docs: update .all-contributorsrc [skip ci]

* add monitor design pattern .

* add extra line and change compiler version to 11 in pom.xml.

* encapsulate getBalance method .

* update puml file .

* export uml as png .

* duplicate codes eliminated .

* update tag

* change the format of pom.xml

* using logger to print

* change AtomicRefrence to type inference var

* explanations added !

* Update monitor/README.md

Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>

* Update monitor/README.md

Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>

* Update monitor/src/main/java/com/iluwatar/monitor/Main.java

Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>

* Update monitor/src/main/java/com/iluwatar/monitor/Main.java

Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>

* Update monitor/src/main/java/com/iluwatar/monitor/Main.java

Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>

* Update monitor/src/main/java/com/iluwatar/monitor/Main.java

Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>

* e.printStackTrace have changed to logger to prints standard output (STD OUT) .

* add programmatic example .

* Delete mvnw

* mvnw.cmd deleted .

* added mvnw from master

* AddUnitTest

* Add language to readme.md

Co-authored-by: Subhrodip Mohanta <subhrodipmohanta@gmail.com>
Co-authored-by: Ilkka Seppälä <iluwatar@users.noreply.github.com>
Co-authored-by: Subhrodip Mohanta <subhromo@cisco.com>
Co-authored-by: Subhrodip Mohanta <contact@subho.xyz>

.all-contributorsrc

@@ -1132,7 +1132,8 @@
       "profile": "http://subho.xyz",
       "contributions": [
         "code",
-        "review"
+        "review",
+        "maintenance"
       ]
     },
     {
@@ -1404,6 +1405,259 @@
       "contributions": [
         "translation"
       ]
+    },
+    {
+      "login": "richardmr36",
+      "name": "Martel Richard",
+      "avatar_url": "https://avatars.githubusercontent.com/u/19147333?v=4",
+      "profile": "https://github.com/richardmr36",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "va1m",
+      "name": "va1m",
+      "avatar_url": "https://avatars.githubusercontent.com/u/17025445?v=4",
+      "profile": "https://github.com/va1m",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "noamgrinch",
+      "name": "Noam Greenshtain",
+      "avatar_url": "https://avatars.githubusercontent.com/u/31648669?v=4",
+      "profile": "https://github.com/noamgrinch",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "qfxl",
+      "name": "yonghong Xu",
+      "avatar_url": "https://avatars.githubusercontent.com/u/14086462?v=4",
+      "profile": "https://xuyonghong.cn/",
+      "contributions": [
+        "doc"
+      ]
+    },
+    {
+      "login": "jinishavora",
+      "name": "jinishavora",
+      "avatar_url": "https://avatars.githubusercontent.com/u/40777762?v=4",
+      "profile": "https://www.linkedin.com/in/jinisha-vora",
+      "contributions": [
+        "review",
+        "code"
+      ]
+    },
+    {
+      "login": "eas5",
+      "name": "Elvys Soares",
+      "avatar_url": "https://avatars.githubusercontent.com/u/50836521?v=4",
+      "profile": "https://github.com/eas5",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "zWeBrain",
+      "name": "zWeBrain",
+      "avatar_url": "https://avatars.githubusercontent.com/u/46642512?v=4",
+      "profile": "https://github.com/zWeBrain",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "Al-assad",
+      "name": "余林颖",
+      "avatar_url": "https://avatars.githubusercontent.com/u/22493821?v=4",
+      "profile": "https://al-assad.github.io/notion/",
+      "contributions": [
+        "translation"
+      ]
+    },
+    {
+      "login": "STudio26",
+      "name": "Alain",
+      "avatar_url": "https://avatars.githubusercontent.com/u/6988911?v=4",
+      "profile": "https://github.com/STudio26",
+      "contributions": [
+        "translation"
+      ]
+    },
+    {
+      "login": "DEV-VRUPER",
+      "name": "VR",
+      "avatar_url": "https://avatars.githubusercontent.com/u/30525467?v=4",
+      "profile": "https://github.com/DEV-VRUPER",
+      "contributions": [
+        "doc"
+      ]
+    },
+    {
+      "login": "JackieNim",
+      "name": "JackieNim",
+      "avatar_url": "https://avatars.githubusercontent.com/u/4138836?v=4",
+      "profile": "https://github.com/JackieNim",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "EdisonE3",
+      "name": "EdisonE3",
+      "avatar_url": "https://avatars.githubusercontent.com/u/52118917?v=4",
+      "profile": "https://github.com/EdisonE3",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "tao-sun2",
+      "name": "Tao",
+      "avatar_url": "https://avatars.githubusercontent.com/u/66189688?v=4",
+      "profile": "https://github.com/tao-sun2",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "JuanManuelAbate",
+      "name": "Juan Manuel Abate",
+      "avatar_url": "https://avatars.githubusercontent.com/u/16357060?v=4",
+      "profile": "https://github.com/JuanManuelAbate",
+      "contributions": [
+        "translation"
+      ]
+    },
+    {
+      "login": "Xenilo137",
+      "name": "Xenilo137",
+      "avatar_url": "https://avatars.githubusercontent.com/u/24865069?v=4",
+      "profile": "https://github.com/Xenilo137",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "samuelpsouza",
+      "name": "Samuel Souza",
+      "avatar_url": "https://avatars.githubusercontent.com/u/17254162?v=4",
+      "profile": "https://www.linkedin.com/in/souzasamuel/",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "marlo2222",
+      "name": "Marlo Henrique",
+      "avatar_url": "https://avatars.githubusercontent.com/u/40809563?v=4",
+      "profile": "https://github.com/marlo2222",
+      "contributions": [
+        "translation"
+      ]
+    },
+    {
+      "login": "AndriyPyzh",
+      "name": "AndriyPyzh",
+      "avatar_url": "https://avatars.githubusercontent.com/u/57706635?v=4",
+      "profile": "https://github.com/AndriyPyzh",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "karthikbhat13",
+      "name": "karthikbhat13",
+      "avatar_url": "https://avatars.githubusercontent.com/u/22431014?v=4",
+      "profile": "https://github.com/karthikbhat13",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "mortezaadi",
+      "name": "Morteza Adigozalpour",
+      "avatar_url": "https://avatars.githubusercontent.com/u/1329687?v=4",
+      "profile": "https://github.com/mortezaadi",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "tan31989",
+      "name": "Nagaraj Tantri",
+      "avatar_url": "https://avatars.githubusercontent.com/u/3784194?v=4",
+      "profile": "https://stackoverflow.com/users/308565/nagaraj-tantri",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "frascu",
+      "name": "Francesco Scuccimarri",
+      "avatar_url": "https://avatars.githubusercontent.com/u/7107651?v=4",
+      "profile": "http://scuccimarri.it",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "Conhan93",
+      "name": "Conny Hansson",
+      "avatar_url": "https://avatars.githubusercontent.com/u/71334757?v=4",
+      "profile": "https://github.com/Conhan93",
+      "contributions": [
+        "doc"
+      ]
+    },
+    {
+      "login": "muklasr",
+      "name": "Muklas Rahmanto",
+      "avatar_url": "https://avatars.githubusercontent.com/u/43443753?v=4",
+      "profile": "http://muklasr.medium.com",
+      "contributions": [
+        "translation"
+      ]
+    },
+    {
+      "login": "VxDxK",
+      "name": "Vadim",
+      "avatar_url": "https://avatars.githubusercontent.com/u/38704817?v=4",
+      "profile": "https://github.com/VxDxK",
+      "contributions": [
+        "translation"
+      ]
+    },
+    {
+      "login": "sims-keshri",
+      "name": "Simran Keshri",
+      "avatar_url": "https://avatars.githubusercontent.com/u/62168475?v=4",
+      "profile": "https://github.com/sims-keshri",
+      "contributions": [
+        "code"
+      ]
+    },
+    {
+      "login": "JCarlosR",
+      "name": "JCarlos",
+      "avatar_url": "https://avatars.githubusercontent.com/u/3101238?v=4",
+      "profile": "https://programacionymas.com",
+      "contributions": [
+        "translation"
+      ]
+    },
+    {
+      "login": "Dev-AliGhasemi",
+      "name": "Ali Ghasemi",
+      "avatar_url": "https://avatars.githubusercontent.com/u/60359433?v=4",
+      "profile": "https://www.mrmoshkel.ir",
+      "contributions": [
+        "code"
+      ]
     }
   ],
   "contributorsPerLine": 4,

.circleci/config.yml

@@ -0,0 +1,52 @@
+#
+# The MIT License
+# Copyright © 2014-2021 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.
+#
+
+version: 2
+
+jobs:
+  sonar-pr:
+    docker:
+      - image: circleci/openjdk:11-node
+    steps:
+    - checkout
+    - restore_cache:
+        key: jdp-sonar-pr-{{ checksum "pom.xml" }}
+    - run: |
+        if [ -n "${CIRCLE_PR_NUMBER}" ]; then
+          MAVEN_OPTS="-Xmx3000m" xvfb-run ./mvnw -B clean verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonar \
+             -Dsonar.pullrequest.key=${CIRCLE_PR_NUMBER} \
+             -Dsonar.pullrequest.branch=${CIRCLE_BRANCH} \
+             -Dsonar.pullrequest.base=master
+        else
+          echo "No Sonar PR analysis as this is not a pull request"
+        fi
+    - save_cache:
+        key: jdp-sonar-pr-{{ checksum "pom.xml" }}
+        paths:
+        - ~/.m2
+
+workflows:
+  version: 2
+  all:
+    jobs:
+    - sonar-pr

.github/workflows/maven-ci.yml

@@ -46,9 +46,10 @@ jobs:
         fetch-depth: 0
 
     - name: Set up JDK 11
-      uses: actions/setup-java@v1
+      uses: actions/setup-java@v2
       with:
         java-version: 11
+        distribution: 'adopt'
 
     - name: Cache SonarCloud packages
       uses: actions/cache@v2
@@ -69,9 +70,6 @@ jobs:
     - name: Install xvfb
       run: sudo apt-get install -y xvfb
 
-    # The SonarQube analysis is only for the master branch of the main repository.
-    # SonarQube scan does not work for forked repositories try changing it to xvfb-run mvn clean verify
-    # See https://jira.sonarsource.com/browse/MMF-1371
     - name: Build with Maven and run SonarQube analysis
       run: xvfb-run ./mvnw clean verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonar
       env:

.github/workflows/maven-pr-builder.yml

@@ -29,7 +29,7 @@ name: Java PR Builder
 on:
   pull_request:
     branches: [ master ]
-    types: [ opened, reopened, synchronize, labeled, unlabeled ]
+    types: [ opened, reopened, synchronize ]
 
 jobs:
   build:
@@ -41,9 +41,10 @@ jobs:
       uses: actions/checkout@v2
     
     - name: Set up JDK 11
-      uses: actions/setup-java@v1
+      uses: actions/setup-java@v2
       with:
         java-version: 11
+        distribution: 'adopt'
     
     - name: Cache Maven Dependecies
       uses: actions/cache@v2
@@ -57,8 +58,5 @@ jobs:
     - name: Install xvfb
       run: sudo apt-get install -y xvfb
     
-    # This worflow is only for building Pull Requests, the master branch runs Sonar analysis on the main repository.
-    # SonarQube scan does not work for forked repositories.
-    # See https://jira.sonarsource.com/browse/MMF-1371
     - name: Build with Maven
       run: xvfb-run ./mvnw clean verify

.mvn/wrapper/MavenWrapperDownloader.java

@@ -1,18 +1,26 @@
 /*
- * Copyright 2007-present the original author or authors.
+ * The MIT License
+ * Copyright © 2014-2021 Ilkka Seppälä
  *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
+ * 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:
  *
- *      http://www.apache.org/licenses/LICENSE-2.0
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
  *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ * 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 java.net.*;
 import java.io.*;
 import java.nio.channels.*;

LICENSE.md

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2014-2021 Ilkka Seppälä
+Copyright <EFBFBD> 2014-2021 Ilkka Sepp<EFBFBD>l<EFBFBD>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -19,3 +19,6 @@ 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 Model-view-viewmodel is using ZK framework
+ZK framework is licensed under LGPL and the license can be found at lgpl-3.0.txt

README.md

@@ -4,18 +4,18 @@
 
 # Design patterns implemented in Java
 
-![Java CI with Maven](https://github.com/iluwatar/java-design-patterns/workflows/Java%20CI%20with%20Maven/badge.svg)
+![Java CI](https://github.com/iluwatar/java-design-patterns/workflows/Java%20CI/badge.svg)
 [![License MIT](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/iluwatar/java-design-patterns/master/LICENSE.md)
-[![Lines of Code](https://sonarcloud.io/api/project_badges/measure?project=iluwatar_java-design-patterns&metric=ncloc)](https://sonarcloud.io/dashboard?id=iluwatar_java-design-patterns) 
+[![Lines of Code](https://sonarcloud.io/api/project_badges/measure?project=iluwatar_java-design-patterns&metric=ncloc)](https://sonarcloud.io/dashboard?id=iluwatar_java-design-patterns)
 [![Coverage](https://sonarcloud.io/api/project_badges/measure?project=iluwatar_java-design-patterns&metric=coverage)](https://sonarcloud.io/dashboard?id=iluwatar_java-design-patterns)
 [![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)
 <!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
-[![All Contributors](https://img.shields.io/badge/all_contributors-154-orange.svg?style=flat-square)](#contributors-)
+[![All Contributors](https://img.shields.io/badge/all_contributors-182-orange.svg?style=flat-square)](#contributors-)
 <!-- ALL-CONTRIBUTORS-BADGE:END -->
 
 <br/>
 
-Read in different language : [![CN](/assets/flags/CN.png)**CN**](/zh/README.md),[![KR](/assets/flags/KR.png)**KR**](/ko/README.md),[![FR](/assets/flags/FR.png)**FR**](/fr/README.md),[![TR](/assets/flags/TR.png)**TR**](/tr/README.md),[![AR](/assets/flags/AR.png)**AR**](/ar/README.md),
+Read in different language : [**zh**](localization/zh/README.md), [**ko**](localization/ko/README.md), [**fr**](localization/fr/README.md), [**tr**](localization/tr/README.md), [**ar**](localization/ar/README.md), [**es**](localization/es/README.md), [**pt**](localization/pt/README.md), [**id**](localization/id/README.md), [**ru**](localization/ru/README.md) 
 
 <br/>
 
@@ -34,7 +34,7 @@ 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 
+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 on how to implement a specific pattern. We use the most
@@ -49,7 +49,7 @@ 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 the
-[available design patterns](https://java-design-patterns.com/patterns/) by any 
+[available design patterns](https://java-design-patterns.com/patterns/) by any
 of the following approaches
 
  - 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).
@@ -61,8 +61,8 @@ in your architectures and have as much fun learning them as we had developing th
 
 # 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 
+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
@@ -259,7 +259,7 @@ This project is licensed under the terms of the MIT license.
     <td align="center"><a href="https://www.linkedin.com/in/ashish-trivedi-218379135/"><img src="https://avatars3.githubusercontent.com/u/23194128?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Ashish Trivedi</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ashishtrivedi16" title="Code">💻</a></td>
     <td align="center"><a href="https://rayyounghong.com"><img src="https://avatars1.githubusercontent.com/u/41055099?v=4?s=100" width="100px;" alt=""/><br /><sub><b>洪月阳</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=RayYH" title="Code">💻</a></td>
     <td align="center"><a href="https://xdvrx1.github.io/"><img src="https://avatars0.githubusercontent.com/u/47092464?v=4?s=100" width="100px;" alt=""/><br /><sub><b>xdvrx1</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Axdvrx1" title="Reviewed Pull Requests">👀</a> <a href="#ideas-xdvrx1" title="Ideas, Planning, & Feedback">🤔</a></td>
-    <td align="center"><a href="http://subho.xyz"><img src="https://avatars0.githubusercontent.com/u/13291222?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Subhrodip Mohanta</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ohbus" title="Code">💻</a> <a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Aohbus" title="Reviewed Pull Requests">👀</a></td>
+    <td align="center"><a href="http://subho.xyz"><img src="https://avatars0.githubusercontent.com/u/13291222?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Subhrodip Mohanta</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=ohbus" title="Code">💻</a> <a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Aohbus" title="Reviewed Pull Requests">👀</a> <a href="#maintenance-ohbus" title="Maintenance">🚧</a></td>
   </tr>
   <tr>
     <td align="center"><a href="https://github.com/nahteb"><img src="https://avatars3.githubusercontent.com/u/13121570?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Bethan Palmer</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=nahteb" title="Code">💻</a></td>
@@ -306,6 +306,48 @@ This project is licensed under the terms of the MIT license.
   <tr>
     <td align="center"><a href="https://github.com/byoungju94"><img src="https://avatars.githubusercontent.com/u/42516378?v=4?s=100" width="100px;" alt=""/><br /><sub><b>byoungju94</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=byoungju94" title="Code">💻</a></td>
     <td align="center"><a href="https://github.com/moustafafarhat"><img src="https://avatars.githubusercontent.com/u/38836727?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Moustafa Farhat</b></sub></a><br /><a href="#translation-moustafafarhat" title="Translation">🌍</a></td>
+    <td align="center"><a href="https://github.com/richardmr36"><img src="https://avatars.githubusercontent.com/u/19147333?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Martel Richard</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=richardmr36" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/va1m"><img src="https://avatars.githubusercontent.com/u/17025445?v=4?s=100" width="100px;" alt=""/><br /><sub><b>va1m</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=va1m" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/noamgrinch"><img src="https://avatars.githubusercontent.com/u/31648669?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Noam Greenshtain</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=noamgrinch" title="Code">💻</a></td>
+    <td align="center"><a href="https://xuyonghong.cn/"><img src="https://avatars.githubusercontent.com/u/14086462?v=4?s=100" width="100px;" alt=""/><br /><sub><b>yonghong Xu</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=qfxl" title="Documentation">📖</a></td>
+    <td align="center"><a href="https://www.linkedin.com/in/jinisha-vora"><img src="https://avatars.githubusercontent.com/u/40777762?v=4?s=100" width="100px;" alt=""/><br /><sub><b>jinishavora</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/pulls?q=is%3Apr+reviewed-by%3Ajinishavora" title="Reviewed Pull Requests">👀</a> <a href="https://github.com/iluwatar/java-design-patterns/commits?author=jinishavora" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/eas5"><img src="https://avatars.githubusercontent.com/u/50836521?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Elvys Soares</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=eas5" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/zWeBrain"><img src="https://avatars.githubusercontent.com/u/46642512?v=4?s=100" width="100px;" alt=""/><br /><sub><b>zWeBrain</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=zWeBrain" title="Code">💻</a></td>
+    <td align="center"><a href="https://al-assad.github.io/notion/"><img src="https://avatars.githubusercontent.com/u/22493821?v=4?s=100" width="100px;" alt=""/><br /><sub><b>余林颖</b></sub></a><br /><a href="#translation-Al-assad" title="Translation">🌍</a></td>
+    <td align="center"><a href="https://github.com/STudio26"><img src="https://avatars.githubusercontent.com/u/6988911?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Alain</b></sub></a><br /><a href="#translation-STudio26" title="Translation">🌍</a></td>
+    <td align="center"><a href="https://github.com/DEV-VRUPER"><img src="https://avatars.githubusercontent.com/u/30525467?v=4?s=100" width="100px;" alt=""/><br /><sub><b>VR</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=DEV-VRUPER" title="Documentation">📖</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/JackieNim"><img src="https://avatars.githubusercontent.com/u/4138836?v=4?s=100" width="100px;" alt=""/><br /><sub><b>JackieNim</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=JackieNim" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/EdisonE3"><img src="https://avatars.githubusercontent.com/u/52118917?v=4?s=100" width="100px;" alt=""/><br /><sub><b>EdisonE3</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=EdisonE3" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/tao-sun2"><img src="https://avatars.githubusercontent.com/u/66189688?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Tao</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=tao-sun2" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/JuanManuelAbate"><img src="https://avatars.githubusercontent.com/u/16357060?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Juan Manuel Abate</b></sub></a><br /><a href="#translation-JuanManuelAbate" title="Translation">🌍</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/Xenilo137"><img src="https://avatars.githubusercontent.com/u/24865069?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Xenilo137</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Xenilo137" title="Code">💻</a></td>
+    <td align="center"><a href="https://www.linkedin.com/in/souzasamuel/"><img src="https://avatars.githubusercontent.com/u/17254162?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Samuel Souza</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=samuelpsouza" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/marlo2222"><img src="https://avatars.githubusercontent.com/u/40809563?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Marlo Henrique</b></sub></a><br /><a href="#translation-marlo2222" title="Translation">🌍</a></td>
+    <td align="center"><a href="https://github.com/AndriyPyzh"><img src="https://avatars.githubusercontent.com/u/57706635?v=4?s=100" width="100px;" alt=""/><br /><sub><b>AndriyPyzh</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=AndriyPyzh" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/karthikbhat13"><img src="https://avatars.githubusercontent.com/u/22431014?v=4?s=100" width="100px;" alt=""/><br /><sub><b>karthikbhat13</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=karthikbhat13" title="Code">💻</a></td>
+    <td align="center"><a href="https://github.com/mortezaadi"><img src="https://avatars.githubusercontent.com/u/1329687?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Morteza Adigozalpour</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=mortezaadi" title="Code">💻</a></td>
+    <td align="center"><a href="https://stackoverflow.com/users/308565/nagaraj-tantri"><img src="https://avatars.githubusercontent.com/u/3784194?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Nagaraj Tantri</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=tan31989" title="Code">💻</a></td>
+    <td align="center"><a href="http://scuccimarri.it"><img src="https://avatars.githubusercontent.com/u/7107651?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Francesco Scuccimarri</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=frascu" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://github.com/Conhan93"><img src="https://avatars.githubusercontent.com/u/71334757?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Conny Hansson</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Conhan93" title="Documentation">📖</a></td>
+    <td align="center"><a href="http://muklasr.medium.com"><img src="https://avatars.githubusercontent.com/u/43443753?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Muklas Rahmanto</b></sub></a><br /><a href="#translation-muklasr" title="Translation">🌍</a></td>
+    <td align="center"><a href="https://github.com/VxDxK"><img src="https://avatars.githubusercontent.com/u/38704817?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Vadim</b></sub></a><br /><a href="#translation-VxDxK" title="Translation">🌍</a></td>
+    <td align="center"><a href="https://github.com/sims-keshri"><img src="https://avatars.githubusercontent.com/u/62168475?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Simran Keshri</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=sims-keshri" title="Code">💻</a></td>
+  </tr>
+  <tr>
+    <td align="center"><a href="https://programacionymas.com"><img src="https://avatars.githubusercontent.com/u/3101238?v=4?s=100" width="100px;" alt=""/><br /><sub><b>JCarlos</b></sub></a><br /><a href="#translation-JCarlosR" title="Translation">🌍</a></td>
+    <td align="center"><a href="https://www.mrmoshkel.ir"><img src="https://avatars.githubusercontent.com/u/60359433?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Ali Ghasemi</b></sub></a><br /><a href="https://github.com/iluwatar/java-design-patterns/commits?author=Dev-AliGhasemi" title="Code">💻</a></td>
   </tr>
 </table>
 

abstract-document/README.md

@@ -4,6 +4,7 @@ title: Abstract Document
 folder: abstract-document
 permalink: /patterns/abstract-document/
 categories: Structural
+language: en
 tags: 
  - Extensibility
 ---

abstract-document/pom.xml

@@ -30,7 +30,7 @@
 	<parent>
 		<artifactId>java-design-patterns</artifactId>
 		<groupId>com.iluwatar</groupId>
-		<version>1.24.0-SNAPSHOT</version>
+		<version>1.25.0-SNAPSHOT</version>
 	</parent>
 	<artifactId>abstract-document</artifactId>
 	<dependencies>

abstract-document/src/main/java/com/iluwatar/abstractdocument/App.java

@@ -27,8 +27,7 @@ import com.iluwatar.abstractdocument.domain.Car;
 import com.iluwatar.abstractdocument.domain.enums.Property;
 import java.util.List;
 import java.util.Map;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * The Abstract Document pattern enables handling additional, non-static properties. This pattern
@@ -38,10 +37,9 @@ import org.slf4j.LoggerFactory;
  * <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.
  */
+@Slf4j
 public class App {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
-
   /**
    * Program entry point.
    *

abstract-document/src/test/java/com/iluwatar/abstractdocument/AbstractDocumentTest.java

@@ -23,19 +23,18 @@
 
 package com.iluwatar.abstractdocument;
 
-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 org.junit.jupiter.api.Test;
 
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
 
 /**
  * AbstractDocument test class
  */
-public class AbstractDocumentTest {
+class AbstractDocumentTest {
 
   private static final String KEY = "key";
   private static final String VALUE = "value";
@@ -50,13 +49,13 @@ public class AbstractDocumentTest {
   private final DocumentImplementation document = new DocumentImplementation(new HashMap<>());
 
   @Test
-  public void shouldPutAndGetValue() {
+  void shouldPutAndGetValue() {
     document.put(KEY, VALUE);
     assertEquals(VALUE, document.get(KEY));
   }
 
   @Test
-  public void shouldRetrieveChildren() {
+  void shouldRetrieveChildren() {
     var children = List.of(Map.of(), Map.of());
 
     document.put(KEY, children);
@@ -67,14 +66,14 @@ public class AbstractDocumentTest {
   }
 
   @Test
-  public void shouldRetrieveEmptyStreamForNonExistingChildren() {
+  void shouldRetrieveEmptyStreamForNonExistingChildren() {
     var children = document.children(KEY, DocumentImplementation::new);
     assertNotNull(children);
     assertEquals(0, children.count());
   }
 
   @Test
-  public void shouldIncludePropsInToString() {
+  void shouldIncludePropsInToString() {
     var props = Map.of(KEY, (Object) VALUE);
     var document = new DocumentImplementation(props);
     assertTrue(document.toString().contains(KEY));

abstract-document/src/test/java/com/iluwatar/abstractdocument/DomainTest.java

@@ -23,19 +23,20 @@
 
 package com.iluwatar.abstractdocument;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 import com.iluwatar.abstractdocument.domain.Car;
 import com.iluwatar.abstractdocument.domain.Part;
 import com.iluwatar.abstractdocument.domain.enums.Property;
+import org.junit.jupiter.api.Test;
+
 import java.util.List;
 import java.util.Map;
-import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 /**
  * Test for Part and Car
  */
-public class DomainTest {
+class DomainTest {
 
   private static final String TEST_PART_TYPE = "test-part-type";
   private static final String TEST_PART_MODEL = "test-part-model";
@@ -45,7 +46,7 @@ public class DomainTest {
   private static final long TEST_CAR_PRICE = 1L;
 
   @Test
-  public void shouldConstructPart() {
+  void shouldConstructPart() {
     var partProperties = Map.of(
         Property.TYPE.toString(), TEST_PART_TYPE,
         Property.MODEL.toString(), TEST_PART_MODEL,
@@ -58,7 +59,7 @@ public class DomainTest {
   }
 
   @Test
-  public void shouldConstructCar() {
+  void shouldConstructCar() {
     var carProperties = Map.of(
         Property.MODEL.toString(), TEST_CAR_MODEL,
         Property.PRICE.toString(), TEST_CAR_PRICE,

abstract-factory/README.md

@@ -4,6 +4,7 @@ title: Abstract Factory
 folder: abstract-factory
 permalink: /patterns/abstract-factory/
 categories: Creational
+language: en
 tags:
  - Gang of Four
 ---
@@ -19,9 +20,9 @@ objects without specifying their concrete classes.
 
 ## Explanation
 
-Real world example
+Real-world example
 
-> To create a kingdom we need objects with a 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.
+> To create a kingdom we need objects with a common theme. The elven kingdom needs an elven king, elven castle, and elven army whereas the orcish kingdom needs an orcish king, orcish castle, and orcish army. There is a dependency between the objects in the kingdom.
 
 In plain words
 
@@ -33,7 +34,7 @@ Wikipedia says
 
 **Programmatic Example**
 
-Translating the kingdom example above. First of all we have some interfaces and implementation for the objects in the 
+Translating the kingdom example above. First of all, we have some interfaces and implementation for the objects in the 
 kingdom.
 
 ```java
@@ -51,21 +52,21 @@ public interface Army {
 
 // Elven implementations ->
 public class ElfCastle implements Castle {
-  static final String DESCRIPTION = "This is the Elven 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!";
+  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!";
+  static final String DESCRIPTION = "This is the elven Army!";
   @Override
   public String getDescription() {
     return DESCRIPTION;
@@ -76,7 +77,7 @@ public class ElfArmy implements Army {
 
 ```
 
-Then we have the abstraction and implementations for the kingdom factory
+Then we have the abstraction and implementations for the kingdom factory.
 
 ```java
 public interface KingdomFactory {
@@ -110,7 +111,7 @@ public class OrcKingdomFactory implements KingdomFactory {
 }
 ```
 
-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.
+Now we have the abstract factory that lets us make a family of related objects i.e. elven kingdom factory creates elven castle, king and army, etc.
 
 ```java
 var factory = new ElfKingdomFactory();
@@ -126,13 +127,13 @@ army.getDescription();
 Program output:
 
 ```java
-This is the Elven castle!
-This is the Elven king!
-This is the Elven Army!
+This is the elven castle!
+This is the elven king!
+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).  
+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 (derived from `Army`, `King`, `Castle`).  
 In this example, we also used an enum to parameterize which type of kingdom factory the client will ask for.
 
 ```java
@@ -178,8 +179,8 @@ public static void main(String[] args) {
 
 Use the Abstract Factory pattern when
 
-* The system should be independent of how its products are created, composed and represented
-* The system should be configured with one of multiple families of products
+* The system should be independent of how its products are created, composed, and represented
+* The system should be configured with one of the multiple families of products
 * The 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.
@@ -195,13 +196,13 @@ Example use cases
 * Unit test case writing becomes much easier
 * UI tools for different OS
 
-## Consequences:
+## 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 becomes more complicated than it should be, since a lot of new interfaces and classes are introduced along with the pattern.
+* The code becomes more complicated than it should be since a lot of new interfaces and classes are introduced along with the pattern.
 
-## Tutorial
+## Tutorials
 
 * [Abstract Factory Pattern Tutorial](https://www.journaldev.com/1418/abstract-factory-design-pattern-in-java) 
 

abstract-factory/pom.xml

@@ -31,7 +31,7 @@
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-		<version>1.24.0-SNAPSHOT</version>
+		<version>1.25.0-SNAPSHOT</version>
 	</parent>
 	<artifactId>abstract-factory</artifactId>
 	<dependencies>

abstract-factory/src/main/java/com/iluwatar/abstractfactory/App.java

@@ -23,8 +23,7 @@
 
 package com.iluwatar.abstractfactory;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * The Abstract Factory pattern provides a way to encapsulate a group of individual factories that
@@ -38,12 +37,11 @@ import org.slf4j.LoggerFactory;
  *
  * <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.
+ * both concrete implementations to create a king, a castle, and an army.
  */
+@Slf4j
 public class App implements Runnable {
 
-  private static Logger log = LoggerFactory.getLogger(App.class);
-
   private final Kingdom kingdom = new Kingdom();
 
   public Kingdom getKingdom() {
@@ -62,17 +60,17 @@ public class App implements Runnable {
 
   @Override
   public void run() {
-    log.info("Elf Kingdom");
+    LOGGER.info("elf kingdom");
     createKingdom(Kingdom.FactoryMaker.KingdomType.ELF);
-    log.info(kingdom.getArmy().getDescription());
-    log.info(kingdom.getCastle().getDescription());
-    log.info(kingdom.getKing().getDescription());
+    LOGGER.info(kingdom.getArmy().getDescription());
+    LOGGER.info(kingdom.getCastle().getDescription());
+    LOGGER.info(kingdom.getKing().getDescription());
 
-    log.info("Orc Kingdom");
+    LOGGER.info("orc kingdom");
     createKingdom(Kingdom.FactoryMaker.KingdomType.ORC);
-    log.info(kingdom.getArmy().getDescription());
-    log.info(kingdom.getCastle().getDescription());
-    log.info(kingdom.getKing().getDescription());
+    LOGGER.info(kingdom.getArmy().getDescription());
+    LOGGER.info(kingdom.getCastle().getDescription());
+    LOGGER.info(kingdom.getKing().getDescription());
   }
 
   /**

abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfArmy.java

@@ -28,7 +28,7 @@ package com.iluwatar.abstractfactory;
  */
 public class ElfArmy implements Army {
 
-  static final String DESCRIPTION = "This is the Elven Army!";
+  static final String DESCRIPTION = "This is the elven army!";
 
   @Override
   public String getDescription() {

abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfCastle.java

@@ -28,7 +28,7 @@ package com.iluwatar.abstractfactory;
  */
 public class ElfCastle implements Castle {
 
-  static final String DESCRIPTION = "This is the Elven castle!";
+  static final String DESCRIPTION = "This is the elven castle!";
 
   @Override
   public String getDescription() {

abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKing.java

@@ -28,7 +28,7 @@ package com.iluwatar.abstractfactory;
  */
 public class ElfKing implements King {
 
-  static final String DESCRIPTION = "This is the Elven king!";
+  static final String DESCRIPTION = "This is the elven king!";
 
   @Override
   public String getDescription() {

abstract-factory/src/main/java/com/iluwatar/abstractfactory/Kingdom.java

@@ -23,36 +23,17 @@
 
 package com.iluwatar.abstractfactory;
 
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
 public class Kingdom {
 
   private King king;
   private Castle castle;
   private Army army;
 
-  public King getKing() {
-    return king;
-  }
-
-  public Castle getCastle() {
-    return castle;
-  }
-
-  public Army getArmy() {
-    return army;
-  }
-
-  public void setKing(King king) {
-    this.king = king;
-  }
-
-  public void setCastle(Castle castle) {
-    this.castle = castle;
-  }
-
-  public void setArmy(Army army) {
-    this.army = army;
-  }
-
   /**
    * The factory of kingdom factories.
    */

abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcArmy.java

@@ -28,7 +28,7 @@ package com.iluwatar.abstractfactory;
  */
 public class OrcArmy implements Army {
 
-  static final String DESCRIPTION = "This is the Orc Army!";
+  static final String DESCRIPTION = "This is the orc army!";
 
   @Override
   public String getDescription() {

abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcCastle.java

@@ -28,7 +28,7 @@ package com.iluwatar.abstractfactory;
  */
 public class OrcCastle implements Castle {
 
-  static final String DESCRIPTION = "This is the Orc castle!";
+  static final String DESCRIPTION = "This is the orc castle!";
 
   @Override
   public String getDescription() {

abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKing.java

@@ -28,7 +28,7 @@ package com.iluwatar.abstractfactory;
  */
 public class OrcKing implements King {
 
-  static final String DESCRIPTION = "This is the Orc king!";
+  static final String DESCRIPTION = "This is the orc king!";
 
   @Override
   public String getDescription() {

abstract-factory/src/test/java/com/iluwatar/abstractfactory/AbstractFactoryTest.java

@@ -29,14 +29,14 @@ import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 /**
- * Test for abstract factory.
+ * Tests for abstract factory.
  */
-public class AbstractFactoryTest {
+class AbstractFactoryTest {
 
   private final App app = new App();
 
   @Test
-  public void king() {
+  void verifyKingCreation() {
     app.createKingdom(Kingdom.FactoryMaker.KingdomType.ELF);
     final var kingdom = app.getKingdom();
 
@@ -51,7 +51,7 @@ public class AbstractFactoryTest {
   }
 
   @Test
-  public void castle() {
+  void verifyCastleCreation() {
     app.createKingdom(Kingdom.FactoryMaker.KingdomType.ELF);
     final var kingdom = app.getKingdom();
 
@@ -66,7 +66,7 @@ public class AbstractFactoryTest {
   }
 
   @Test
-  public void army() {
+  void verifyArmyCreation() {
     app.createKingdom(Kingdom.FactoryMaker.KingdomType.ELF);
     final var kingdom = app.getKingdom();
 
@@ -81,7 +81,7 @@ public class AbstractFactoryTest {
   }
 
   @Test
-  public void createElfKingdom() {
+  void verifyElfKingdomCreation() {
     app.createKingdom(Kingdom.FactoryMaker.KingdomType.ELF);
     final var kingdom = app.getKingdom();
 
@@ -97,7 +97,7 @@ public class AbstractFactoryTest {
   }
 
   @Test
-  public void createOrcKingdom() {
+  void verifyOrcKingdomCreation() {
     app.createKingdom(Kingdom.FactoryMaker.KingdomType.ORC);
     final var kingdom = app.getKingdom();
 

abstract-factory/src/test/java/com/iluwatar/abstractfactory/AppTest.java

@@ -28,20 +28,13 @@ import org.junit.jupiter.api.Test;
 import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
 
 /**
- * Tests that Abstract Factory example runs without errors.
+ * Check whether the execution of the main method in {@link App} throws an exception.
  */
 class AppTest {
-
-  /**
-   * Issue: Add at least one assertion to this test case.
-   *
-   * Solution: Inserted assertion to check whether the execution of the main method in {@link App}
-   * throws an exception.
-   */
-
+    
   @Test
   void shouldExecuteApplicationWithoutException() {
 
-    assertDoesNotThrow(() -> App.main(new String[]{}));
+	  assertDoesNotThrow(() -> App.main(new String[]{}));
   }
 }

active-object/README.md

@@ -0,0 +1,126 @@
+---
+layout: pattern
+title: Active Object
+folder: active-object
+permalink: /patterns/active-object/
+categories: Concurrency
+language: en
+tags:
+ - Performance
+---
+
+
+## Intent
+The active object design pattern decouples method execution from method invocation for objects that each reside in their thread of control. The goal is to introduce concurrency, by using asynchronous method invocation, and a scheduler for handling requests.
+
+## Explanation
+
+The class that implements the active object pattern will contain a self-synchronization mechanism without using 'synchronized' methods.
+
+Real-world example
+
+>The Orcs are known for their wildness and untameable soul. It seems like they have their own thread of control based on previous behavior.
+
+To implement a creature that has its own thread of control mechanism and expose its API only and not the execution itself, we can use the Active Object pattern.
+
+
+**Programmatic Example**
+
+```java
+public abstract class ActiveCreature{
+  private final Logger logger = LoggerFactory.getLogger(ActiveCreature.class.getName());
+
+  private BlockingQueue<Runnable> requests;
+  
+  private String name;
+  
+  private Thread thread;
+
+  public ActiveCreature(String name) {
+    this.name = name;
+    this.requests = new LinkedBlockingQueue<Runnable>();
+    thread = new Thread(new Runnable() {
+        @Override
+        public void run() {
+          while (true) {
+            try {
+              requests.take().run();
+            } catch (InterruptedException e) { 
+              logger.error(e.getMessage());
+            }
+          }
+        }
+      }
+    );
+    thread.start();
+  }
+  
+  public void eat() throws InterruptedException {
+    requests.put(new Runnable() {
+        @Override
+        public void run() { 
+          logger.info("{} is eating!",name());
+          logger.info("{} has finished eating!",name());
+        }
+      }
+    );
+  }
+
+  public void roam() throws InterruptedException {
+    requests.put(new Runnable() {
+        @Override
+        public void run() { 
+          logger.info("{} has started to roam the wastelands.",name());
+        }
+      }
+    );
+  }
+  
+  public String name() {
+    return this.name;
+  }
+}
+```
+
+We can see that any class that will extend the ActiveCreature class will have its own thread of control to invoke and execute methods.
+
+For example, the Orc class:
+
+```java
+public class Orc extends ActiveCreature {
+
+  public Orc(String name) {
+    super(name);
+  }
+
+}
+```
+
+Now, we can create multiple creatures such as Orcs, tell them to eat and roam, and they will execute it on their own thread of control:
+
+```java
+  public static void main(String[] args) {  
+    var app = new App();
+    app.run();
+  }
+  
+  @Override
+  public void run() {
+    ActiveCreature creature;
+    try {
+      for (int i = 0;i < creatures;i++) {
+        creature = new Orc(Orc.class.getSimpleName().toString() + i);
+        creature.eat();
+        creature.roam();
+      }
+      Thread.sleep(1000);
+    } catch (InterruptedException e) {
+      logger.error(e.getMessage());
+    }
+    Runtime.getRuntime().exit(1);
+  }
+```
+
+## Class diagram
+
+![alt text](./etc/active-object.urm.png "Active Object class diagram")

active-object/etc/active-object.urm.puml

@@ -0,0 +1,25 @@
+@startuml
+package com.iluwatar.activeobject {
+  abstract class ActiveCreature {
+    - logger : Logger
+    - name : String
+    - requests : BlockingQueue<Runnable>
+    - thread : Thread
+    + ActiveCreature(name : String)
+    + eat()
+    + name() : String
+    + roam()
+  }
+  class App {
+    - creatures : Integer
+    - logger : Logger
+    + App()
+    + main(args : String[]) {static}
+    + run()
+  }
+  class Orc {
+    + Orc(name : String)
+  }
+}
+Orc --|> ActiveCreature 
+@enduml

active-object/pom.xml

@@ -0,0 +1,65 @@
+<?xml version="1.0"?>
+<!--
+
+    The MIT License
+    Copyright © 2014-2021 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>1.25.0-SNAPSHOT</version>
+	</parent>
+	<artifactId>active-object</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.activeobject.App</mainClass>
+								</manifest>
+							</archive>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+		</plugins>
+	</build>
+</project>

active-object/src/main/java/com/iluwatar/activeobject/ActiveCreature.java

@@ -0,0 +1,118 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2021 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.activeobject;
+
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.LinkedBlockingQueue;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * ActiveCreature class is the base of the active object example.
+ * @author Noam Greenshtain
+ *
+ */
+public abstract class ActiveCreature {
+  
+  private static final Logger logger = LoggerFactory.getLogger(ActiveCreature.class.getName());
+
+  private BlockingQueue<Runnable> requests;
+  
+  private String name;
+  
+  private Thread thread; // Thread of execution.
+  
+  private int status; // status of the thread of execution.
+
+  /**
+   * Constructor and initialization.
+   */
+  protected ActiveCreature(String name) {
+    this.name = name;
+    this.status = 0;
+    this.requests = new LinkedBlockingQueue<>();
+    thread = new Thread(() -> {
+      boolean infinite = true;
+      while (infinite) {
+        try {
+          requests.take().run();
+        } catch (InterruptedException e) {
+          if (this.status != 0) {
+            logger.error("Thread was interrupted. --> {}", e.getMessage()); 
+          }
+          infinite = false;
+          Thread.currentThread().interrupt();
+        }
+      }
+    });
+    thread.start();
+  }
+
+  /**
+   * Eats the porridge.
+   * @throws InterruptedException due to firing a new Runnable.
+   */
+  public void eat() throws InterruptedException {
+    requests.put(() -> {
+      logger.info("{} is eating!",name());
+      logger.info("{} has finished eating!",name());
+    });
+  }
+
+  /**
+   * Roam the wastelands.
+   * @throws InterruptedException due to firing a new Runnable.
+   */
+  public void roam() throws InterruptedException {
+    requests.put(() ->
+        logger.info("{} has started to roam in the wastelands.",name())
+    );
+  }
+  
+  /**
+   * Returns the name of the creature.
+   * @return the name of the creature.
+   */
+  public String name() {
+    return this.name;
+  }
+  
+  /**
+   * Kills the thread of execution.
+   * @param status of the thread of execution. 0 == OK, the rest is logging an error.
+   */
+  public void kill(int status) {
+    this.status = status;
+    this.thread.interrupt();
+  }
+  
+  /**
+   * Returns the status of the thread of execution.
+   * @return the status of the thread of execution.
+   */
+  public int getStatus() {
+    return this.status;
+  }
+}

active-object/src/main/java/com/iluwatar/activeobject/App.java

@@ -0,0 +1,75 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2021 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.activeobject;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * The Active Object pattern helps to solve synchronization difficulties without using 
+ * 'synchronized' methods. The active object will contain a thread-safe data structure 
+ * (such as BlockingQueue) and use to synchronize method calls by moving the logic of the method
+ * into an invocator(usually a Runnable) and store it in the DSA.
+ * 
+ * <p>In this example, we fire 20 threads to modify a value in the target class.
+ */
+public class App implements Runnable {
+  
+  private static final Logger logger = LoggerFactory.getLogger(App.class.getName());
+  
+  private static final int NUM_CREATURES = 3;
+
+  /**
+   * Program entry point.
+   *
+   * @param args command line arguments.
+   */
+  public static void main(String[] args) {  
+    var app = new App();
+    app.run();
+  }
+  
+  @Override
+  public void run() {
+    List<ActiveCreature> creatures = new ArrayList<>();
+    try {
+      for (int i = 0;i < NUM_CREATURES;i++) {
+        creatures.add(new Orc(Orc.class.getSimpleName() + i));
+        creatures.get(i).eat();
+        creatures.get(i).roam();
+      }
+      Thread.sleep(1000);
+    } catch (InterruptedException e) {
+      logger.error(e.getMessage());
+      Thread.currentThread().interrupt();
+    } finally {
+      for (int i = 0;i < NUM_CREATURES;i++) {
+        creatures.get(i).kill(0);
+      }
+    }
+  }
+}

active-object/src/main/java/com/iluwatar/activeobject/Orc.java

@@ -0,0 +1,37 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2021 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.activeobject;
+
+/**
+ * An implementation of the ActiveCreature class.
+ * @author Noam Greenshtain
+ *
+ */
+public class Orc extends ActiveCreature {
+
+  public Orc(String name) {
+    super(name);
+  }
+
+}

active-object/src/test/java/com/iluwatar/activeobject/ActiveCreatureTest.java

@@ -0,0 +1,42 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2021 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.activeobject;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+class ActiveCreatureTest {
+	
+	@Test
+	void executionTest() throws InterruptedException {
+		ActiveCreature orc = new Orc("orc1");
+		assertEquals("orc1",orc.name());
+		assertEquals(0,orc.getStatus());
+		orc.eat();
+		orc.roam();
+		orc.kill(0);
+	}
+	
+
+}

active-object/src/test/java/com/iluwatar/activeobject/AppTest.java

@@ -0,0 +1,37 @@
+/*
+ * The MIT License
+ * Copyright © 2014-2021 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.activeobject;
+
+import static org.junit.jupiter.api.Assertions.assertDoesNotThrow;
+
+import org.junit.jupiter.api.Test;
+
+
+class AppTest {
+
+	  @Test
+	  void shouldExecuteApplicationWithoutException() {
+	    assertDoesNotThrow(() -> App.main(new String[]{}));
+	  }
+}

acyclic-visitor/README.md

@@ -4,6 +4,7 @@ title: Acyclic Visitor
 folder: acyclic-visitor
 permalink: /patterns/acyclic-visitor/
 categories: Behavioral
+language: en
 tags:
  - Extensibility
 ---

acyclic-visitor/pom.xml

@@ -30,7 +30,7 @@
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-		<version>1.24.0-SNAPSHOT</version>
+		<version>1.25.0-SNAPSHOT</version>
 	</parent>
 
 	<artifactId>acyclic-visitor</artifactId>

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitor.java

@@ -23,17 +23,15 @@
 
 package com.iluwatar.acyclicvisitor;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * ConfigureForDosVisitor class implements both zoom's and  hayes' visit method for Dos
  * manufacturer.
  */
+@Slf4j
 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.");

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitor.java

@@ -23,17 +23,15 @@
 
 package com.iluwatar.acyclicvisitor;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * ConfigureForUnixVisitor class implements zoom's visit method for Unix manufacturer, unlike
  * traditional visitor pattern, this class may selectively implement visit for other modems.
  */
+@Slf4j
 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.");

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Hayes.java

@@ -23,16 +23,14 @@
 
 package com.iluwatar.acyclicvisitor;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * Hayes class implements its accept method.
  */
+@Slf4j
 public class Hayes extends Modem {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(ConfigureForDosVisitor.class);
-
   /**
    * Accepts all visitors but honors only HayesVisitor.
    */

acyclic-visitor/src/main/java/com/iluwatar/acyclicvisitor/Zoom.java

@@ -23,16 +23,14 @@
 
 package com.iluwatar.acyclicvisitor;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * Zoom class implements its accept method.
  */
+@Slf4j
 public class Zoom extends Modem {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(ConfigureForDosVisitor.class);
-
   /**
    * Accepts all visitors but honors only ZoomVisitor.
    */

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForDosVisitorTest.java

@@ -35,34 +35,34 @@ import uk.org.lidalia.slf4jtest.TestLoggerFactory;
 /**
  * ConfigureForDosVisitor test class
  */
-public class ConfigureForDosVisitorTest {
+class ConfigureForDosVisitorTest {
 
   private final TestLogger logger = TestLoggerFactory.getTestLogger(ConfigureForDosVisitor.class);
-  
+
   @Test
-  public void testVisitForZoom() {    
+  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() {
+  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();

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ConfigureForUnixVisitorTest.java

@@ -23,35 +23,34 @@
 
 package com.iluwatar.acyclicvisitor;
 
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+import uk.org.lidalia.slf4jtest.TestLogger;
+import uk.org.lidalia.slf4jtest.TestLoggerFactory;
+
 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 {
-  
+class ConfigureForUnixVisitorTest {
+
   private static final TestLogger LOGGER = TestLoggerFactory.getTestLogger(ConfigureForUnixVisitor.class);
-  
+
   @AfterEach
   public void clearLoggers() {
     TestLoggerFactory.clear();
   }
-  
+
   @Test
-  public void testVisitForZoom() {
+  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."));

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/HayesTest.java

@@ -23,34 +23,32 @@
 
 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;
 
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.*;
+
 /**
  * Hayes test class
  */
-public class HayesTest {
+class HayesTest {
 
   @Test
-  public void testAcceptForDos() {  
+  void testAcceptForDos() {
     var hayes = new Hayes();
     var mockVisitor = mock(ConfigureForDosVisitor.class);
-    
+
     hayes.accept(mockVisitor);
-    verify((HayesVisitor)mockVisitor).visit(eq(hayes));
+    verify((HayesVisitor) mockVisitor).visit(eq(hayes));
   }
-  
+
   @Test
-  public void testAcceptForUnix() {    
+  void testAcceptForUnix() {
     var hayes = new Hayes();
     var mockVisitor = mock(ConfigureForUnixVisitor.class);
-    
+
     hayes.accept(mockVisitor);
-    
+
     verifyZeroInteractions(mockVisitor);
   }
 }

acyclic-visitor/src/test/java/com/iluwatar/acyclicvisitor/ZoomTest.java

@@ -24,32 +24,32 @@
 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;
 
+import static org.mockito.Matchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+
 /**
  * Zoom test class
  */
-public class ZoomTest {
-  
+class ZoomTest {
+
   @Test
-  public void testAcceptForDos() {  
+  void testAcceptForDos() {
     var zoom = new Zoom();
     var mockVisitor = mock(ConfigureForDosVisitor.class);
-    
+
     zoom.accept(mockVisitor);
-    verify((ZoomVisitor)mockVisitor).visit(eq(zoom));
+    verify((ZoomVisitor) mockVisitor).visit(eq(zoom));
   }
-  
+
   @Test
-  public void testAcceptForUnix() {
+  void testAcceptForUnix() {
     var zoom = new Zoom();
     var mockVisitor = mock(ConfigureForUnixVisitor.class);
-    
+
     zoom.accept(mockVisitor);
-    verify((ZoomVisitor)mockVisitor).visit(eq(zoom));
+    verify((ZoomVisitor) mockVisitor).visit(eq(zoom));
   }
 }

adapter/README.md

@@ -4,6 +4,7 @@ title: Adapter
 folder: adapter
 permalink: /patterns/adapter/
 categories: Structural
+language: en
 tags:
  - Gang of Four
 ---
@@ -42,8 +43,8 @@ public interface RowingBoat {
   void row();
 }
 
+@Slf4j
 public class FishingBoat {
-  private static final Logger LOGGER = LoggerFactory.getLogger(FishingBoat.class);
   public void sail() {
     LOGGER.info("The fishing boat is sailing");
   }
@@ -70,10 +71,9 @@ public class Captain {
 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
+@Slf4j
 public class FishingBoatAdapter implements RowingBoat {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(FishingBoatAdapter.class);
-
   private final FishingBoat boat;
 
   public FishingBoatAdapter() {
@@ -105,7 +105,7 @@ Use the Adapter pattern when
 * 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:
+## 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.
@@ -118,7 +118,7 @@ An object adapter
 *	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
+## Known uses
 
 * [java.util.Arrays#asList()](http://docs.oracle.com/javase/8/docs/api/java/util/Arrays.html#asList%28T...%29)
 * [java.util.Collections#list()](https://docs.oracle.com/javase/8/docs/api/java/util/Collections.html#list-java.util.Enumeration-)

adapter/pom.xml

@@ -31,7 +31,7 @@
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-		<version>1.24.0-SNAPSHOT</version>
+		<version>1.25.0-SNAPSHOT</version>
 	</parent>
 	<artifactId>adapter</artifactId>
 	<dependencies>

adapter/src/main/java/com/iluwatar/adapter/Captain.java

@@ -23,24 +23,20 @@
 
 package com.iluwatar.adapter;
 
+import lombok.AllArgsConstructor;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
 /**
  * The Captain uses {@link RowingBoat} to sail. <br> This is the client in the pattern.
  */
+@Setter
+@NoArgsConstructor
+@AllArgsConstructor
 public final class Captain {
 
   private RowingBoat rowingBoat;
 
-  public Captain() {
-  }
-
-  public Captain(final RowingBoat boat) {
-    this.rowingBoat = boat;
-  }
-
-  void setRowingBoat(final RowingBoat boat) {
-    this.rowingBoat = boat;
-  }
-
   void row() {
     rowingBoat.row();
   }

adapter/src/main/java/com/iluwatar/adapter/FishingBoat.java

@@ -23,18 +23,15 @@
 
 package com.iluwatar.adapter;
 
-import static org.slf4j.LoggerFactory.getLogger;
-
-import org.slf4j.Logger;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * Device class (adaptee in the pattern). We want to reuse this class. Fishing boat moves by
  * sailing.
  */
+@Slf4j
 final class FishingBoat {
 
-  private static final Logger LOGGER = getLogger(FishingBoat.class);
-
   void sail() {
     LOGGER.info("The fishing boat is sailing");
   }

adapter/src/main/java/com/iluwatar/adapter/FishingBoatAdapter.java

@@ -29,11 +29,7 @@ package com.iluwatar.adapter;
  */
 public class FishingBoatAdapter implements RowingBoat {
 
-  private final FishingBoat boat;
-
-  public FishingBoatAdapter() {
-    boat = new FishingBoat();
-  }
+  private final FishingBoat boat = new FishingBoat();
 
   public final void row() {
     boat.sail();

adapter/src/test/java/com/iluwatar/adapter/AdapterPatternTest.java

@@ -23,18 +23,19 @@
 
 package com.iluwatar.adapter;
 
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.verify;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
 
 import java.util.HashMap;
 import java.util.Map;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
+
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.verify;
 
 /**
  * Test class
  */
-public class AdapterPatternTest {
+class AdapterPatternTest {
 
   private Map<String, Object> beans;
 
@@ -64,7 +65,7 @@ public class AdapterPatternTest {
    * by the client ({@link Captain} ).
    */
   @Test
-  public void testAdapter() {
+  void testAdapter() {
     var captain = (Captain) beans.get(ROWING_BEAN);
 
     // when captain moves

aggregator-microservices/README.md

@@ -4,6 +4,7 @@ title: Aggregator Microservices
 folder: aggregator-microservices
 permalink: /patterns/aggregator-microservices/
 categories: Architectural
+language: en
 tags:
 - Cloud distributed
 - Decoupling

aggregator-microservices/aggregator-service/pom.xml

@@ -29,7 +29,7 @@
 	<parent>
 		<artifactId>aggregator-microservices</artifactId>
 		<groupId>com.iluwatar</groupId>
-		<version>1.24.0-SNAPSHOT</version>
+		<version>1.25.0-SNAPSHOT</version>
 	</parent>
 	<modelVersion>4.0.0</modelVersion>
 	<artifactId>aggregator-service</artifactId>

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Aggregator.java

@@ -26,8 +26,7 @@ package com.iluwatar.aggregator.microservices;
 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.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 /**
@@ -37,20 +36,18 @@ import org.springframework.web.bind.annotation.RestController;
 @RestController
 public class Aggregator {
 
-
   @Resource
   private ProductInformationClient informationClient;
 
   @Resource
   private ProductInventoryClient inventoryClient;
 
-
   /**
    * Retrieves product data.
    *
    * @return a Product.
    */
-  @RequestMapping(path = "/product", method = RequestMethod.GET)
+  @GetMapping("/product")
   public Product getProduct() {
 
     var product = new Product();

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/Product.java

@@ -23,9 +23,14 @@
 
 package com.iluwatar.aggregator.microservices;
 
+import lombok.Getter;
+import lombok.Setter;
+
 /**
  * Encapsulates all the data for a Product that clients will request.
  */
+@Getter
+@Setter
 public class Product {
 
   /**
@@ -39,20 +44,4 @@ public class Product {
    */
   private int productInventories;
 
-  public String getTitle() {
-    return title;
-  }
-
-  public void setTitle(String title) {
-    this.title = title;
-  }
-
-  public int getProductInventories() {
-    return productInventories;
-  }
-
-  public void setProductInventories(int productInventories) {
-    this.productInventories = productInventories;
-  }
-
 }

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInformationClientImpl.java

@@ -28,18 +28,16 @@ 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 lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Component;
 
 /**
  * An adapter to communicate with information micro-service.
  */
+@Slf4j
 @Component
 public class ProductInformationClientImpl implements ProductInformationClient {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(ProductInformationClientImpl.class);
-
   @Override
   public String getProductTitle() {
     var request = HttpRequest.newBuilder()
@@ -54,6 +52,7 @@ public class ProductInformationClientImpl implements ProductInformationClient {
       LOGGER.error("IOException Occurred", ioe);
     } catch (InterruptedException ie) {
       LOGGER.error("InterruptedException Occurred", ie);
+      Thread.currentThread().interrupt();
     }
     return null;
   }

aggregator-microservices/aggregator-service/src/main/java/com/iluwatar/aggregator/microservices/ProductInventoryClientImpl.java

@@ -28,18 +28,16 @@ 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 lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Component;
 
 /**
  * An adapter to communicate with inventory micro-service.
  */
+@Slf4j
 @Component
 public class ProductInventoryClientImpl implements ProductInventoryClient {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(ProductInventoryClientImpl.class);
-
   @Override
   public Integer getProductInventories() {
     var response = "";
@@ -56,6 +54,7 @@ public class ProductInventoryClientImpl implements ProductInventoryClient {
       LOGGER.error("IOException Occurred", ioe);
     } catch (InterruptedException ie) {
       LOGGER.error("InterruptedException Occurred", ie);
+      Thread.currentThread().interrupt();
     }
     if ("".equalsIgnoreCase(response)) {
       return null;

aggregator-microservices/aggregator-service/src/test/java/com/iluwatar/aggregator/microservices/AggregatorTest.java

@@ -23,19 +23,19 @@
 
 package com.iluwatar.aggregator.microservices;
 
-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.jupiter.api.Assertions.assertEquals;
+import static org.mockito.Mockito.when;
+
 /**
  * Test Aggregation of domain objects
  */
-public class AggregatorTest {
+class AggregatorTest {
 
   @InjectMocks
   private Aggregator aggregator;
@@ -48,14 +48,14 @@ public class AggregatorTest {
 
   @BeforeEach
   public void setup() {
-    MockitoAnnotations.initMocks(this);
+    MockitoAnnotations.openMocks(this);
   }
 
   /**
    * Tests getting the data for a desktop client
    */
   @Test
-  public void testGetProduct() {
+  void testGetProduct() {
     var title = "The Product Title.";
     var inventories = 5;
 

aggregator-microservices/information-microservice/pom.xml

@@ -29,7 +29,7 @@
 	<parent>
 		<artifactId>aggregator-microservices</artifactId>
 		<groupId>com.iluwatar</groupId>
-		<version>1.24.0-SNAPSHOT</version>
+		<version>1.25.0-SNAPSHOT</version>
 	</parent>
 	<modelVersion>4.0.0</modelVersion>
 

aggregator-microservices/information-microservice/src/main/java/com/iluwatar/information/microservice/InformationController.java

@@ -23,8 +23,7 @@
 
 package com.iluwatar.information.microservice;
 
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 /**
@@ -38,7 +37,7 @@ public class InformationController {
    *
    * @return product inventory.
    */
-  @RequestMapping(value = "/information", method = RequestMethod.GET)
+  @GetMapping("/information")
   public String getProductTitle() {
     return "The Product Title.";
   }

aggregator-microservices/information-microservice/src/test/java/com/iluwatar/information/microservice/InformationControllerTest.java

@@ -23,17 +23,17 @@
 
 package com.iluwatar.information.microservice;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 /**
  * Test for Information Rest Controller
  */
-public class InformationControllerTest {
+class InformationControllerTest {
 
   @Test
-  public void shouldGetProductTitle() {
+  void shouldGetProductTitle() {
     var infoController = new InformationController();
     var title = infoController.getProductTitle();
     assertEquals("The Product Title.", title);

aggregator-microservices/inventory-microservice/pom.xml

@@ -29,7 +29,7 @@
 	<parent>
 		<artifactId>aggregator-microservices</artifactId>
 		<groupId>com.iluwatar</groupId>
-		<version>1.24.0-SNAPSHOT</version>
+		<version>1.25.0-SNAPSHOT</version>
 	</parent>
 	<modelVersion>4.0.0</modelVersion>
 	<artifactId>inventory-microservice</artifactId>

aggregator-microservices/inventory-microservice/src/main/java/com/iluwatar/inventory/microservice/InventoryController.java

@@ -23,8 +23,7 @@
 
 package com.iluwatar.inventory.microservice;
 
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 /**
@@ -38,7 +37,7 @@ public class InventoryController {
    *
    * @return product inventory.
    */
-  @RequestMapping(value = "/inventories", method = RequestMethod.GET)
+  @GetMapping("/inventories")
   public int getProductInventories() {
     return 5;
   }

aggregator-microservices/inventory-microservice/src/test/java/com/iluwatar/inventory/microservice/InventoryControllerTest.java

@@ -23,16 +23,17 @@
 
 package com.iluwatar.inventory.microservice;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 /**
  * Test Inventory Rest Controller
  */
-public class InventoryControllerTest {
+class InventoryControllerTest {
+
   @Test
-  public void testGetProductInventories() {
+  void testGetProductInventories() {
     var inventoryController = new InventoryController();
     var numberOfInventories = inventoryController.getProductInventories();
     assertEquals(5, numberOfInventories);

aggregator-microservices/pom.xml

@@ -29,7 +29,7 @@
     <parent>
         <artifactId>java-design-patterns</artifactId>
         <groupId>com.iluwatar</groupId>
-        <version>1.24.0-SNAPSHOT</version>
+        <version>1.25.0-SNAPSHOT</version>
     </parent>
     <modelVersion>4.0.0</modelVersion>
     <artifactId>aggregator-microservices</artifactId>

ambassador/README.md

@@ -4,6 +4,7 @@ title: Ambassador
 folder: ambassador
 permalink: /patterns/ambassador/
 categories: Structural
+language: en
 tags:
   - Decoupling
   - Cloud distributed
@@ -48,9 +49,8 @@ interface RemoteServiceInterface {
 A remote services represented as a singleton.
 
 ```java
+@Slf4j
 public class RemoteService implements RemoteServiceInterface {
-
-    private static final Logger LOGGER = LoggerFactory.getLogger(RemoteService.class);
     private static RemoteService service = null;
 
     static synchronized RemoteService getRemoteService() {
@@ -80,9 +80,8 @@ public class RemoteService implements RemoteServiceInterface {
 A service ambassador adding additional features such as logging, latency checks
 
 ```java
+@Slf4j
 public class ServiceAmbassador implements RemoteServiceInterface {
-
-  private static final Logger LOGGER = LoggerFactory.getLogger(ServiceAmbassador.class);
   private static final int RETRIES = 3;
   private static final int DELAY_MS = 3000;
 
@@ -132,9 +131,8 @@ public class ServiceAmbassador implements RemoteServiceInterface {
 A client has a local service ambassador used to interact with the remote service:
 
 ```java
+@Slf4j
 public class Client {
-
-  private static final Logger LOGGER = LoggerFactory.getLogger(Client.class);
   private final ServiceAmbassador serviceAmbassador = new ServiceAmbassador();
 
   long useService(int value) {

ambassador/pom.xml

@@ -29,7 +29,7 @@
 	<parent>
 		<artifactId>java-design-patterns</artifactId>
 		<groupId>com.iluwatar</groupId>
-		<version>1.24.0-SNAPSHOT</version>
+		<version>1.25.0-SNAPSHOT</version>
 	</parent>
 	<modelVersion>4.0.0</modelVersion>
 	<artifactId>ambassador</artifactId>

ambassador/src/main/java/com/iluwatar/ambassador/Client.java

@@ -23,20 +23,19 @@
 
 package com.iluwatar.ambassador;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * A simple Client.
  */
+@Slf4j
 public class Client {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(Client.class);
   private final ServiceAmbassador serviceAmbassador = new ServiceAmbassador();
 
   long useService(int value) {
     var result = serviceAmbassador.doRemoteFunction(value);
-    LOGGER.info("Service result: " + result);
+    LOGGER.info("Service result: {}", result);
     return result;
   }
 }

ambassador/src/main/java/com/iluwatar/ambassador/RemoteService.java

@@ -26,15 +26,14 @@ package com.iluwatar.ambassador;
 import static java.lang.Thread.sleep;
 
 import com.iluwatar.ambassador.util.RandomProvider;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * A remote legacy application represented by a Singleton implementation.
  */
+@Slf4j
 public class RemoteService implements RemoteServiceInterface {
   private static final int THRESHOLD = 200;
-  private static final Logger LOGGER = LoggerFactory.getLogger(RemoteService.class);
   private static RemoteService service = null;
   private final RandomProvider randomProvider;
 
@@ -73,8 +72,9 @@ public class RemoteService implements RemoteServiceInterface {
       sleep(waitTime);
     } catch (InterruptedException e) {
       LOGGER.error("Thread sleep state interrupted", e);
+      Thread.currentThread().interrupt();
     }
     return waitTime <= THRESHOLD ? value * 10
-            : RemoteServiceStatus.FAILURE.getRemoteServiceStatusValue();
+        : RemoteServiceStatus.FAILURE.getRemoteServiceStatusValue();
   }
 }

ambassador/src/main/java/com/iluwatar/ambassador/RemoteServiceStatus.java

@@ -33,8 +33,7 @@ package com.iluwatar.ambassador;
  */
 
 public enum RemoteServiceStatus {
-  FAILURE(-1)
-  ;
+  FAILURE(-1);
 
   private final long remoteServiceStatusValue;
 

ambassador/src/main/java/com/iluwatar/ambassador/ServiceAmbassador.java

@@ -26,17 +26,16 @@ package com.iluwatar.ambassador;
 import static com.iluwatar.ambassador.RemoteServiceStatus.FAILURE;
 import static java.lang.Thread.sleep;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
  * ServiceAmbassador provides an interface for a ({@link Client}) to access ({@link RemoteService}).
  * The interface adds logging, latency testing and usage of the service in a safe way that will not
  * add stress to the remote service when connectivity issues occur.
  */
+@Slf4j
 public class ServiceAmbassador implements RemoteServiceInterface {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(ServiceAmbassador.class);
   private static final int RETRIES = 3;
   private static final int DELAY_MS = 3000;
 
@@ -53,7 +52,7 @@ public class ServiceAmbassador implements RemoteServiceInterface {
     var result = RemoteService.getRemoteService().doRemoteFunction(value);
     var timeTaken = System.currentTimeMillis() - startTime;
 
-    LOGGER.info("Time taken (ms): " + timeTaken);
+    LOGGER.info("Time taken (ms): {}", timeTaken);
     return result;
   }
 
@@ -67,12 +66,13 @@ public class ServiceAmbassador implements RemoteServiceInterface {
       }
 
       if ((result = checkLatency(value)) == FAILURE.getRemoteServiceStatusValue()) {
-        LOGGER.info("Failed to reach remote: (" + (i + 1) + ")");
+        LOGGER.info("Failed to reach remote: ({})", i + 1);
         retries++;
         try {
           sleep(DELAY_MS);
         } catch (InterruptedException e) {
           LOGGER.error("Thread sleep state interrupted", e);
+          Thread.currentThread().interrupt();
         }
       } else {
         break;

api-gateway/README.md

@@ -4,6 +4,7 @@ title: API Gateway
 folder: api-gateway
 permalink: /patterns/api-gateway/
 categories: Architectural
+language: en
 tags:
   - Cloud distributed
   - Decoupling

api-gateway/api-gateway-service/pom.xml

@@ -29,7 +29,7 @@
   <parent>
     <artifactId>api-gateway</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.24.0-SNAPSHOT</version>
+    <version>1.25.0-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <artifactId>api-gateway-service</artifactId>

api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ApiGateway.java

@@ -24,8 +24,7 @@
 package com.iluwatar.api.gateway;
 
 import javax.annotation.Resource;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 /**
@@ -45,7 +44,7 @@ public class ApiGateway {
    *
    * @return Product information for clients on a desktop
    */
-  @RequestMapping(path = "/desktop", method = RequestMethod.GET)
+  @GetMapping("/desktop")
   public DesktopProduct getProductDesktop() {
     var desktopProduct = new DesktopProduct();
     desktopProduct.setImagePath(imageClient.getImagePath());
@@ -58,7 +57,7 @@ public class ApiGateway {
    *
    * @return Product information for clients on a mobile device
    */
-  @RequestMapping(path = "/mobile", method = RequestMethod.GET)
+  @GetMapping("/mobile")
   public MobileProduct getProductMobile() {
     var mobileProduct = new MobileProduct();
     mobileProduct.setPrice(priceClient.getPrice());

api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/DesktopProduct.java

@@ -23,10 +23,16 @@
 
 package com.iluwatar.api.gateway;
 
+import lombok.Getter;
+import lombok.Setter;
+
 /**
  * Encapsulates all of the information that a desktop client needs to display a product.
  */
+@Getter
+@Setter
 public class DesktopProduct {
+
   /**
    * The price of the product.
    */
@@ -37,19 +43,4 @@ public class DesktopProduct {
    */
   private String imagePath;
 
-  public String getPrice() {
-    return price;
-  }
-
-  public void setPrice(String price) {
-    this.price = price;
-  }
-
-  public String getImagePath() {
-    return imagePath;
-  }
-
-  public void setImagePath(String imagePath) {
-    this.imagePath = imagePath;
-  }
 }

api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ImageClientImpl.java

@@ -23,24 +23,21 @@
 
 package com.iluwatar.api.gateway;
 
-import static org.slf4j.LoggerFactory.getLogger;
-
 import java.io.IOException;
 import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
 import java.net.http.HttpResponse.BodyHandlers;
-
-import org.slf4j.Logger;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Component;
 
 /**
  * An adapter to communicate with the Image microservice.
  */
+@Slf4j
 @Component
 public class ImageClientImpl implements ImageClient {
-  private static final Logger LOGGER = getLogger(ImageClientImpl.class);
 
   /**
    * Makes a simple HTTP Get request to the Image microservice.
@@ -60,8 +57,11 @@ public class ImageClientImpl implements ImageClient {
       var httpResponse = httpClient.send(httpGet, BodyHandlers.ofString());
       logResponse(httpResponse);
       return httpResponse.body();
-    } catch (IOException | InterruptedException e) {
-      LOGGER.error("Failure occurred while getting image path", e);
+    } catch (IOException ioe) {
+      LOGGER.error("Failure occurred while getting image path", ioe);
+    } catch (InterruptedException ie) {
+      LOGGER.error("Failure occurred while getting image path", ie);
+      Thread.currentThread().interrupt();
     }
 
     return null;

api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/MobileProduct.java

@@ -23,20 +23,17 @@
 
 package com.iluwatar.api.gateway;
 
+import lombok.Getter;
+import lombok.Setter;
+
 /**
  * Encapsulates all of the information that mobile client needs to display a product.
  */
+@Getter
+@Setter
 public class MobileProduct {
   /**
    * The price of the product.
    */
   private String price;
-
-  public String getPrice() {
-    return price;
-  }
-
-  public void setPrice(String price) {
-    this.price = price;
-  }
 }

api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/PriceClientImpl.java

@@ -23,25 +23,22 @@
 
 package com.iluwatar.api.gateway;
 
-import static org.slf4j.LoggerFactory.getLogger;
-
 import java.io.IOException;
 import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
 import java.net.http.HttpResponse.BodyHandlers;
-
-import org.slf4j.Logger;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.stereotype.Component;
 
 
 /**
  * An adapter to communicate with the Price microservice.
  */
+@Slf4j
 @Component
 public class PriceClientImpl implements PriceClient {
-  private static final Logger LOGGER = getLogger(PriceClientImpl.class);
 
   /**
    * Makes a simple HTTP Get request to the Price microservice.
@@ -61,8 +58,11 @@ public class PriceClientImpl implements PriceClient {
       var httpResponse = httpClient.send(httpGet, BodyHandlers.ofString());
       logResponse(httpResponse);
       return httpResponse.body();
-    } catch (IOException | InterruptedException e) {
+    } catch (IOException e) {
       LOGGER.error("Failure occurred while getting price info", e);
+    } catch (InterruptedException e) {
+      LOGGER.error("Failure occurred while getting price info", e);
+      Thread.currentThread().interrupt();
     }
 
     return null;

api-gateway/api-gateway-service/src/test/java/com/iluwatar/api/gateway/ApiGatewayTest.java

@@ -35,7 +35,7 @@ import org.mockito.MockitoAnnotations;
 /**
  * Test API Gateway Pattern
  */
-public class ApiGatewayTest {
+class ApiGatewayTest {
 
   @InjectMocks
   private ApiGateway apiGateway;
@@ -48,14 +48,14 @@ public class ApiGatewayTest {
 
   @BeforeEach
   public void setup() {
-    MockitoAnnotations.initMocks(this);
+    MockitoAnnotations.openMocks(this);
   }
 
   /**
    * Tests getting the data for a desktop client
    */
   @Test
-  public void testGetProductDesktop() {
+  void testGetProductDesktop() {
     var imagePath = "/product-image.png";
     var price = "20";
     when(imageClient.getImagePath()).thenReturn(imagePath);
@@ -71,7 +71,7 @@ public class ApiGatewayTest {
    * Tests getting the data for a mobile client
    */
   @Test
-  public void testGetProductMobile() {
+  void testGetProductMobile() {
     var price = "20";
     when(priceClient.getPrice()).thenReturn(price);
 

api-gateway/image-microservice/pom.xml

@@ -29,7 +29,7 @@
   <parent>
     <artifactId>api-gateway</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.24.0-SNAPSHOT</version>
+    <version>1.25.0-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <artifactId>image-microservice</artifactId>

api-gateway/image-microservice/src/main/java/com/iluwatar/image/microservice/ImageController.java

@@ -23,27 +23,24 @@
 
 package com.iluwatar.image.microservice;
 
-import static org.slf4j.LoggerFactory.getLogger;
-
-import org.slf4j.Logger;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 
 /**
  * Exposes the Image microservice's endpoints.
  */
+@Slf4j
 @RestController
 public class ImageController {
-  private static final Logger LOGGER = getLogger(ImageController.class);
 
   /**
    * An endpoint for a user to retrieve an image path.
    *
    * @return An image path
    */
-  @RequestMapping(value = "/image-path", method = RequestMethod.GET)
+  @GetMapping("/image-path")
   public String getImagePath() {
     LOGGER.info("Successfully found image path");
     return "/product-image.png";

api-gateway/image-microservice/src/test/java/com/iluwatar/image/microservice/ImageControllerTest.java

@@ -23,16 +23,17 @@
 
 package com.iluwatar.image.microservice;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 /**
  * Test for Image Rest Controller
  */
-public class ImageControllerTest {
+class ImageControllerTest {
+
   @Test
-  public void testGetImagePath() {
+  void testGetImagePath() {
     var imageController = new ImageController();
     var imagePath = imageController.getImagePath();
     assertEquals("/product-image.png", imagePath);

api-gateway/pom.xml

@@ -29,7 +29,7 @@
   <parent>
     <artifactId>java-design-patterns</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.24.0-SNAPSHOT</version>
+    <version>1.25.0-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
   <artifactId>api-gateway</artifactId>

api-gateway/price-microservice/pom.xml

@@ -29,7 +29,7 @@
   <parent>
     <artifactId>api-gateway</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.24.0-SNAPSHOT</version>
+    <version>1.25.0-SNAPSHOT</version>
   </parent>
 
   <modelVersion>4.0.0</modelVersion>

api-gateway/price-microservice/src/main/java/com/iluwatar/price/microservice/PriceController.java

@@ -23,27 +23,24 @@
 
 package com.iluwatar.price.microservice;
 
-import static org.slf4j.LoggerFactory.getLogger;
-
-import org.slf4j.Logger;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RequestMethod;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
 
 
 /**
  * Exposes the Price microservice's endpoints.
  */
+@Slf4j
 @RestController
 public class PriceController {
-  private static final Logger LOGGER = getLogger(PriceController.class);
 
   /**
    * An endpoint for a user to retrieve a product's price.
    *
    * @return A product's price
    */
-  @RequestMapping(value = "/price", method = RequestMethod.GET)
+  @GetMapping("/price")
   public String getPrice() {
     LOGGER.info("Successfully found price info");
     return "20";

api-gateway/price-microservice/src/test/java/com/iluwatar/price/microservice/PriceControllerTest.java

@@ -23,16 +23,17 @@
 
 package com.iluwatar.price.microservice;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 /**
  * Test for Price Rest Controller
  */
-public class PriceControllerTest {
+class PriceControllerTest {
+
   @Test
-  public void testgetPrice() {
+  void testgetPrice() {
     var priceController = new PriceController();
     var price = priceController.getPrice();
     assertEquals("20", price);

arrange-act-assert/README.md

@@ -4,6 +4,7 @@ title: Arrange/Act/Assert
 folder: arrange-act-assert
 permalink: /patterns/arrange-act-assert/
 categories: Idiom
+language: en
 tags:
  - Testing
 ---
@@ -81,10 +82,10 @@ Then we write our unit tests according to Arrange/Act/Assert pattern. Notice the
 separated steps for each unit test.
 
 ```java
-public class CashAAATest {
+class CashAAATest {
 
   @Test
-  public void testPlus() {
+  void testPlus() {
     //Arrange
     var cash = new Cash(3);
     //Act
@@ -94,7 +95,7 @@ public class CashAAATest {
   }
 
   @Test
-  public void testMinus() {
+  void testMinus() {
     //Arrange
     var cash = new Cash(8);
     //Act
@@ -105,7 +106,7 @@ public class CashAAATest {
   }
 
   @Test
-  public void testInsufficientMinus() {
+  void testInsufficientMinus() {
     //Arrange
     var cash = new Cash(1);
     //Act
@@ -116,7 +117,7 @@ public class CashAAATest {
   }
 
   @Test
-  public void testUpdate() {
+  void testUpdate() {
     //Arrange
     var cash = new Cash(5);
     //Act

arrange-act-assert/pom.xml

@@ -29,15 +29,15 @@
   <parent>
     <artifactId>java-design-patterns</artifactId>
     <groupId>com.iluwatar</groupId>
-    <version>1.24.0-SNAPSHOT</version>
+    <version>1.25.0-SNAPSHOT</version>
   </parent>
   <modelVersion>4.0.0</modelVersion>
 
   <artifactId>arrange-act-assert</artifactId>
   <dependencies>
     <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
+      <groupId>org.junit.jupiter</groupId>
+      <artifactId>junit-jupiter-engine</artifactId>
       <scope>test</scope>
     </dependency>
   </dependencies>

arrange-act-assert/src/main/java/com/iluwatar/arrangeactassert/Cash.java

@@ -23,18 +23,17 @@
 
 package com.iluwatar.arrangeactassert;
 
+import lombok.AllArgsConstructor;
+
 /**
  * Arrange/Act/Assert (AAA) is a unit test pattern. In this simple example, we have a ({@link Cash})
  * object for plus, minus and counting amount.
  */
+@AllArgsConstructor
 public class Cash {
 
   private int amount;
 
-  Cash(int amount) {
-    this.amount = amount;
-  }
-
   //plus
   void plus(int addend) {
     amount += addend;

arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAAATest.java

@@ -23,11 +23,11 @@
 
 package com.iluwatar.arrangeactassert;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 /**
  * Arrange/Act/Assert (AAA) is a pattern for organizing unit tests. It is a way to structure your
@@ -51,10 +51,11 @@ import org.junit.Test;
  * change and one reason to fail. In a large and complicated code base, tests that honor the single
  * responsibility principle are much easier to troubleshoot.
  */
-public class CashAAATest {
+
+class CashAAATest {
 
   @Test
-  public void testPlus() {
+  void testPlus() {
     //Arrange
     var cash = new Cash(3);
     //Act
@@ -64,7 +65,7 @@ public class CashAAATest {
   }
 
   @Test
-  public void testMinus() {
+  void testMinus() {
     //Arrange
     var cash = new Cash(8);
     //Act
@@ -75,7 +76,7 @@ public class CashAAATest {
   }
 
   @Test
-  public void testInsufficientMinus() {
+  void testInsufficientMinus() {
     //Arrange
     var cash = new Cash(1);
     //Act
@@ -86,7 +87,7 @@ public class CashAAATest {
   }
 
   @Test
-  public void testUpdate() {
+  void testUpdate() {
     //Arrange
     var cash = new Cash(5);
     //Act

arrange-act-assert/src/test/java/com/iluwatar/arrangeactassert/CashAntiAAATest.java

@@ -23,23 +23,24 @@
 
 package com.iluwatar.arrangeactassert;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 /**
  * ({@link CashAAATest}) is an anti-example of AAA pattern. This test is functionally correct, but
- * with the addition of new feature, it needs refactoring. There are an awful lot of steps in that
+ * with the addition of a new feature, it needs refactoring. There are an awful lot of steps in that
  * test method, but it verifies the class' important behavior in just eleven lines. It violates the
  * single responsibility principle. If this test method failed after a small code change, it might
  * take some digging to discover why.
  */
-public class CashAntiAAATest {
+
+class CashAntiAAATest {
 
   @Test
-  public void testCash() {
+  void testCash() {
     //initialize
     var cash = new Cash(3);
     //test plus

async-method-invocation/README.md

@@ -4,26 +4,166 @@ title: Async Method Invocation
 folder: async-method-invocation
 permalink: /patterns/async-method-invocation/
 categories: Concurrency
+language: en
 tags:
  - Reactive
 ---
 
 ## Intent
-Asynchronous method invocation is pattern where the calling thread
+
+Asynchronous method invocation is a pattern where the calling thread
 is not blocked while waiting results of tasks. The pattern provides parallel
 processing of multiple independent tasks and retrieving the results via
 callbacks or waiting until everything is done. 
 
+## Explanation
+
+Real world example
+
+> Launching space rockets is an exciting business. The mission command gives an order to launch and 
+> after some undetermined time, the rocket either launches successfully or fails miserably.
+
+In plain words
+
+> Asynchronous method invocation starts task processing and returns immediately before the task is 
+> ready. The results of the task processing are returned to the caller later.
+
+Wikipedia says
+
+> In multithreaded computer programming, asynchronous method invocation (AMI), also known as 
+> asynchronous method calls or the asynchronous pattern is a design pattern in which the call site 
+> is not blocked while waiting for the called code to finish. Instead, the calling thread is 
+> notified when the reply arrives. Polling for a reply is an undesired option.
+
+**Programmatic Example**
+
+In this example, we are launching space rockets and deploying lunar rovers.
+
+The application demonstrates the async method invocation pattern. The key parts of the pattern are 
+`AsyncResult` which is an intermediate container for an asynchronously evaluated value, 
+`AsyncCallback` which can be provided to be executed on task completion and `AsyncExecutor` that 
+manages the execution of the async tasks.
+
+```java
+public interface AsyncResult<T> {
+  boolean isCompleted();
+  T getValue() throws ExecutionException;
+  void await() throws InterruptedException;
+}
+```
+
+```java
+public interface AsyncCallback<T> {
+  void onComplete(T value, Optional<Exception> ex);
+}
+```
+
+```java
+public interface AsyncExecutor {
+  <T> AsyncResult<T> startProcess(Callable<T> task);
+  <T> AsyncResult<T> startProcess(Callable<T> task, AsyncCallback<T> callback);
+  <T> T endProcess(AsyncResult<T> asyncResult) throws ExecutionException, InterruptedException;
+}
+```
+
+`ThreadAsyncExecutor` is an implementation of `AsyncExecutor`. Some of its key parts are highlighted 
+next.
+
+```java
+public class ThreadAsyncExecutor implements AsyncExecutor {
+
+  @Override
+  public <T> AsyncResult<T> startProcess(Callable<T> task) {
+    return startProcess(task, null);
+  }
+
+  @Override
+  public <T> AsyncResult<T> startProcess(Callable<T> task, AsyncCallback<T> callback) {
+    var result = new CompletableResult<>(callback);
+    new Thread(
+            () -> {
+              try {
+                result.setValue(task.call());
+              } catch (Exception ex) {
+                result.setException(ex);
+              }
+            },
+            "executor-" + idx.incrementAndGet())
+        .start();
+    return result;
+  }
+
+  @Override
+  public <T> T endProcess(AsyncResult<T> asyncResult)
+      throws ExecutionException, InterruptedException {
+    if (!asyncResult.isCompleted()) {
+      asyncResult.await();
+    }
+    return asyncResult.getValue();
+  }
+}
+```
+
+Then we are ready to launch some rockets to see how everything works together.
+
+```java
+public static void main(String[] args) throws Exception {
+  // construct a new executor that will run async tasks
+  var executor = new ThreadAsyncExecutor();
+
+  // start few async tasks with varying processing times, two last with callback handlers
+  final var asyncResult1 = executor.startProcess(lazyval(10, 500));
+  final var asyncResult2 = executor.startProcess(lazyval("test", 300));
+  final var asyncResult3 = executor.startProcess(lazyval(50L, 700));
+  final var asyncResult4 = executor.startProcess(lazyval(20, 400), callback("Deploying lunar rover"));
+  final var asyncResult5 =
+      executor.startProcess(lazyval("callback", 600), callback("Deploying lunar rover"));
+
+  // emulate processing in the current thread while async tasks are running in their own threads
+  Thread.sleep(350); // Oh boy, we are working hard here
+  log("Mission command is sipping coffee");
+
+  // wait for completion of the tasks
+  final var result1 = executor.endProcess(asyncResult1);
+  final var result2 = executor.endProcess(asyncResult2);
+  final var result3 = executor.endProcess(asyncResult3);
+  asyncResult4.await();
+  asyncResult5.await();
+
+  // log the results of the tasks, callbacks log immediately when complete
+  log("Space rocket <" + result1 + "> launch complete");
+  log("Space rocket <" + result2 + "> launch complete");
+  log("Space rocket <" + result3 + "> launch complete");
+}
+```
+
+Here's the program console output.
+
+```java
+21:47:08.227 [executor-2] INFO com.iluwatar.async.method.invocation.App - Space rocket <test> launched successfully
+21:47:08.269 [main] INFO com.iluwatar.async.method.invocation.App - Mission command is sipping coffee
+21:47:08.318 [executor-4] INFO com.iluwatar.async.method.invocation.App - Space rocket <20> launched successfully
+21:47:08.335 [executor-4] INFO com.iluwatar.async.method.invocation.App - Deploying lunar rover <20>
+21:47:08.414 [executor-1] INFO com.iluwatar.async.method.invocation.App - Space rocket <10> launched successfully
+21:47:08.519 [executor-5] INFO com.iluwatar.async.method.invocation.App - Space rocket <callback> launched successfully
+21:47:08.519 [executor-5] INFO com.iluwatar.async.method.invocation.App - Deploying lunar rover <callback>
+21:47:08.616 [executor-3] INFO com.iluwatar.async.method.invocation.App - Space rocket <50> launched successfully
+21:47:08.617 [main] INFO com.iluwatar.async.method.invocation.App - Space rocket <10> launch complete
+21:47:08.617 [main] INFO com.iluwatar.async.method.invocation.App - Space rocket <test> launch complete
+21:47:08.618 [main] INFO com.iluwatar.async.method.invocation.App - Space rocket <50> launch complete
+```
+
 # Class diagram
+
 ![alt text](./etc/async-method-invocation.png "Async Method Invocation")
 
 ## Applicability
-Use async method invocation pattern when
+
+Use the async method invocation pattern when
 
 * You have multiple independent tasks that can run in parallel
 * You need to improve the performance of a group of sequential tasks
-* You have limited amount of processing capacity or long running tasks and the
-  caller should not wait the tasks to be ready
+* You have a limited amount of processing capacity or long-running tasks and the caller should not wait for the tasks to be ready
 
 ## Real world examples
 

async-method-invocation/pom.xml

@@ -31,7 +31,7 @@
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-		<version>1.24.0-SNAPSHOT</version>
+		<version>1.25.0-SNAPSHOT</version>
 	</parent>
 	<artifactId>async-method-invocation</artifactId>
 	<dependencies>
@@ -45,11 +45,6 @@
 			<artifactId>mockito-core</artifactId>
 			<scope>test</scope>
 		</dependency>
-		<dependency>
-			<groupId>junit</groupId>
-			<artifactId>junit</artifactId>
-			<scope>test</scope>
-		</dependency>
 	</dependencies>
 	<build>
 		<plugins>

async-method-invocation/src/main/java/com/iluwatar/async/method/invocation/App.java

@@ -24,14 +24,15 @@
 package com.iluwatar.async.method.invocation;
 
 import java.util.concurrent.Callable;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
+import lombok.extern.slf4j.Slf4j;
 
 /**
- * This application demonstrates the async method invocation pattern. Key parts of the pattern are
- * <code>AsyncResult</code> which is an intermediate container for an asynchronously evaluated
- * value, <code>AsyncCallback</code> which can be provided to be executed on task completion and
- * <code>AsyncExecutor</code> that manages the execution of the async tasks.
+ * In this example, we are launching space rockets and deploying lunar rovers.
+ *
+ * <p>The application demonstrates the async method invocation pattern. The key parts of the
+ * pattern are <code>AsyncResult</code> which is an intermediate container for an asynchronously
+ * evaluated value, <code>AsyncCallback</code> which can be provided to be executed on task
+ * completion and <code>AsyncExecutor</code> that manages the execution of the async tasks.
  *
  * <p>The main method shows example flow of async invocations. The main thread starts multiple
  * tasks with variable durations and then continues its own work. When the main thread has done it's
@@ -55,13 +56,15 @@ import org.slf4j.LoggerFactory;
  * @see java.util.concurrent.CompletableFuture
  * @see java.util.concurrent.ExecutorService
  */
+@Slf4j
 public class App {
 
-  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
+  private static final String ROCKET_LAUNCH_LOG_PATTERN = "Space rocket <%s> launched successfully";
 
   /**
    * Program entry point.
    */
+
   public static void main(String[] args) throws Exception {
     // construct a new executor that will run async tasks
     var executor = new ThreadAsyncExecutor();
@@ -70,13 +73,14 @@ public class App {
     final var asyncResult1 = executor.startProcess(lazyval(10, 500));
     final var asyncResult2 = executor.startProcess(lazyval("test", 300));
     final var asyncResult3 = executor.startProcess(lazyval(50L, 700));
-    final var asyncResult4 = executor.startProcess(lazyval(20, 400), callback("Callback result 4"));
+    final var asyncResult4 = executor.startProcess(lazyval(20, 400),
+        callback("Deploying lunar rover"));
     final var asyncResult5 =
-        executor.startProcess(lazyval("callback", 600), callback("Callback result 5"));
+        executor.startProcess(lazyval("callback", 600), callback("Deploying lunar rover"));
 
     // emulate processing in the current thread while async tasks are running in their own threads
-    Thread.sleep(350); // Oh boy I'm working hard here
-    log("Some hard work done");
+    Thread.sleep(350); // Oh boy, we are working hard here
+    log("Mission command is sipping coffee");
 
     // wait for completion of the tasks
     final var result1 = executor.endProcess(asyncResult1);
@@ -86,9 +90,9 @@ public class App {
     asyncResult5.await();
 
     // log the results of the tasks, callbacks log immediately when complete
-    log("Result 1: " + result1);
-    log("Result 2: " + result2);
-    log("Result 3: " + result3);
+    log(String.format(ROCKET_LAUNCH_LOG_PATTERN, result1));
+    log(String.format(ROCKET_LAUNCH_LOG_PATTERN, result2));
+    log(String.format(ROCKET_LAUNCH_LOG_PATTERN, result3));
   }
 
   /**
@@ -101,7 +105,7 @@ public class App {
   private static <T> Callable<T> lazyval(T value, long delayMillis) {
     return () -> {
       Thread.sleep(delayMillis);
-      log("Task completed with: " + value);
+      log(String.format(ROCKET_LAUNCH_LOG_PATTERN, value));
       return value;
     };
   }
@@ -117,7 +121,7 @@ public class App {
       if (ex.isPresent()) {
         log(name + " failed: " + ex.map(Exception::getMessage).orElse(""));
       } else {
-        log(name + ": " + value);
+        log(name + " <" + value + ">");
       }
     };
   }

async-method-invocation/src/test/java/com/iluwatar/async/method/invocation/ThreadAsyncExecutorTest.java

@@ -68,7 +68,7 @@ class ThreadAsyncExecutorTest {
 
   @BeforeEach
   void setUp() {
-    MockitoAnnotations.initMocks(this);
+    MockitoAnnotations.openMocks(this);
   }
 
   /**

balking/README.md

@@ -4,24 +4,137 @@ title: Balking
 folder: balking
 permalink: /patterns/balking/
 categories: Concurrency
+language: en
 tags:
  - Decoupling
 ---
 
 ## Intent
-Balking Pattern is used to prevent an object from executing certain code if it is an
-incomplete or inappropriate state
+
+Balking Pattern is used to prevent an object from executing a certain code if it is in an incomplete 
+or inappropriate state.
+
+## Explanation
+
+Real world example
+
+> There's a start-button in a washing machine to initiate the laundry washing. When the washing 
+> machine is inactive the button works as expected, but if it's already washing the button does
+> nothing.
+
+In plain words
+
+> Using the balking pattern, a certain code executes only if the object is in particular state.
+
+Wikipedia says
+
+> The balking pattern is a software design pattern that only executes an action on an object when 
+> the object is in a particular state. For example, if an object reads ZIP files and a calling 
+> method invokes a get method on the object when the ZIP file is not open, the object would "balk" 
+> at the request.
+
+**Programmatic Example**
+
+In this example implementation, `WashingMachine` is an object that has two states in which it can 
+be: ENABLED and WASHING. If the machine is ENABLED, the state changes to WASHING using a thread-safe
+method. On the other hand, if it already has been washing and any other thread executes `wash()` 
+it won't do that and returns without doing anything.
+
+Here are the relevant parts of the `WashingMachine` class.
+
+```java
+@Slf4j
+public class WashingMachine {
+
+  private final DelayProvider delayProvider;
+  private WashingMachineState washingMachineState;
+
+  public WashingMachine(DelayProvider delayProvider) {
+    this.delayProvider = delayProvider;
+    this.washingMachineState = WashingMachineState.ENABLED;
+  }
+
+  public WashingMachineState getWashingMachineState() {
+    return washingMachineState;
+  }
+
+  public void wash() {
+    synchronized (this) {
+      var machineState = getWashingMachineState();
+      LOGGER.info("{}: Actual machine state: {}", Thread.currentThread().getName(), machineState);
+      if (this.washingMachineState == WashingMachineState.WASHING) {
+        LOGGER.error("Cannot wash if the machine has been already washing!");
+        return;
+      }
+      this.washingMachineState = WashingMachineState.WASHING;
+    }
+    LOGGER.info("{}: Doing the washing", Thread.currentThread().getName());
+    this.delayProvider.executeAfterDelay(50, TimeUnit.MILLISECONDS, this::endOfWashing);
+  }
+
+  public synchronized void endOfWashing() {
+    washingMachineState = WashingMachineState.ENABLED;
+    LOGGER.info("{}: Washing completed.", Thread.currentThread().getId());
+  }
+}
+```
+
+Here's the simple `DelayProvider` interface used by the `WashingMachine`.
+
+```java
+public interface DelayProvider {
+  void executeAfterDelay(long interval, TimeUnit timeUnit, Runnable task);
+}
+```
+
+Now we introduce the application using the `WashingMachine`.
+
+```java
+  public static void main(String... args) {
+    final var washingMachine = new WashingMachine();
+    var executorService = Executors.newFixedThreadPool(3);
+    for (int i = 0; i < 3; i++) {
+      executorService.execute(washingMachine::wash);
+    }
+    executorService.shutdown();
+    try {
+      executorService.awaitTermination(10, TimeUnit.SECONDS);
+    } catch (InterruptedException ie) {
+      LOGGER.error("ERROR: Waiting on executor service shutdown!");
+      Thread.currentThread().interrupt();
+    }
+  }
+```
+
+Here is the console output of the program.
+
+```
+14:02:52.268 [pool-1-thread-2] INFO com.iluwatar.balking.WashingMachine - pool-1-thread-2: Actual machine state: ENABLED
+14:02:52.272 [pool-1-thread-2] INFO com.iluwatar.balking.WashingMachine - pool-1-thread-2: Doing the washing
+14:02:52.272 [pool-1-thread-3] INFO com.iluwatar.balking.WashingMachine - pool-1-thread-3: Actual machine state: WASHING
+14:02:52.273 [pool-1-thread-3] ERROR com.iluwatar.balking.WashingMachine - Cannot wash if the machine has been already washing!
+14:02:52.273 [pool-1-thread-1] INFO com.iluwatar.balking.WashingMachine - pool-1-thread-1: Actual machine state: WASHING
+14:02:52.273 [pool-1-thread-1] ERROR com.iluwatar.balking.WashingMachine - Cannot wash if the machine has been already washing!
+14:02:52.324 [pool-1-thread-2] INFO com.iluwatar.balking.WashingMachine - 14: Washing completed.
+```
 
 ## Class diagram
+
 ![alt text](./etc/balking.png "Balking")
 
 ## Applicability
+
 Use the Balking pattern when
 
-* you want to invoke an action on an object only when it is in a particular state
-* objects are generally only in a state that is prone to balking temporarily
-but for an unknown amount of time
+* You want to invoke an action on an object only when it is in a particular state
+* Objects are generally only in a state that is prone to balking temporarily but for an unknown 
+  amount of time
 
 ## Related patterns
-* Guarded Suspension Pattern
-* Double Checked Locking Pattern
+
+* [Guarded Suspension Pattern](https://java-design-patterns.com/patterns/guarded-suspension/)
+* [Double Checked Locking Pattern](https://java-design-patterns.com/patterns/double-checked-locking/)
+
+## Credits
+
+* [Patterns in Java: A Catalog of Reusable Design Patterns Illustrated with UML, 2nd Edition, Volume 1](https://www.amazon.com/gp/product/0471227293/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=javadesignpat-20&creative=9325&linkCode=as2&creativeASIN=0471227293&linkId=0e39a59ffaab93fb476036fecb637b99)

balking/pom.xml

@@ -29,7 +29,7 @@
 	<parent>
 		<artifactId>java-design-patterns</artifactId>
 		<groupId>com.iluwatar</groupId>
-		<version>1.24.0-SNAPSHOT</version>
+		<version>1.25.0-SNAPSHOT</version>
 	</parent>
 	<modelVersion>4.0.0</modelVersion>