigureForDosVisitorTest {
+
+  private TestLogger logger = TestLoggerFactory.getTestLogger(ConfigureForDosVisitor.class);
+  
+  @Test
+  public void testVisitForZoom() {    
+    var conDos = new ConfigureForDosVisitor();
+    var zoom = new Zoom();
+    
+    conDos.visit(zoom);
+    
+    assertThat(logger.getLoggingEvents())
+        .extracting("level", "message")
+        .contains(tuple(INFO, zoom + " used with Dos configurator."));
+  }
+  
+  @Test
+  public void testVisitForHayes() {
+    var conDos = new ConfigureForDosVisitor();
+    var hayes = new Hayes();
+    
+    conDos.visit(hayes);
+    
+    assertThat(logger.getLoggingEvents())
+        .extracting("level", "message")
+        .contains(tuple(INFO, hayes + " used with Dos configurator."));
+  }
+  
+  @AfterEach
+  public void clearLoggers() {
+    TestLoggerFactory.clear();
+  }
+}
--- a/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitorTest.java
+++ b/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitorTest.java
@ -0,0 +1,59 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.groups.Tuple.tuple;
+import static uk.org.lidalia.slf4jext.Level.INFO;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+
+import uk.org.lidalia.slf4jtest.TestLogger;
+import uk.org.lidalia.slf4jtest.TestLoggerFactory;
+
+/**
+ * ConfigureForUnixVisitor test class
+ */
+public class ConfigureForUnixVisitorTest {
+  
+  private static final TestLogger LOGGER = TestLoggerFactory.getTestLogger(ConfigureForUnixVisitor.class);
+  
+  @AfterEach
+  public void clearLoggers() {
+    TestLoggerFactory.clear();
+  }
+  
+  @Test
+  public void testVisitForZoom() {
+    var conUnix = new ConfigureForUnixVisitor();
+    var zoom = new Zoom();
+    
+    conUnix.visit(zoom);
+    
+    assertThat(LOGGER.getLoggingEvents())
+        .extracting("level", "message")
+        .contains(tuple(INFO, zoom + " used with Unix configurator."));
+  }
+}
--- a/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/HayesTest.java
+++ b/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/HayesTest.java
@ -0,0 +1,56 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyZeroInteractions;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Hayes test class
+ */
+public class HayesTest {
+
+  @Test
+  public void testAcceptForDos() {  
+    var hayes = new Hayes();
+    var mockVisitor = mock(ConfigureForDosVisitor.class);
+    
+    hayes.accept(mockVisitor);
+    verify((HayesVisitor)mockVisitor).visit(eq(hayes));
+  }
+  
+  @Test
+  public void testAcceptForUnix() {    
+    var hayes = new Hayes();
+    var mockVisitor = mock(ConfigureForUnixVisitor.class);
+    
+    hayes.accept(mockVisitor);
+    
+    verifyZeroInteractions(mockVisitor);
+  }
+}
--- a/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ZoomTest.java
+++ b/acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ZoomTest.java
@ -0,0 +1,55 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.acyclicvisitor;
+
+
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.mock;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * Zoom test class
+ */
+public class ZoomTest {
+  
+  @Test
+  public void testAcceptForDos() {  
+    var zoom = new Zoom();
+    var mockVisitor = mock(ConfigureForDosVisitor.class);
+    
+    zoom.accept(mockVisitor);
+    verify((ZoomVisitor)mockVisitor).visit(eq(zoom));
+  }
+  
+  @Test
+  public void testAcceptForUnix() {
+    var zoom = new Zoom();
+    var mockVisitor = mock(ConfigureForUnixVisitor.class);
+    
+    zoom.accept(mockVisitor);
+    verify((ZoomVisitor)mockVisitor).visit(eq(zoom));
+  }
+}
--- a/adapter/README.md
+++ b/adapter/README.md
@ -3,12 +3,9 @@ layout: pattern
 title: Adapter
 folder: adapter
 permalink: /patterns/adapter/
-pumlid: DSR14S8m30J0Lg20M7-wEMnDOiPMFDA9j0yyUEtUkzMHJTF7xI1NF4GSLzaxZtncgDVJgCPIpobzv0N2vOKtjgRHTziMI7KBcOXl10thfxB-Nz9dMJd71m00
 categories: Structural
 tags:
- - Java
- - Gang Of Four
- - Difficulty-Beginner
+ - Gang of Four
 ---

 ## Also known as
@ -19,7 +16,87 @@ Convert the interface of a class into another interface the clients
 expect. Adapter lets classes work together that couldn't otherwise because of
 incompatible interfaces.

-![alt text](./etc/adapter.png "Adapter")
+## Explanation
+
+Real world example
+
+> Consider that you have some pictures in your memory card and you need to transfer them to your computer. In order to transfer them you need some kind of adapter that is compatible with your computer ports so that you can attach memory card to your computer. In this case card reader is an adapter.
+> Another example would be the famous power adapter; a three legged plug can't be connected to a two pronged outlet, it needs to use a power adapter that makes it compatible with the two pronged outlet.
+> Yet another example would be a translator translating words spoken by one person to another
+
+In plain words
+
+> Adapter pattern lets you wrap an otherwise incompatible object in an adapter to make it compatible with another class.
+
+Wikipedia says
+
+> In software engineering, the adapter pattern is a software design pattern that allows the interface of an existing class to be used as another interface. It is often used to make existing classes work with others without modifying their source code.
+
+**Programmatic Example**
+
+Consider a captain that can only use rowing boats and cannot sail at all.
+
+First we have interfaces `RowingBoat` and `FishingBoat`
+
+```java
+public interface RowingBoat {
+  void row();
+}
+
+public class FishingBoat {
+  private static final Logger LOGGER = LoggerFactory.getLogger(FishingBoat.class);
+  public void sail() {
+    LOGGER.info("The fishing boat is sailing");
+  }
+}
+```
+
+And captain expects an implementation of `RowingBoat` interface to be able to move
+
+```java
+public class Captain {
+
+  private RowingBoat rowingBoat;
+  // default constructor and setter for rowingBoat
+  public Captain(RowingBoat rowingBoat) {
+    this.rowingBoat = rowingBoat;
+  }
+
+  public void row() {
+    rowingBoat.row();
+  }
+}
+```
+
+Now let's say the pirates are coming and our captain needs to escape but there is only fishing boat available. We need to create an adapter that allows the captain to operate the fishing boat with his rowing boat skills.
+
+```java
+public class FishingBoatAdapter implements RowingBoat {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(FishingBoatAdapter.class);
+
+  private FishingBoat boat;
+
+  public FishingBoatAdapter() {
+    boat = new FishingBoat();
+  }
+
+  @Override
+  public void row() {
+    boat.sail();
+  }
+}
+```
+
+And now the `Captain` can use the `FishingBoat` to escape the pirates.
+
+```java
+var captain = new Captain(new FishingBoatAdapter());
+captain.row();
+```
+
+## Class diagram
+![alt text](./etc/adapter.urm.png "Adapter class diagram")

 ## Applicability
 Use the Adapter pattern when
@ -27,6 +104,20 @@ Use the Adapter pattern when
 * you want to use an existing class, and its interface does not match the one you need
 * you want to create a reusable class that cooperates with unrelated or unforeseen classes, that is, classes that don't necessarily have compatible interfaces
 * you need to use several existing subclasses, but it's impractical to adapt their interface by subclassing every one. An object adapter can adapt the interface of its parent class.
+* most of the applications using third party libraries use adapters as a middle layer between the application and the 3rd party library to decouple the application from the library. If another library has to be used only an adapter for the new library is required without having to change the application code.
+
+## Consequences:
+Class and object adapters have different trade-offs. A class adapter
+
+*	adapts Adaptee to Target by committing to a concrete Adaptee class. As a consequence, a class adapter won’t work when we want to adapt a class and all its subclasses.
+*	let’s Adapter override some of Adaptee’s behavior, since Adapter is a subclass of Adaptee.
+*	introduces only one object, and no additional pointer indirection is needed to get to the adaptee.
+
+An object adapter	
+
+*	let’s a single Adapter work with many Adaptees—that is, the Adaptee itself and all of its subclasses (if any). The Adapter can also add functionality to all Adaptees at once.
+*	makes it harder to override Adaptee behavior. It will require subclassing Adaptee and making Adapter refer to the subclass rather than the Adaptee itself.
+

 ## Real world examples

@ -38,5 +129,7 @@ Use the Adapter pattern when

 ## Credits

-* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)
-* [J2EE Design Patterns](http://www.amazon.com/J2EE-Design-Patterns-William-Crawford/dp/0596004273/ref=sr_1_2)
+* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59)
+* [J2EE Design Patterns](https://www.amazon.com/gp/product/0596004273/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596004273&linkCode=as2&tag=javadesignpat-20&linkId=48d37c67fb3d845b802fa9b619ad8f31)
+* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b)
+* [Refactoring to Patterns](https://www.amazon.com/gp/product/0321213351/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0321213351&linkCode=as2&tag=javadesignpat-20&linkId=2a76fcb387234bc71b1c61150b3cc3a7)
--- a/adapter/etc/adapter.png
+++ b/adapter/etc/adapter.png
--- a/adapter/etc/adapter.urm.png
+++ b/adapter/etc/adapter.urm.png
--- a/adapter/etc/adapter.urm.puml
+++ b/adapter/etc/adapter.urm.puml
@ -1,35 +1,31 @@
@startuml
 package com.iluwatar.adapter {
-  interface BattleShip {
-    + fire() {abstract}
-    + move() {abstract}
-  }
-  class BattleFishingBoat {
-    - boat : FishingBoat
-    + BattleFishingBoat()
-    + fire()
-    + move()
-  }
  class App {
-    + App()
+    - App()
    + main(args : String[]) {static}
  }
  class Captain {
-    - battleship : BattleShip
+    - rowingBoat : RowingBoat
    + Captain()
-    + Captain(battleship : BattleShip)
-    + fire()
-    + move()
-    + setBattleship(battleship : BattleShip)
+    + Captain(boat : RowingBoat)
+    ~ row()
+    ~ setRowingBoat(boat : RowingBoat)
  }
-  class FishingBoat {
-    + FishingBoat()
-    + fish()
-    + sail()
+  ~class FishingBoat {
+    - LOGGER : Logger {static}
+    ~ FishingBoat()
+    ~ sail()
+  }
+  class FishingBoatAdapter {
+    - boat : FishingBoat
+    + FishingBoatAdapter()
+    + row()
+  }
+  interface RowingBoat {
+    + row() {abstract}
  }
 }
-BattleFishingBoat -->  "-boat" FishingBoat
-Captain -->  "-battleship" BattleShip
-BattleFishingBoat ..|> BattleShip 
-Captain ..|> BattleShip 
+FishingBoatAdapter -->  "-boat" FishingBoat
+Captain -->  "-rowingBoat" RowingBoat
+FishingBoatAdapter ..|> RowingBoat 
@enduml
--- a/adapter/pom.xml
+++ b/adapter/pom.xml
@ -1,47 +1,61 @@
 <?xml version="1.0"?>
-<!--
-
-    The MIT License
-    Copyright (c) 2014 Ilkka Seppälä
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-
-->
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-  <modelVersion>4.0.0</modelVersion>
-  <parent>
-    <groupId>com.iluwatar</groupId>
-    <artifactId>java-design-patterns</artifactId>
-    <version>1.13.0</version>
-  </parent>
-  <artifactId>adapter</artifactId>
-  <dependencies>
-    <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
-      <scope>test</scope>
-    </dependency>
-  </dependencies>
+<!-- The MIT License Copyright © 2014-2019 Ilkka Seppälä Permission is hereby 
+	granted, free of charge, to any person obtaining a copy of this software 
+	and associated documentation files (the "Software"), to deal in the Software 
+	without restriction, including without limitation the rights to use, copy, 
+	modify, merge, publish, distribute, sublicense, and/or sell copies of the 
+	Software, and to permit persons to whom the Software is furnished to do so, 
+	subject to the following conditions: The above copyright notice and this 
+	permission notice shall be included in all copies or substantial portions 
+	of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY 
+	KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
+	MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN 
+	NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
+	DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
+	ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
+	DEALINGS IN THE SOFTWARE. -->
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>com.iluwatar</groupId>
+		<artifactId>java-design-patterns</artifactId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>adapter</artifactId>
+	<dependencies>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-core</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<!-- Maven assembly plugin is invoked with default setting which we have 
+				in parent pom and specifying the class having main method -->
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.adapter.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
 </project>
--- a/adapter/src/main/java/com/iluwatar/adapter/App.java
+++ b/adapter/src/main/java/com/iluwatar/adapter/App.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,6 +20,7 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.adapter;

 /**
@ -28,33 +29,33 @@ package com.iluwatar.adapter;
 * The Adapter design pattern allows otherwise incompatible classes to work together by converting
 * the interface of one class into an interface expected by the clients.
 *
- * <p>
- * There are two variations of the Adapter pattern: The class adapter implements the adaptee's
+ * <p>There are two variations of the Adapter pattern: The class adapter implements the adaptee's
 * interface whereas the object adapter uses composition to contain the adaptee in the adapter
 * object. This example uses the object adapter approach.
 *
- * <p>
- * The Adapter ({@link BattleFishingBoat}) converts the interface of the adaptee class (
- * {@link FishingBoat}) into a suitable one expected by the client ( {@link BattleShip} ).
- *
- * <p>
- * The story of this implementation is this. <br>
- * Pirates are coming! we need a {@link BattleShip} to fight! We have a {@link FishingBoat} and our
- * captain. We have no time to make up a new ship! we need to reuse this {@link FishingBoat}. The
- * captain needs a battleship which can fire and move. The spec is in {@link BattleShip}. We will
- * use the Adapter pattern to reuse {@link FishingBoat}.
+ * <p>The Adapter ({@link FishingBoatAdapter}) converts the interface of the adaptee class ({@link
+ * FishingBoat}) into a suitable one expected by the client ({@link RowingBoat}).
 *
+ * <p>The story of this implementation is this. <br> Pirates are coming! we need a {@link
+ * RowingBoat} to flee! We have a {@link FishingBoat} and our captain. We have no time to make up a
+ * new ship! we need to reuse this {@link FishingBoat}. The captain needs a rowing boat which he can
+ * operate. The spec is in {@link RowingBoat}. We will use the Adapter pattern to reuse {@link
+ * FishingBoat}.
 */
-public class App {
+public final class App {
+
+  private App() {
+  }

  /**
   * Program entry point.
   *
   * @param args command line args
   */
-  public static void main(String[] args) {
-    Captain captain = new Captain(new BattleFishingBoat());
-    captain.move();
-    captain.fire();
+  public static void main(final String[] args) {
+    // The captain can only operate rowing boats but with adapter he is able to
+    // use fishing boats as well
+    var captain = new Captain(new FishingBoatAdapter());
+    captain.row();
  }
 }
--- a/adapter/src/main/java/com/iluwatar/adapter/Captain.java
+++ b/adapter/src/main/java/com/iluwatar/adapter/Captain.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,36 +20,29 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.adapter;

 /**
- * The Captain uses {@link BattleShip} to fight. <br>
- * This is the client in the pattern.
+ * The Captain uses {@link RowingBoat} to sail. <br> This is the client in the pattern.
 */
-public class Captain implements BattleShip {
+public final class Captain {

-  private BattleShip battleship;
+  private RowingBoat rowingBoat;

  public Captain() {
-
  }

-  public Captain(BattleShip battleship) {
-    this.battleship = battleship;
+  public Captain(final RowingBoat boat) {
+    this.rowingBoat = boat;
  }

-  public void setBattleship(BattleShip battleship) {
-    this.battleship = battleship;
+  void setRowingBoat(final RowingBoat boat) {
+    this.rowingBoat = boat;
  }

-  @Override
-  public void fire() {
-    battleship.fire();
-  }
-
-  @Override
-  public void move() {
-    battleship.move();
+  void row() {
+    rowingBoat.row();
  }

 }
--- a/adapter/src/main/java/com/iluwatar/adapter/FishingBoat.java
+++ b/adapter/src/main/java/com/iluwatar/adapter/FishingBoat.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,21 +20,23 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.adapter;

+import static org.slf4j.LoggerFactory.getLogger;
+
+import org.slf4j.Logger;
+
 /**
- *
- * Device class (adaptee in the pattern). We want to reuse this class
- *
+ * Device class (adaptee in the pattern). We want to reuse this class. Fishing boat moves by
+ * sailing.
 */
-public class FishingBoat {
+final class FishingBoat {

-  public void sail() {
-    System.out.println("The Boat is moving to that place");
-  }
+  private static final Logger LOGGER = getLogger(FishingBoat.class);

-  public void fish() {
-    System.out.println("fishing ...");
+  void sail() {
+    LOGGER.info("The fishing boat is sailing");
  }

 }
--- a/adapter/src/main/java/com/iluwatar/adapter/FishingBoatAdapter.java
+++ b/adapter/src/main/java/com/iluwatar/adapter/FishingBoatAdapter.java
@ -0,0 +1,41 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.adapter;
+
+/**
+ * Adapter class. Adapts the interface of the device ({@link FishingBoat}) into {@link RowingBoat}
+ * interface expected by the client ({@link Captain}).
+ */
+public class FishingBoatAdapter implements RowingBoat {
+
+  private FishingBoat boat;
+
+  public FishingBoatAdapter() {
+    boat = new FishingBoat();
+  }
+
+  public final void row() {
+    boat.sail();
+  }
+}
--- a/adapter/src/main/java/com/iluwatar/adapter/RowingBoat.java
+++ b/adapter/src/main/java/com/iluwatar/adapter/RowingBoat.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,17 +20,14 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.adapter;

 /**
- * The interface expected by the client.<br>
- * A Battleship can fire and move.
- *
+ * The interface expected by the client.<br> A rowing boat is rowed to move.
 */
-public interface BattleShip {
+public interface RowingBoat {

-  void fire();
-
-  void move();
+  void row();

 }
--- a/adapter/src/main/java/com/iluwatar/adapter/package-info.java
+++ b/adapter/src/main/java/com/iluwatar/adapter/package-info.java
@ -0,0 +1,24 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.iluwatar.adapter;
--- a/adapter/src/test/java/com/iluwatar/adapter/AdapterPatternTest.java
+++ b/adapter/src/test/java/com/iluwatar/adapter/AdapterPatternTest.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,64 +20,58 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.adapter;

-import org.junit.Before;
-import org.junit.Test;
-
-import java.util.HashMap;
-import java.util.Map;
-
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.verify;

+import java.util.HashMap;
+import java.util.Map;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
 /**
 * Test class
- * 
 */
 public class AdapterPatternTest {

  private Map<String, Object> beans;

-  private static final String BATTLESHIP_BEAN = "engineer";
+  private static final String FISHING_BEAN = "fisher";

-  private static final String CAPTAIN_BEAN = "captain";
+  private static final String ROWING_BEAN = "captain";

  /**
   * This method runs before the test execution and sets the bean objects in the beans Map.
   */
-  @Before
+  @BeforeEach
  public void setup() {
    beans = new HashMap<>();

-    BattleFishingBoat battleFishingBoat = spy(new BattleFishingBoat());
-    beans.put(BATTLESHIP_BEAN, battleFishingBoat);
+    var fishingBoatAdapter = spy(new FishingBoatAdapter());
+    beans.put(FISHING_BEAN, fishingBoatAdapter);

-    Captain captain = new Captain();
-    captain.setBattleship((BattleFishingBoat) beans.get(BATTLESHIP_BEAN));
-    beans.put(CAPTAIN_BEAN, captain);
+    var captain = new Captain();
+    captain.setRowingBoat((FishingBoatAdapter) beans.get(FISHING_BEAN));
+    beans.put(ROWING_BEAN, captain);
  }

  /**
-   * This test asserts that when we use the move() method on a captain bean(client), it is
-   * internally calling move method on the battleship object. The Adapter ({@link BattleFishingBoat}
-   * ) converts the interface of the target class ( {@link FishingBoat}) into a suitable one
-   * expected by the client ({@link Captain} ).
+   * This test asserts that when we use the row() method on a captain bean(client), it is internally
+   * calling sail method on the fishing boat object. The Adapter ({@link FishingBoatAdapter} )
+   * converts the interface of the target class ( {@link FishingBoat}) into a suitable one expected
+   * by the client ({@link Captain} ).
   */
  @Test
  public void testAdapter() {
-    BattleShip captain = (BattleShip) beans.get(CAPTAIN_BEAN);
+    var captain = (Captain) beans.get(ROWING_BEAN);

    // when captain moves
-    captain.move();
+    captain.row();

    // the captain internally calls the battleship object to move
-    BattleShip battleship = (BattleShip) beans.get(BATTLESHIP_BEAN);
-    verify(battleship).move();
-
-    // same with above with firing
-    captain.fire();
-    verify(battleship).fire();
-
+    var adapter = (RowingBoat) beans.get(FISHING_BEAN);
+    verify(adapter).row();
  }
 }
--- a/adapter/src/test/java/com/iluwatar/adapter/AppTest.java
+++ b/adapter/src/test/java/com/iluwatar/adapter/AppTest.java
@ -1,6 +1,6 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
@ -20,19 +20,17 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.adapter;

-import org.junit.Test;
-
-import java.io.IOException;
+import org.junit.jupiter.api.Test;

 /**
 * Tests that Adapter example runs without errors.
 */
 public class AppTest {
  @Test
-  public void test() throws IOException {
-    String[] args = {};
-    App.main(args);
+  public void test() {
+    App.main(new String[]{});
  }
 }
--- a/aggregator-microservices/README.md
+++ b/aggregator-microservices/README.md
@ -3,11 +3,9 @@ layout: pattern
 title: Aggregator Microservices
 folder: aggregator-microservices
 permalink: /patterns/aggregator-microservices/
-pumlid: JOov3SCm301NIGQGs7iRXYPa1g8ayB7NjuiKwGvtmBrbKC-Tq_hhY5Y-0HXUjKaS-Kbdepc2HrIQ2jBpma23BvvOTdPfeooCO1iEYlu0O6l63MDQKI6Rp-CKOWSE-ey_NzEqhjH-0m00
 categories: Architectural
 tags:
- Java
- Spring
+- Cloud distributed
 ---

 ## Intent
@ -19,6 +17,8 @@ More variations of the aggregator are:
 - Chained Microservice Design Pattern: In this case each microservice is dependent/ chained to a series 
 of other microservices.

+## Class diagram
+
 ![alt text](./etc/aggregator-microservice.png "Aggregator Microservice")

 ## Applicability
@ -27,4 +27,4 @@ Use the Aggregator Microservices pattern when you need a unified API for various

 ## Credits

-* [Microservice Design Patterns](http://blog.arungupta.me/microservice-design-patterns/)
+* [Microservice Design Patterns](http://web.archive.org/web/20190705163602/http://blog.arungupta.me/microservice-design-patterns/)
--- a/aggregator-microservices/aggregator-service/etc/aggregator-service.urm.puml
+++ b/aggregator-microservices/aggregator-service/etc/aggregator-service.urm.puml
@ -1,16 +1,15 @@
@startuml
 package com.iluwatar.aggregator.microservices {
-  class ProductInventoryClientImpl {
-    + ProductInventoryClientImpl()
-    + getProductInventories() : int
+  class Aggregator {
+    - informationClient : ProductInformationClient
+    - inventoryClient : ProductInventoryClient
+    + Aggregator()
+    + getProduct() : Product
  }
  class App {
    + App()
    + main(args : String[]) {static}
  }
-  interface ProductInventoryClient {
-    + getProductInventories() : int {abstract}
-  }
  class Product {
    - productInventories : int
    - title : String
@ -20,22 +19,25 @@ package com.iluwatar.aggregator.microservices {
    + setProductInventories(productInventories : int)
    + setTitle(title : String)
  }
-  class Aggregator {
-    - informationClient : ProductInformationClient
-    - inventoryClient : ProductInventoryClient
-    + Aggregator()
-    + getProduct() : Product
-  }
-  class ProductInformationClientImpl {
-    + ProductInformationClientImpl()
-    + getProductTitle() : String
-  }
  interface ProductInformationClient {
    + getProductTitle() : String {abstract}
  }
+  class ProductInformationClientImpl {
+    - LOGGER : Logger {static}
+    + ProductInformationClientImpl()
+    + getProductTitle() : String
+  }
+  interface ProductInventoryClient {
+    + getProductInventories() : Integer {abstract}
+  }
+  class ProductInventoryClientImpl {
+    - LOGGER : Logger {static}
+    + ProductInventoryClientImpl()
+    + getProductInventories() : Integer
+  }
 }
-Aggregator -->  "-inventoryClient" ProductInventoryClient
 Aggregator -->  "-informationClient" ProductInformationClient
-ProductInventoryClientImpl ..|> ProductInventoryClient 
+Aggregator -->  "-inventoryClient" ProductInventoryClient
 ProductInformationClientImpl ..|> ProductInformationClient 
+ProductInventoryClientImpl ..|> ProductInventoryClient 
@enduml
--- a/aggregator-microservices/aggregator-service/pom.xml
+++ b/aggregator-microservices/aggregator-service/pom.xml
@ -1,88 +1,81 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<!--
-
-    The MIT License
-    Copyright (c) 2014 Ilkka Seppälä
-
-    Permission is hereby granted, free of charge, to any person obtaining a copy
-    of this software and associated documentation files (the "Software"), to deal
-    in the Software without restriction, including without limitation the rights
-    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-    copies of the Software, and to permit persons to whom the Software is
-    furnished to do so, subject to the following conditions:
-
-    The above copyright notice and this permission notice shall be included in
-    all copies or substantial portions of the Software.
-
-    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-    THE SOFTWARE.
-
-->
+<!-- The MIT License Copyright © 2014-2019 Ilkka Seppälä Permission is hereby 
+	granted, free of charge, to any person obtaining a copy of this software 
+	and associated documentation files (the "Software"), to deal in the Software 
+	without restriction, including without limitation the rights to use, copy, 
+	modify, merge, publish, distribute, sublicense, and/or sell copies of the 
+	Software, and to permit persons to whom the Software is furnished to do so, 
+	subject to the following conditions: The above copyright notice and this 
+	permission notice shall be included in all copies or substantial portions 
+	of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY 
+	KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 
+	MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN 
+	NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
+	DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
+	ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
+	DEALINGS IN THE SOFTWARE. -->
 <project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <parent>
-        <artifactId>aggregator-microservices</artifactId>
-        <groupId>com.iluwatar</groupId>
-        <version>1.13.0</version>
-    </parent>
-    <modelVersion>4.0.0</modelVersion>
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<parent>
+		<artifactId>aggregator-microservices</artifactId>
+		<groupId>com.iluwatar</groupId>
+		<version>1.23.0-SNAPSHOT</version>
+	</parent>
+	<modelVersion>4.0.0</modelVersion>
+	<artifactId>aggregator-service</artifactId>
+	<packaging>jar</packaging>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework</groupId>
+			<artifactId>spring-webmvc</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.junit.jupiter</groupId>
+			<artifactId>junit-jupiter-engine</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-core</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>

-    <artifactId>aggregator-service</artifactId>
-    <packaging>jar</packaging>
-
-    <dependencyManagement>
-        <dependencies>
-            <dependency>
-                <groupId>org.springframework.boot</groupId>
-                <artifactId>spring-boot-dependencies</artifactId>
-            </dependency>
-        </dependencies>
-    </dependencyManagement>
-    <dependencies>
-        <dependency>
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-webmvc</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>org.springframework.boot</groupId>
-            <artifactId>spring-boot-starter-web</artifactId>
-        </dependency>
-        <dependency>
-            <groupId>junit</groupId>
-            <artifactId>junit</artifactId>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.mockito</groupId>
-            <artifactId>mockito-core</artifactId>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.apache.httpcomponents</groupId>
-            <artifactId>httpclient</artifactId>
-        </dependency>
-    </dependencies>
-
-    <build>
-        <plugins>
-            <plugin>
-                <groupId>org.springframework.boot</groupId>
-                <artifactId>spring-boot-maven-plugin</artifactId>
-                <version>${spring-boot.version}</version>
-                <executions>
-                    <execution>
-                        <goals>
-                            <goal>repackage</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-        </plugins>
-    </build>
-</project>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+				<executions>
+					<execution>
+						<goals>
+							<goal>repackage</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
+			<!-- Maven assembly plugin is invoked with default setting which we have 
+				in parent pom and specifying the class having main method -->
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-assembly-plugin</artifactId>
+				<executions>
+					<execution>
+						<configuration>
+							<archive>
+								<manifest>
+									<mainClass>com.iluwatar.aggregator.microservices.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+</project>
--- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java
+++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p/>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p/>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p/>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,16 +20,19 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.aggregator.microservices;

-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RestController;
+import static java.util.Objects.requireNonNullElse;

 import javax.annotation.Resource;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RestController;

 /**
- * The aggregator aggregates calls on various micro-services, collects
- * data and further publishes them under a REST endpoint.
+ * The aggregator aggregates calls on various micro-services, collects data and further publishes
+ * them under a REST endpoint.
 */
@RestController
 public class Aggregator {
@ -47,11 +50,19 @@ public class Aggregator {
   *
   * @return a Product.
   */
-  @RequestMapping("/product")
+  @RequestMapping(path = "/product", method = RequestMethod.GET)
  public Product getProduct() {
-    Product product = new Product();
-    product.setTitle(informationClient.getProductTitle());
-    product.setProductInventories(inventoryClient.getProductInventories());
+
+    var product = new Product();
+    var productTitle = informationClient.getProductTitle();
+    var productInventory = inventoryClient.getProductInventories();
+
+    //Fallback to error message
+    product.setTitle(requireNonNullElse(productTitle, "Error: Fetching Product Title Failed"));
+
+    //Fallback to default error inventory
+    product.setProductInventories(requireNonNullElse(productInventory, -1));
+
    return product;
  }

--- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/App.java
+++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/App.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p/>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p/>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p/>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,16 +20,20 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.aggregator.microservices;

 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;

+/**
+ * Spring Boot EntryPoint Class.
+ */
@SpringBootApplication
 public class App {

  /**
-   * Program entry point
+   * Program entry point.
   *
   * @param args command line args
   */
--- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Product.java
+++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Product.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p/>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p/>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p/>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,6 +20,7 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.aggregator.microservices;

 /**
--- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInformationClient.java
+++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInformationClient.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p/>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p/>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p/>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,6 +20,7 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.aggregator.microservices;

 /**
--- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInformationClientImpl.java
+++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInformationClientImpl.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p/>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p/>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p/>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,16 +20,17 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.aggregator.microservices;

-import org.apache.http.client.methods.CloseableHttpResponse;
-import org.apache.http.client.methods.HttpGet;
-import org.apache.http.impl.client.CloseableHttpClient;
-import org.apache.http.impl.client.HttpClients;
-import org.apache.http.util.EntityUtils;
-import org.springframework.stereotype.Component;
-
 import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;

 /**
 * An adapter to communicate with information micro-service.
@ -37,17 +38,23 @@ import java.io.IOException;
@Component
 public class ProductInformationClientImpl implements ProductInformationClient {

+  private static final Logger LOGGER = LoggerFactory.getLogger(ProductInformationClientImpl.class);
+
  @Override
  public String getProductTitle() {
-    String response = null;
-    try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
-      HttpGet httpGet = new HttpGet("http://localhost:51515/information");
-      try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) {
-        response = EntityUtils.toString(httpResponse.getEntity());
-      }
-    } catch (IOException e) {
-      e.printStackTrace();
+    var request = HttpRequest.newBuilder()
+        .GET()
+        .uri(URI.create("http://localhost:51515/information"))
+        .build();
+    var client = HttpClient.newHttpClient();
+    try {
+      var httpResponse = client.send(request, HttpResponse.BodyHandlers.ofString());
+      return httpResponse.body();
+    } catch (IOException ioe) {
+      LOGGER.error("IOException Occurred", ioe);
+    } catch (InterruptedException ie) {
+      LOGGER.error("InterruptedException Occurred", ie);
    }
-    return response;
+    return null;
  }
 }
--- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClient.java
+++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClient.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p/>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p/>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p/>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,6 +20,7 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.aggregator.microservices;

 /**
@ -27,5 +28,5 @@ package com.iluwatar.aggregator.microservices;
 */
 public interface ProductInventoryClient {

-  int getProductInventories();
+  Integer getProductInventories();
 }
--- a/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java
+++ b/aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p/>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p/>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p/>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,16 +20,17 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.aggregator.microservices;

-import org.apache.http.client.methods.CloseableHttpResponse;
-import org.apache.http.client.methods.HttpGet;
-import org.apache.http.impl.client.CloseableHttpClient;
-import org.apache.http.impl.client.HttpClients;
-import org.apache.http.util.EntityUtils;
-import org.springframework.stereotype.Component;
-
 import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;

 /**
 * An adapter to communicate with inventory micro-service.
@ -37,17 +38,29 @@ import java.io.IOException;
@Component
 public class ProductInventoryClientImpl implements ProductInventoryClient {

+  private static final Logger LOGGER = LoggerFactory.getLogger(ProductInventoryClientImpl.class);
+
  @Override
-  public int getProductInventories() {
-    String response = "0";
-    try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
-      HttpGet httpGet = new HttpGet("http://localhost:51516/inventories");
-      try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) {
-        response = EntityUtils.toString(httpResponse.getEntity());
-      }
-    } catch (IOException e) {
-      e.printStackTrace();
+  public Integer getProductInventories() {
+    var response = "";
+
+    var request = HttpRequest.newBuilder()
+        .GET()
+        .uri(URI.create("http://localhost:51516/inventories"))
+        .build();
+    var client = HttpClient.newHttpClient();
+    try {
+      var httpResponse = client.send(request, HttpResponse.BodyHandlers.ofString());
+      response = httpResponse.body();
+    } catch (IOException ioe) {
+      LOGGER.error("IOException Occurred", ioe);
+    } catch (InterruptedException ie) {
+      LOGGER.error("InterruptedException Occurred", ie);
+    }
+    if ("".equalsIgnoreCase(response)) {
+      return null;
+    } else {
+      return Integer.parseInt(response);
    }
-    return Integer.parseInt(response);
  }
 }
--- a/aggregator-microservices/aggregator-service/src/main/resources/application.properties
+++ b/aggregator-microservices/aggregator-service/src/main/resources/application.properties
@ -1,6 +1,6 @@
 #
 # The MIT License
-# Copyright (c) 2014 Ilkka Seppälä
+# Copyright © 2014-2019 Ilkka Seppälä
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@ -20,5 +20,4 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 #
-
 server.port=50004
--- a/aggregator-microservices/aggregator-service/src/test/java/com/iluwatar/aggregator/microservices/AggregatorTest.java
+++ b/aggregator-microservices/aggregator-service/src/test/java/com/iluwatar/aggregator/microservices/AggregatorTest.java
@ -1,17 +1,17 @@
-/**
+/*
 * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
- * <p/>
+ * Copyright © 2014-2019 Ilkka Seppälä
+ *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
- * <p/>
+ *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
- * <p/>
+ *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
@ -20,17 +20,21 @@
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
+
 package com.iluwatar.aggregator.microservices;

-import org.junit.Before;
-import org.junit.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.when;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 import org.mockito.InjectMocks;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;

-import static org.junit.Assert.assertEquals;
-import static org.mockito.Mockito.when;
-
+/**
+ * Test Aggregation of domain objects
+ */
 public class AggregatorTest {

  @InjectMocks
@ -42,7 +46,7 @@ public class AggregatorTest {
  @Mock
  private ProductInventoryClient inventoryClient;

-  @Before
+  @BeforeEach
  public void setup() {
    MockitoAnnotations.initMocks(this);
  }
@ -52,16 +56,16 @@ public class AggregatorTest {
   */
  @Test
  public void testGetProduct() {
-    String title = "The Product Title.";
-    int inventories = 5;
+    var title = "The Product Title.";
+    var inventories = 5;

    when(informationClient.getProductTitle()).thenReturn(title);
    when(inventoryClient.getProductInventories()).thenReturn(inventories);

-    Product testProduct = aggregator.getProduct();
+    var testProduct = aggregator.getProduct();

    assertEquals(title, testProduct.getTitle());
    assertEquals(inventories, testProduct.getProductInventories());
  }

-}
+}
--- a/Show More
+++ b/Show More