Reach milestone 1.17.0

Removed redundant times(1) params for verify()

.gitignore

@@ -1,14 +1,20 @@
-target
-.metadata
-.settings
-.classpath
-.project
-*.class
-# Package Files #
-*.jar
-*.war
-*.ear
-.idea
-*.iml
-*.swp
-datanucleus.log
+target
+.metadata
+.settings
+.classpath
+.project
+*.class
+# Package Files #
+*.jar
+*.war
+*.ear
+.idea
+*.iml
+*.swp
+datanucleus.log
+/bin/
+/bin/
+/bin/
+*.log
+data-mapper/src/main/resources/log4j.xml
+event-sourcing/Journal.json

.travis.yml

@@ -6,13 +6,34 @@ env:
   global:
   - GH_REF: github.com/iluwatar/java-design-patterns.git
   - secure: LxTDuNS/rBWIvKkaEqr79ImZAe48mCdoYCF41coxNXgNoippo4GIBArknqtv+XvdkiuRZ1yGyj6pn8GU33c/yn+krddTUkVCwTbVatbalW5jhQjDbHYym/JcxaK9ZS/3JTeGcWrBgiPqHEEDhCf26vPZsXoMSeVCEORVKTp1BSg=
+  - secure: "eoWlW9GyTJY04P8K3pxayXwU9/hmptQg/LfirispQkV9YvmziCfSzXnatnBhNfud98sCzY8BScXnb+OWLTnjLKpId4rtEqb0aJ40Jc32cUKzgzFAUn7cNcDAbUIfyPAGVqyQqfj/11wYSADwWMMOPlW97ExUtoyiH2WenXuRHso="
   
 before_install:
 - export DISPLAY=:99.0
 - sh -e /etc/init.d/xvfb start
 
+# default install command is just "mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V"
+install:
+- mvn install -DskipTests=true -Dmaven.javadoc.skip=true -B -V -e
+
 after_success:
-- mvn clean test jacoco:report coveralls:report
+- mvn clean org.jacoco:jacoco-maven-plugin:prepare-agent package sonar:sonar -Dsonar.host.url=https://sonarqube.com -Dsonar.login=$SONAR_TOKEN
 - bash update-ghpages.sh
 
-sudo: false
+# use latest java version available instead of travis default
+addons:
+  apt:
+    packages:
+      - oracle-java8-installer
+
+notifications:
+  email:
+    - iluwatar@gmail.com
+  webhooks:
+    urls:
+      - https://webhooks.gitter.im/e/3319623945358a093a6f
+    on_success: change  # options: [always|never|change] default: always
+    on_failure: always  # options: [always|never|change] default: always
+    on_start: never     # options: [always|never|change] default: always
+
+sudo: required

README.md

@@ -5,8 +5,9 @@
 # Design patterns implemented in Java
 
 [![Build status](https://travis-ci.org/iluwatar/java-design-patterns.svg?branch=master)](https://travis-ci.org/iluwatar/java-design-patterns)
-[![Coverage Status](https://coveralls.io/repos/iluwatar/java-design-patterns/badge.svg?branch=master)](https://coveralls.io/r/iluwatar/java-design-patterns?branch=master)
+[![License MIT](https://img.shields.io/badge/license-MIT-blue.svg)](https://raw.githubusercontent.com/iluwatar/java-design-patterns/master/LICENSE.md)
 [![Join the chat at https://gitter.im/iluwatar/java-design-patterns](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/iluwatar/java-design-patterns?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+[![Quality Gate](https://sonarqube.com/api/badges/gate?key=com.iluwatar%3Ajava-design-patterns)](https://sonarqube.com/dashboard/index/com.iluwatar%3Ajava-design-patterns)
 
 # Introduction
 
@@ -23,7 +24,7 @@ are familiar with the patterns.
 # Getting started
 
 Before you dive into the material, you should be familiar with various
-[Programming/Software Design Principles](http://webpro.github.io/programming-principles/).
+Programming/Software Design Principles.
 
 All designs should be as simple as possible. You should start with KISS, YAGNI,
 and Do The Simplest Thing That Could Possibly Work principles. Complexity and

_scripts/postPumlsToServer.py

@@ -0,0 +1,67 @@
+#
+# The MIT License
+# Copyright (c) 2014-2016 Ilkka Seppälä
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+#
+
+import requests, glob, re, os
+
+# taken from here: http://stackoverflow.com/a/13641746
+def replace(file, pattern, subst):
+    # Read contents from file as a single string
+    file_handle = open(file, 'r')
+    file_string = file_handle.read()
+    file_handle.close()
+
+    # Use RE package to allow for replacement (also allowing for (multiline) REGEX)
+    file_string = (re.sub(pattern, subst, file_string))
+
+    # Write contents to file.
+    # Using mode 'w' truncates the file.
+    file_handle = open(file, 'w')
+    file_handle.write(file_string)
+    file_handle.close()
+
+# list of all puml files
+fileList = glob.glob('*/etc/*.puml')
+for puml in fileList:
+    pathSplit = puml.split("/")
+    # parent folder
+    parent = pathSplit[0]
+    # individual artifact/project name
+    artifact = pathSplit[2].replace(".urm.puml", "")
+    print "parent: " + parent + "; artifact: " + artifact
+
+    # do a POST to the official plantuml hosting site with a little trick "!includeurl" and raw github content
+    data = {
+        'text': "!includeurl https://raw.githubusercontent.com/iluwatar/java-design-patterns/master/" + puml
+    }
+    r = requests.post('http://plantuml.com/plantuml/uml', data=data)
+    pumlId = r.url.replace("http://plantuml.com/plantuml/uml/", "")
+    
+    # the only thing needed to get a png/svg/ascii from the server back
+    print "Puml Server ID: " + pumlId
+    
+    # add the id so jekyll/liquid can use it
+    if (parent == artifact):
+        replace("./" + parent + "/README.md", "categories:", "pumlid: {}\\ncategories:".format(pumlId))
+    else:
+        print "I dont want to program this, just add the following lines to the README.md file that corresponds to this puml file '" + puml + "'\npumlid: {}".format(pumlId)
+

abstract-document/README.md

@@ -0,0 +1,32 @@
+---
+layout: pattern
+title: Abstract Document
+folder: abstract-document
+permalink: /patterns/abstract-document/
+pumlid: PSjB3eCm34NHhPG599vtDyQn85L-ifzX-p3lxEf8Twj3MXGDQvyJMFubChxpKN767gucSq07iinEjSNDOACVNvoAUZr6MWoe3QVE_WRnxZ0Mf38b-hkIGlurX_MyehS7
+categories: Structural
+tags: 
+ - Java
+ - Difficulty-Intermediate
+---
+
+## Intent
+Achieve flexibility of untyped languages and keep the type-safety 
+
+![alt text](./etc/abstract-document-base.png "Abstract Document Base")
+
+![alt text](./etc/abstract-document.png "Abstract Document Traits and Domain")
+
+
+## Applicability
+Use the Abstract Document Pattern when
+
+* there is a need to add new properties on the fly
+* you want a flexible way to organize domain in tree like structure
+* you want more loosely coupled system
+
+
+## Credits
+
+* [Wikipedia: Abstract Document Pattern](https://en.wikipedia.org/wiki/Abstract_Document_Pattern)
+* [Martin Fowler: Dealing with properties](http://martinfowler.com/apsupp/properties.pdf)

abstract-document/etc/abstract-document-base.ucls

@@ -0,0 +1,58 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<class-diagram version="1.1.9" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true" 
+  realizations="true" associations="true" dependencies="false" nesting-relationships="true" router="FAN">  
+  <interface id="1" language="java" name="com.iluwatar.abstractdocument.Document" project="design-patterns" 
+    file="/design-patterns/src/com/iluwatar/abstractdocument/Document.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="249" y="405"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <class id="2" language="java" name="com.iluwatar.abstractdocument.AbstractDocument" project="design-patterns" 
+    file="/design-patterns/src/com/iluwatar/abstractdocument/AbstractDocument.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="250" y="237"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <class id="3" language="java" name="com.iluwatar.abstractdocument.domain.Car" project="design-patterns" 
+    file="/design-patterns/src/com/iluwatar/abstractdocument/domain/Car.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="108" y="75"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <class id="4" language="java" name="com.iluwatar.abstractdocument.domain.Part" project="design-patterns" 
+    file="/design-patterns/src/com/iluwatar/abstractdocument/domain/Part.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="400" y="76"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <generalization id="5">    
+    <end type="SOURCE" refId="4"/>    
+    <end type="TARGET" refId="2"/>  
+  </generalization>  
+  <realization id="6">    
+    <end type="SOURCE" refId="2"/>    
+    <end type="TARGET" refId="1"/>  
+  </realization>  
+  <generalization id="7">    
+    <end type="SOURCE" refId="3"/>    
+    <end type="TARGET" refId="2"/>  
+  </generalization>  
+  <classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+    sort-features="false" accessors="true" visibility="true">    
+    <attributes public="true" package="true" protected="true" private="true" static="true"/>    
+    <operations public="true" package="true" protected="true" private="true" static="true"/>  
+  </classifier-display>  
+  <association-display labels="true" multiplicity="true"/>
+</class-diagram>

abstract-document/etc/abstract-document.ucls

@@ -1,84 +1,92 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<class-diagram version="1.1.8" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true" 
-  realizations="true" associations="true" dependencies="false" nesting-relationships="true">  
-  <class id="1" language="java" name="com.iluwatar.facade.DwarvenGoldmineFacade" project="facade" 
-    file="/facade/src/main/java/com/iluwatar/facade/DwarvenGoldmineFacade.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="160" width="376" x="50" y="263"/>    
+<class-diagram version="1.1.9" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true" 
+  realizations="true" associations="true" dependencies="false" nesting-relationships="true" router="FAN">  
+  <interface id="1" language="java" name="com.iluwatar.abstractdocument.Document" project="design-patterns" 
+    file="/design-patterns/src/com/iluwatar/abstractdocument/Document.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="341" y="376"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <interface id="2" language="java" name="com.iluwatar.abstractdocument.domain.HasModel" project="design-patterns" 
+    file="/design-patterns/src/com/iluwatar/abstractdocument/domain/HasModel.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="81" width="173" x="41" y="194"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <interface id="3" language="java" name="com.iluwatar.abstractdocument.domain.HasPrice" project="design-patterns" 
+    file="/design-patterns/src/com/iluwatar/abstractdocument/domain/HasPrice.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="81" width="175" x="254" y="194"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <interface id="4" language="java" name="com.iluwatar.abstractdocument.domain.HasParts" project="design-patterns" 
+    file="/design-patterns/src/com/iluwatar/abstractdocument/domain/HasParts.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="81" width="173" x="469" y="194"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <class id="5" language="java" name="com.iluwatar.abstractdocument.domain.Car" project="design-patterns" 
+    file="/design-patterns/src/com/iluwatar/abstractdocument/domain/Car.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="99" width="173" x="254" y="37"/>    
     <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
       sort-features="false" accessors="true" visibility="true">      
       <attributes public="true" package="true" protected="true" private="true" static="true"/>      
       <operations public="true" package="true" protected="true" private="true" static="true"/>    
     </display>  
   </class>  
-  <class id="2" language="java" name="com.iluwatar.facade.DwarvenMineWorker" project="facade" 
-    file="/facade/src/main/java/com/iluwatar/facade/DwarvenMineWorker.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="231" width="171" x="50" y="463"/>    
+  <class id="6" language="java" name="com.iluwatar.abstractdocument.domain.Part" project="design-patterns" 
+    file="/design-patterns/src/com/iluwatar/abstractdocument/domain/Part.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="99" width="173" x="41" y="37"/>    
     <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
       sort-features="false" accessors="true" visibility="true">      
       <attributes public="true" package="true" protected="true" private="true" static="true"/>      
       <operations public="true" package="true" protected="true" private="true" static="true"/>    
     </display>  
   </class>  
-  <class id="3" language="java" name="com.iluwatar.facade.DwarvenCartOperator" project="facade" 
-    file="/facade/src/main/java/com/iluwatar/facade/DwarvenCartOperator.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="124" width="181" x="-272" y="734"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <class id="4" language="java" name="com.iluwatar.facade.DwarvenGoldDigger" project="facade" 
-    file="/facade/src/main/java/com/iluwatar/facade/DwarvenGoldDigger.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="124" width="169" x="-51" y="734"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <enumeration id="5" language="java" name="com.iluwatar.facade.DwarvenMineWorker.Action" project="facade" 
-    file="/facade/src/main/java/com/iluwatar/facade/DwarvenMineWorker.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="178" width="164" x="158" y="734"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </enumeration>  
-  <class id="6" language="java" name="com.iluwatar.facade.DwarvenTunnelDigger" project="facade" 
-    file="/facade/src/main/java/com/iluwatar/facade/DwarvenTunnelDigger.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="124" width="184" x="362" y="734"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <generalization id="7">    
+  <realization id="7">    
+    <end type="SOURCE" refId="5"/>    
+    <end type="TARGET" refId="2"/>  
+  </realization>  
+  <realization id="8">    
     <end type="SOURCE" refId="6"/>    
     <end type="TARGET" refId="2"/>  
-  </generalization>  
-  <generalization id="8">    
-    <end type="SOURCE" refId="4"/>    
-    <end type="TARGET" refId="2"/>  
-  </generalization>  
+  </realization>  
   <generalization id="9">    
-    <end type="SOURCE" refId="3"/>    
-    <end type="TARGET" refId="2"/>  
-  </generalization>  
-  <association id="10">    
-    <end type="SOURCE" refId="1" navigable="false">      
-      <attribute id="11" name="workers"/>      
-      <multiplicity id="12" minimum="0" maximum="2147483647"/>    
-    </end>    
-    <end type="TARGET" refId="2" navigable="true"/>    
-    <display labels="true" multiplicity="true"/>  
-  </association>  
-  <nesting id="13">    
     <end type="SOURCE" refId="2"/>    
-    <end type="TARGET" refId="5"/>  
-  </nesting>  
+    <end type="TARGET" refId="1"/>  
+  </generalization>  
+  <realization id="10">    
+    <end type="SOURCE" refId="5"/>    
+    <end type="TARGET" refId="3"/>  
+  </realization>  
+  <realization id="11">    
+    <end type="SOURCE" refId="5"/>    
+    <end type="TARGET" refId="4"/>  
+  </realization>  
+  <generalization id="12">    
+    <end type="SOURCE" refId="3"/>    
+    <end type="TARGET" refId="1"/>  
+  </generalization>  
+  <generalization id="13">    
+    <end type="SOURCE" refId="4"/>    
+    <end type="TARGET" refId="1"/>  
+  </generalization>  
+  <realization id="14">    
+    <end type="SOURCE" refId="6"/>    
+    <end type="TARGET" refId="3"/>  
+  </realization>  
   <classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
     sort-features="false" accessors="true" visibility="true">    
     <attributes public="true" package="true" protected="true" private="true" static="true"/>    

abstract-document/etc/abstract-document.urm.puml

@@ -0,0 +1,59 @@
+@startuml
+package com.iluwatar.abstractdocument.domain {
+  class Car {
+    + Car(properties : Map<String, Object>)
+  }
+  interface HasModel {
+    + PROPERTY : String {static}
+    + getModel() : Optional<String>
+  }
+  interface HasParts {
+    + PROPERTY : String {static}
+    + getParts() : Stream<Part>
+  }
+  interface HasPrice {
+    + PROPERTY : String {static}
+    + getPrice() : Optional<Number>
+  }
+  interface HasType {
+    + PROPERTY : String {static}
+    + getType() : Optional<String>
+  }
+  class Part {
+    + Part(properties : Map<String, Object>)
+  }
+}
+package com.iluwatar.abstractdocument {
+  abstract class AbstractDocument {
+    - properties : Map<String, Object>
+    # AbstractDocument(properties : Map<String, Object>)
+    + children(key : String, constructor : Function<Map<String, Object>, T>) : Stream<T>
+    + get(key : String) : Object
+    + put(key : String, value : Object)
+    + toString() : String
+  }
+  class App {
+    - LOGGER : Logger {static}
+    + App()
+    + main(args : String[]) {static}
+  }
+  interface Document {
+    + children(String, Function<Map<String, Object>, T>) : Stream<T> {abstract}
+    + get(String) : Object {abstract}
+    + put(String, Object) {abstract}
+  }
+}
+AbstractDocument ..|> Document 
+Car ..|> HasModel 
+Car ..|> HasPrice 
+Car ..|> HasParts 
+Car --|> AbstractDocument 
+HasModel --|> Document 
+HasParts --|> Document 
+HasPrice --|> Document 
+HasType --|> Document 
+Part ..|> HasType 
+Part ..|> HasModel 
+Part ..|> HasPrice 
+Part --|> AbstractDocument 
+@enduml

abstract-document/pom.xml

@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    The MIT License
+    Copyright (c) 2014-2016 Ilkka Seppälä
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <artifactId>java-design-patterns</artifactId>
+        <groupId>com.iluwatar</groupId>
+        <version>1.17.0</version>
+    </parent>
+    <artifactId>abstract-document</artifactId>
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+</project>

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

@@ -0,0 +1,72 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.abstractdocument;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.function.Function;
+import java.util.stream.Stream;
+
+/**
+ * Abstract implementation of Document interface
+ */
+public abstract class AbstractDocument implements Document {
+
+  private final Map<String, Object> properties;
+
+  protected AbstractDocument(Map<String, Object> properties) {
+    Objects.requireNonNull(properties, "properties map is required");
+    this.properties = properties;
+  }
+
+  @Override
+  public Void put(String key, Object value) {
+    properties.put(key, value);
+    return null;
+  }
+
+  @Override
+  public Object get(String key) {
+    return properties.get(key);
+  }
+
+  @Override
+  public <T> Stream<T> children(String key, Function<Map<String, Object>, T> constructor) {
+    Optional<List<Map<String, Object>>> any = Stream.of(get(key)).filter(el -> el != null)
+        .map(el -> (List<Map<String, Object>>) el).findAny();
+    return any.isPresent() ? any.get().stream().map(constructor) : Stream.empty();
+  }
+
+  @Override
+  public String toString() {
+    StringBuilder builder = new StringBuilder();
+    builder.append(getClass().getName()).append("[");
+    properties.entrySet()
+        .forEach(e -> builder.append("[").append(e.getKey()).append(" : ").append(e.getValue()).append("]"));
+    builder.append("]");
+    return builder.toString();
+  }
+
+}

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

@@ -0,0 +1,91 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.abstractdocument;
+
+import com.iluwatar.abstractdocument.domain.Car;
+import com.iluwatar.abstractdocument.domain.HasModel;
+import com.iluwatar.abstractdocument.domain.HasParts;
+import com.iluwatar.abstractdocument.domain.HasPrice;
+import com.iluwatar.abstractdocument.domain.HasType;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * The Abstract Document pattern enables handling additional, non-static
+ * properties. This pattern uses concept of traits to enable type safety and
+ * separate properties of different classes into set of interfaces.
+ * <p>
+ * <p>
+ * In Abstract Document pattern,({@link AbstractDocument}) fully implements
+ * {@link Document}) interface. Traits are then defined to enable access to
+ * properties in usual, static way.
+ */
+public class App {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
+
+  /**
+   * Executes the App
+   */
+  public App() {
+    LOGGER.info("Constructing parts and car");
+
+    Map<String, Object> carProperties = new HashMap<>();
+    carProperties.put(HasModel.PROPERTY, "300SL");
+    carProperties.put(HasPrice.PROPERTY, 10000L);
+
+    Map<String, Object> wheelProperties = new HashMap<>();
+    wheelProperties.put(HasType.PROPERTY, "wheel");
+    wheelProperties.put(HasModel.PROPERTY, "15C");
+    wheelProperties.put(HasPrice.PROPERTY, 100L);
+
+    Map<String, Object> doorProperties = new HashMap<>();
+    doorProperties.put(HasType.PROPERTY, "door");
+    doorProperties.put(HasModel.PROPERTY, "Lambo");
+    doorProperties.put(HasPrice.PROPERTY, 300L);
+
+    carProperties.put(HasParts.PROPERTY, Arrays.asList(wheelProperties, doorProperties));
+
+    Car car = new Car(carProperties);
+
+    LOGGER.info("Here is our car:");
+    LOGGER.info("-> model: {}", car.getModel().get());
+    LOGGER.info("-> price: {}", car.getPrice().get());
+    LOGGER.info("-> parts: ");
+    car.getParts().forEach(p -> LOGGER.info("\t{}/{}/{}", p.getType().get(), p.getModel().get(), p.getPrice().get()));
+  }
+
+  /**
+   * Program entry point
+   *
+   * @param args command line args
+   */
+  public static void main(String[] args) {
+    new App();
+  }
+
+}

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

@@ -0,0 +1,59 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.abstractdocument;
+
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Stream;
+
+/**
+ * Document interface
+ */
+public interface Document {
+
+  /**
+   * Puts the value related to the key
+   *
+   * @param key   element key
+   * @param value element value
+   * @return Void
+   */
+  Void put(String key, Object value);
+
+  /**
+   * Gets the value for the key
+   *
+   * @param key element key
+   * @return value or null
+   */
+  Object get(String key);
+
+  /**
+   * Gets the stream of child documents
+   *
+   * @param key         element key
+   * @param constructor constructor of child class
+   * @return child documents
+   */
+  <T> Stream<T> children(String key, Function<Map<String, Object>, T> constructor);
+}

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/Car.java

@@ -0,0 +1,38 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.abstractdocument.domain;
+
+import java.util.Map;
+
+import com.iluwatar.abstractdocument.AbstractDocument;
+
+/**
+ * Car entity
+ */
+public class Car extends AbstractDocument implements HasModel, HasPrice, HasParts {
+
+  public Car(Map<String, Object> properties) {
+    super(properties);
+  }
+
+}

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasModel.java

@@ -0,0 +1,40 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.abstractdocument.domain;
+
+import java.util.Optional;
+
+import com.iluwatar.abstractdocument.Document;
+
+/**
+ * HasModel trait for static access to 'model' property
+ */
+public interface HasModel extends Document {
+
+  String PROPERTY = "model";
+
+  default Optional<String> getModel() {
+    return Optional.ofNullable((String) get(PROPERTY));
+  }
+
+}

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasParts.java

@@ -0,0 +1,40 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.abstractdocument.domain;
+
+import java.util.stream.Stream;
+
+import com.iluwatar.abstractdocument.Document;
+
+/**
+ * HasParts trait for static access to 'parts' property
+ */
+public interface HasParts extends Document {
+
+  String PROPERTY = "parts";
+
+  default Stream<Part> getParts() {
+    return children(PROPERTY, Part::new);
+  }
+
+}

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasPrice.java

@@ -0,0 +1,40 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.abstractdocument.domain;
+
+import java.util.Optional;
+
+import com.iluwatar.abstractdocument.Document;
+
+/**
+ * HasPrice trait for static access to 'price' property
+ */
+public interface HasPrice extends Document {
+
+  String PROPERTY = "price";
+
+  default Optional<Number> getPrice() {
+    return Optional.ofNullable((Number) get(PROPERTY));
+  }
+
+}

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/HasType.java

@@ -0,0 +1,40 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.abstractdocument.domain;
+
+import com.iluwatar.abstractdocument.Document;
+
+import java.util.Optional;
+
+/**
+ * HasType trait for static access to 'type' property
+ */
+public interface HasType extends Document {
+
+  String PROPERTY = "type";
+
+  default Optional<String> getType() {
+    return Optional.ofNullable((String) get(PROPERTY));
+  }
+
+}

abstract-document/src/main/java/com/iluwatar/abstractdocument/domain/Part.java

@@ -0,0 +1,38 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.abstractdocument.domain;
+
+import java.util.Map;
+
+import com.iluwatar.abstractdocument.AbstractDocument;
+
+/**
+ * Part entity
+ */
+public class Part extends AbstractDocument implements HasType, HasModel, HasPrice {
+
+  public Part(Map<String, Object> properties) {
+    super(properties);
+  }
+
+}

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

@@ -0,0 +1,88 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.abstractdocument;
+
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Stream;
+
+import static junit.framework.TestCase.assertEquals;
+import static junit.framework.TestCase.assertNotNull;
+
+/**
+ * AbstractDocument test class
+ */
+public class AbstractDocumentTest {
+
+  private static final String KEY = "key";
+  private static final String VALUE = "value";
+
+  private class DocumentImplementation extends AbstractDocument {
+
+    DocumentImplementation(Map<String, Object> properties) {
+      super(properties);
+    }
+  }
+
+  private DocumentImplementation document = new DocumentImplementation(new HashMap<>());
+
+  @Test
+  public void shouldPutAndGetValue() {
+    document.put(KEY, VALUE);
+    assertEquals(VALUE, document.get(KEY));
+  }
+
+  @Test
+  public void shouldRetrieveChildren() {
+    Map<String, Object> child1 = new HashMap<>();
+    Map<String, Object> child2 = new HashMap<>();
+    List<Map<String, Object>> children = Arrays.asList(child1, child2);
+
+    document.put(KEY, children);
+
+    Stream<DocumentImplementation> childrenStream = document.children(KEY, DocumentImplementation::new);
+    assertNotNull(children);
+    assertEquals(2, childrenStream.count());
+  }
+
+  @Test
+  public void shouldRetrieveEmptyStreamForNonExistingChildren() {
+    Stream<DocumentImplementation> children = document.children(KEY, DocumentImplementation::new);
+    assertNotNull(children);
+    assertEquals(0, children.count());
+  }
+
+  @Test
+  public void shouldIncludePropsInToString() {
+    Map<String, Object> props = new HashMap<>();
+    props.put(KEY, VALUE);
+    DocumentImplementation document = new DocumentImplementation(props);
+    assertNotNull(document.toString().contains(KEY));
+    assertNotNull(document.toString().contains(VALUE));
+  }
+
+}

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

@@ -0,0 +1,37 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.abstractdocument;
+
+import org.junit.Test;
+
+/**
+ * Simple App test
+ */
+public class AppTest {
+
+  @Test
+  public void shouldExecuteAppWithoutException() {
+    App.main(null);
+  }
+
+}

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

@@ -0,0 +1,77 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.abstractdocument;
+
+import com.iluwatar.abstractdocument.domain.Car;
+import com.iluwatar.abstractdocument.domain.HasModel;
+import com.iluwatar.abstractdocument.domain.HasParts;
+import com.iluwatar.abstractdocument.domain.HasPrice;
+import com.iluwatar.abstractdocument.domain.HasType;
+import com.iluwatar.abstractdocument.domain.Part;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+
+import static junit.framework.TestCase.assertEquals;
+
+/**
+ * Test for Part and Car
+ */
+public class DomainTest {
+
+  private static final String TEST_PART_TYPE = "test-part-type";
+  private static final String TEST_PART_MODEL = "test-part-model";
+  private static final long TEST_PART_PRICE = 0L;
+
+  private static final String TEST_CAR_MODEL = "test-car-model";
+  private static final long TEST_CAR_PRICE = 1L;
+
+  @Test
+  public void shouldConstructPart() {
+    Map<String, Object> partProperties = new HashMap<>();
+    partProperties.put(HasType.PROPERTY, TEST_PART_TYPE);
+    partProperties.put(HasModel.PROPERTY, TEST_PART_MODEL);
+    partProperties.put(HasPrice.PROPERTY, TEST_PART_PRICE);
+    Part part = new Part(partProperties);
+
+    assertEquals(TEST_PART_TYPE, part.getType().get());
+    assertEquals(TEST_PART_MODEL, part.getModel().get());
+    assertEquals(TEST_PART_PRICE, part.getPrice().get());
+  }
+
+  @Test
+  public void shouldConstructCar() {
+    Map<String, Object> carProperties = new HashMap<>();
+    carProperties.put(HasModel.PROPERTY, TEST_CAR_MODEL);
+    carProperties.put(HasPrice.PROPERTY, TEST_CAR_PRICE);
+    carProperties.put(HasParts.PROPERTY, Arrays.asList(new HashMap<>(), new HashMap<>()));
+    Car car = new Car(carProperties);
+
+    assertEquals(TEST_CAR_MODEL, car.getModel().get());
+    assertEquals(TEST_CAR_PRICE, car.getPrice().get());
+    assertEquals(2, car.getParts().count());
+  }
+
+}

abstract-factory/README.md

@@ -3,8 +3,9 @@ layout: pattern
 title: Abstract Factory
 folder: abstract-factory
 permalink: /patterns/abstract-factory/
+pumlid: PSZB3OD034NHLa81Czwd6sCC39gVxEUWT1_ssLmTtQLqgR5fM7sTmFGtaV6TZu8prd0r6HtQaMKqAZLk1XjT_E6qgPUZfyc0MdTgx0-8LuUn8ErFXdr98NypXxKyezKV
 categories: Creational
-tags: 
+tags:
  - Java
  - Gang Of Four
  - Difficulty-Intermediate
@@ -17,7 +18,107 @@ Kit
 Provide an interface for creating families of related or dependent
 objects without specifying their concrete classes.
 
-![alt text](./etc/abstract-factory_1.png "Abstract Factory")
+## Explanation
+Real world example
+
+> To create a kingdom we need objects with common theme. Elven kingdom needs an Elven king, Elven castle and Elven army whereas Orcish kingdom needs an Orcish king, Orcish castle and Orcish army. There is a dependency between the objects in the kingdom.
+
+In plain words
+
+> A factory of factories; a factory that groups the individual but related/dependent factories together without specifying their concrete classes.
+
+Wikipedia says
+
+> The abstract factory pattern provides a way to encapsulate a group of individual factories that have a common theme without specifying their concrete classes
+
+**Programmatic Example**
+
+Translating the kingdom example above. First of all we have some interfaces and implementation for the objects in the kingdom
+
+```
+public interface Castle {
+  String getDescription();
+}
+public interface King {
+  String getDescription();
+}
+public interface Army {
+  String getDescription();
+}
+
+// Elven implementations ->
+public class ElfCastle implements Castle {
+  static final String DESCRIPTION = "This is the Elven castle!";
+  @Override
+  public String getDescription() {
+    return DESCRIPTION;
+  }
+}
+public class ElfKing implements King {
+  static final String DESCRIPTION = "This is the Elven king!";
+  @Override
+  public String getDescription() {
+    return DESCRIPTION;
+  }
+}
+public class ElfArmy implements Army {
+  static final String DESCRIPTION = "This is the Elven Army!";
+  @Override
+  public String getDescription() {
+    return DESCRIPTION;
+  }
+}
+
+// Orcish implementations similarly...
+
+```
+
+Then we have the abstraction and implementations for the kingdom factory
+
+```
+public interface KingdomFactory {
+  Castle createCastle();
+  King createKing();
+  Army createArmy();
+}
+
+public class ElfKingdomFactory implements KingdomFactory {
+  public Castle createCastle() {
+    return new ElfCastle();
+  }
+  public King createKing() {
+    return new ElfKing();
+  }
+  public Army createArmy() {
+    return new ElfArmy();
+  }
+}
+
+public class OrcKingdomFactory implements KingdomFactory {
+  public Castle createCastle() {
+    return new OrcCastle();
+  }
+  public King createKing() {
+    return new OrcKing();
+  }
+  public Army createArmy() {
+    return new OrcArmy();
+  }
+}
+```
+
+Now we have our abstract factory that lets us make family of related objects i.e. Elven kingdom factory creates Elven castle, king and army etc.
+
+```
+KingdomFactory factory = new ElfKingdomFactory();
+Castle castle = factory.createCastle();
+King king = factory.createKing();
+Army army = factory.createArmy();
+
+castle.getDescription();  // Output: This is the Elven castle!
+king.getDescription(); // Output: This is the Elven king!
+army.getDescription(); // Output: This is the Elven Army!
+```
 
 ## Applicability
 Use the Abstract Factory pattern when
@@ -26,10 +127,25 @@ Use the Abstract Factory pattern when
 * a system should be configured with one of multiple families of products
 * a family of related product objects is designed to be used together, and you need to enforce this constraint
 * you want to provide a class library of products, and you want to reveal just their interfaces, not their implementations
+* the lifetime of the dependency is conceptually shorter than the lifetime of the consumer.
+*	you need a run-time value to construct a particular dependency
+*	you want to decide which product to call from a family at runtime.
+*	you need to supply one or more parameters only known at run-time before you can resolve a dependency.
+
+## Use Cases:	
+
+*	Selecting to call the appropriate implementation of FileSystemAcmeService or DatabaseAcmeService or NetworkAcmeService at runtime.
+*	Unit test case writing becomes much easier
+
+## Consequences:
+
+*	Dependency injection in java hides the service class dependencies that can lead to runtime errors that would have been caught at compile time.
 
 ## Real world examples
 
 * [javax.xml.parsers.DocumentBuilderFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/parsers/DocumentBuilderFactory.html)
+* [javax.xml.transform.TransformerFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/transform/TransformerFactory.html#newInstance--)
+* [javax.xml.xpath.XPathFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/xpath/XPathFactory.html#newInstance--)
 
 ## Credits
 

abstract-factory/etc/abstract-factory.ucls

@@ -1,159 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<class-diagram version="1.1.8" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true" 
-  realizations="true" associations="true" dependencies="false" nesting-relationships="true">  
-  <interface id="1" language="java" name="com.iluwatar.abstractfactory.Army" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/Army.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="70" width="161" x="1407" y="300"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </interface>  
-  <interface id="2" language="java" name="com.iluwatar.abstractfactory.KingdomFactory" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/KingdomFactory.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="124" width="161" x="1001" y="300"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </interface>  
-  <class id="3" language="java" name="com.iluwatar.abstractfactory.ElfCastle" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfCastle.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="106" width="161" x="96" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <class id="4" language="java" name="com.iluwatar.abstractfactory.ElfKingdomFactory" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKingdomFactory.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="142" width="161" x="900" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <class id="5" language="java" name="com.iluwatar.abstractfactory.ElfKing" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfKing.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="106" width="161" x="498" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <interface id="6" language="java" name="com.iluwatar.abstractfactory.King" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/King.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="70" width="161" x="599" y="300"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </interface>  
-  <class id="7" language="java" name="com.iluwatar.abstractfactory.OrcCastle" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcCastle.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="106" width="161" x="297" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <class id="8" language="java" name="com.iluwatar.abstractfactory.OrcKing" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKing.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="106" width="161" x="699" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <class id="9" language="java" name="com.iluwatar.abstractfactory.ElfArmy" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/ElfArmy.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="106" width="161" x="1306" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <class id="10" language="java" name="com.iluwatar.abstractfactory.OrcArmy" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcArmy.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="106" width="161" x="1507" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <interface id="11" language="java" name="com.iluwatar.abstractfactory.Castle" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/Castle.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="70" width="161" x="197" y="300"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </interface>  
-  <class id="12" language="java" name="com.iluwatar.abstractfactory.OrcKingdomFactory" project="abstract-factory" 
-    file="/abstract-factory/src/main/java/com/iluwatar/abstractfactory/OrcKingdomFactory.java" binary="false" 
-    corner="BOTTOM_RIGHT">    
-    <position height="142" width="165" x="1101" y="118"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <realization id="13">    
-    <end type="SOURCE" refId="4"/>    
-    <end type="TARGET" refId="2"/>  
-  </realization>  
-  <realization id="14">    
-    <end type="SOURCE" refId="7"/>    
-    <end type="TARGET" refId="11"/>  
-  </realization>  
-  <realization id="15">    
-    <end type="SOURCE" refId="8"/>    
-    <end type="TARGET" refId="6"/>  
-  </realization>  
-  <realization id="16">    
-    <end type="SOURCE" refId="3"/>    
-    <end type="TARGET" refId="11"/>  
-  </realization>  
-  <realization id="17">    
-    <end type="SOURCE" refId="10"/>    
-    <end type="TARGET" refId="1"/>  
-  </realization>  
-  <realization id="18">    
-    <end type="SOURCE" refId="12"/>    
-    <end type="TARGET" refId="2"/>  
-  </realization>  
-  <realization id="19">    
-    <end type="SOURCE" refId="5"/>    
-    <end type="TARGET" refId="6"/>  
-  </realization>  
-  <realization id="20">    
-    <end type="SOURCE" refId="9"/>    
-    <end type="TARGET" refId="1"/>  
-  </realization>  
-  <classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-    sort-features="false" accessors="true" visibility="true">    
-    <attributes public="true" package="true" protected="true" private="true" static="true"/>    
-    <operations public="true" package="true" protected="true" private="true" static="true"/>  
-  </classifier-display>  
-  <association-display labels="true" multiplicity="true"/>
-</class-diagram>

abstract-factory/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright (c) 2014 Ilkka Seppälä
+    Copyright (c) 2014-2016 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
@@ -29,7 +29,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.11.0</version>
+    <version>1.17.0</version>
   </parent>
   <artifactId>abstract-factory</artifactId>
   <dependencies>

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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
@@ -22,6 +22,9 @@
  */
 package com.iluwatar.abstractfactory;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 /**
  * 
  * The Abstract Factory pattern provides a way to encapsulate a group of individual factories that have a common theme
@@ -39,6 +42,8 @@ package com.iluwatar.abstractfactory;
  */
 public class App {
 
+  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
+
   private King king;
   private Castle castle;
   private Army army;
@@ -98,17 +103,17 @@ public class App {
 
     App app = new App();
 
-    System.out.println("Elf Kingdom");
+    LOGGER.info("Elf Kingdom");
     app.createKingdom(new ElfKingdomFactory());
-    System.out.println(app.getArmy().getDescription());
-    System.out.println(app.getCastle().getDescription());
-    System.out.println(app.getKing().getDescription());
+    LOGGER.info(app.getArmy().getDescription());
+    LOGGER.info(app.getCastle().getDescription());
+    LOGGER.info(app.getKing().getDescription());
 
-    System.out.println("\nOrc Kingdom");
+    LOGGER.info("Orc Kingdom");
     app.createKingdom(new OrcKingdomFactory());
-    System.out.println(app.getArmy().getDescription());
-    System.out.println(app.getCastle().getDescription());
-    System.out.println(app.getKing().getDescription());
+    LOGGER.info(app.getArmy().getDescription());
+    LOGGER.info(app.getCastle().getDescription());
+    LOGGER.info(app.getKing().getDescription());
 
   }
 

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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
@@ -28,6 +28,9 @@ import static org.junit.Assert.assertTrue;
 import org.junit.Before;
 import org.junit.Test;
 
+/**
+ * Test for abstract factory
+ */
 public class AbstractFactoryTest {
 
   private App app = new App();

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

adapter/README.md

@@ -3,6 +3,7 @@ layout: pattern
 title: Adapter
 folder: adapter
 permalink: /patterns/adapter/
+pumlid: DSR14S8m30J0Lg20M7-wEMnDOiPMFDA9j0yyUEtUkzMHJTF7xI1NF4GSLzaxZtncgDVJgCPIpobzv0N2vOKtjgRHTziMI7KBcOXl10thfxB-Nz9dMJd71m00
 categories: Structural
 tags:
  - Java
@@ -18,7 +19,85 @@ Convert the interface of a class into another interface the clients
 expect. Adapter lets classes work together that couldn't otherwise because of
 incompatible interfaces.
 
-![alt text](./etc/adapter.png "Adapter")
+## Explanation
+
+Real world example
+
+> Consider that you have some pictures in your memory card and you need to transfer them to your computer. In order to transfer them you need some kind of adapter that is compatible with your computer ports so that you can attach memory card to your computer. In this case card reader is an adapter.
+> Another example would be the famous power adapter; a three legged plug can't be connected to a two pronged outlet, it needs to use a power adapter that makes it compatible with the two pronged outlet.
+> Yet another example would be a translator translating words spoken by one person to another
+
+In plain words
+
+> Adapter pattern lets you wrap an otherwise incompatible object in an adapter to make it compatible with another class.
+
+Wikipedia says
+
+> In software engineering, the adapter pattern is a software design pattern that allows the interface of an existing class to be used as another interface. It is often used to make existing classes work with others without modifying their source code.
+
+**Programmatic Example**
+
+Consider a captain that can only use rowing boats and cannot sail at all.
+
+First we have interfaces `RowingBoat` and `FishingBoat`
+
+```
+public interface RowingBoat {
+  void row();
+}
+
+public class FishingBoat {
+  private static final Logger LOGGER = LoggerFactory.getLogger(FishingBoat.class);
+  public void sail() {
+    LOGGER.info("The fishing boat is sailing");
+  }
+}
+```
+
+And captain expects an implementation of `RowingBoat` interface to be able to move
+
+```
+public class Captain implements RowingBoat {
+
+  private RowingBoat rowingBoat;
+
+  public Captain(RowingBoat rowingBoat) {
+    this.rowingBoat = rowingBoat;
+  }
+
+  @Override
+  public void row() {
+    rowingBoat.row();
+  }
+}
+```
+
+Now let's say the pirates are coming and our captain needs to escape but there is only fishing boat available. We need to create an adapter that allows the captain to operate the fishing boat with his rowing boat skills.
+
+```
+public class FishingBoatAdapter implements RowingBoat {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(FishingBoatAdapter.class);
+
+  private FishingBoat boat;
+
+  public FishingBoatAdapter() {
+    boat = new FishingBoat();
+  }
+
+  @Override
+  public void row() {
+    boat.sail();
+  }
+}
+```
+
+And now the `Captain` can use the `FishingBoat` to escape the pirates.
+
+```
+Captain captain = new Captain(new FishingBoatAdapter());
+captain.row();
+```
 
 ## Applicability
 Use the Adapter pattern when
@@ -26,10 +105,28 @@ Use the Adapter pattern when
 * you want to use an existing class, and its interface does not match the one you need
 * you want to create a reusable class that cooperates with unrelated or unforeseen classes, that is, classes that don't necessarily have compatible interfaces
 * you need to use several existing subclasses, but it's impractical to adapt their interface by subclassing every one. An object adapter can adapt the interface of its parent class.
+* most of the applications using third party libraries use adapters as a middle layer between the application and the 3rd party library to decouple the application from the library. If another library has to be used only an adapter for the new library is required without having to change the application code.
+
+## Consequences:
+Class and object adapters have different trade-offs. A class adapter
+
+*	adapts Adaptee to Target by committing to a concrete Adaptee class. As a consequence, a class adapter won’t work when we want to adapt a class and all its subclasses.
+*	let’s Adapter override some of Adaptee’s behavior, since Adapter is a subclass of Adaptee.
+*	introduces only one object, and no additional pointer indirection is needed to get to the adaptee.
+
+An object adapter	
+
+*	let’s a single Adapter work with many Adaptees—that is, the Adaptee itself and all of its subclasses (if any). The Adapter can also add functionality to all Adaptees at once.
+*	makes it harder to override Adaptee behavior. It will require subclassing Adaptee and making Adapter refer to the subclass rather than the Adaptee itself.
+
 
 ## Real world examples
 
 * [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-)
+* [java.util.Collections#enumeration()](https://docs.oracle.com/javase/8/docs/api/java/util/Collections.html#enumeration-java.util.Collection-)
+* [javax.xml.bind.annotation.adapters.XMLAdapter](http://docs.oracle.com/javase/8/docs/api/javax/xml/bind/annotation/adapters/XmlAdapter.html#marshal-BoundType-)
+
 
 ## Credits
 

adapter/pom.xml

@@ -2,7 +2,7 @@
 <!--
 
     The MIT License
-    Copyright (c) 2014 Ilkka Seppälä
+    Copyright (c) 2014-2016 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
@@ -29,7 +29,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.11.0</version>
+    <version>1.17.0</version>
   </parent>
   <artifactId>adapter</artifactId>
   <dependencies>

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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
@@ -34,14 +34,14 @@ package com.iluwatar.adapter;
  * object. This example uses the object adapter approach.
  *
  * <p>
- * The Adapter ({@link BattleFishingBoat}) converts the interface of the adaptee class (
- * {@link FishingBoat}) into a suitable one expected by the client ( {@link BattleShip} ).
+ * The Adapter ({@link FishingBoatAdapter}) converts the interface of the adaptee class (
+ * {@link FishingBoat}) into a suitable one expected by the client ( {@link RowingBoat} ).
  *
  * <p>
  * The story of this implementation is this. <br>
- * Pirates are coming! we need a {@link BattleShip} to fight! We have a {@link FishingBoat} and our
+ * Pirates are coming! we need a {@link RowingBoat} to flee! We have a {@link FishingBoat} and our
  * captain. We have no time to make up a new ship! we need to reuse this {@link FishingBoat}. The
- * captain needs a battleship which can fire and move. The spec is in {@link BattleShip}. We will
+ * captain needs a rowing boat which he can operate. The spec is in {@link RowingBoat}. We will
  * use the Adapter pattern to reuse {@link FishingBoat}.
  *
  */
@@ -53,8 +53,8 @@ public class App {
    * @param args command line args
    */
   public static void main(String[] args) {
-    Captain captain = new Captain(new BattleFishingBoat());
-    captain.move();
-    captain.fire();
+    // The captain can only operate rowing boats but with adapter he is able to use fishing boats as well
+    Captain captain = new Captain(new FishingBoatAdapter());
+    captain.row();
   }
 }

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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
@@ -23,33 +23,26 @@
 package com.iluwatar.adapter;
 
 /**
- * The Captain uses {@link BattleShip} to fight. <br>
+ * The Captain uses {@link RowingBoat} to sail. <br>
  * This is the client in the pattern.
  */
-public class Captain implements BattleShip {
+public class Captain implements RowingBoat {
 
-  private BattleShip battleship;
+  private RowingBoat rowingBoat;
 
-  public Captain() {
+  public Captain() {}
 
+  public Captain(RowingBoat rowingBoat) {
+    this.rowingBoat = rowingBoat;
   }
 
-  public Captain(BattleShip battleship) {
-    this.battleship = battleship;
-  }
-
-  public void setBattleship(BattleShip battleship) {
-    this.battleship = battleship;
+  public void setRowingBoat(RowingBoat rowingBoat) {
+    this.rowingBoat = rowingBoat;
   }
 
   @Override
-  public void fire() {
-    battleship.fire();
-  }
-
-  @Override
-  public void move() {
-    battleship.move();
+  public void row() {
+    rowingBoat.row();
   }
 
 }

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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
@@ -22,19 +22,21 @@
  */
 package com.iluwatar.adapter;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 /**
  *
- * Device class (adaptee in the pattern). We want to reuse this class
+ * Device class (adaptee in the pattern). We want to reuse this class.
+ * Fishing boat moves by sailing.
  *
  */
 public class FishingBoat {
 
-  public void sail() {
-    System.out.println("The Boat is moving to that place");
-  }
+  private static final Logger LOGGER = LoggerFactory.getLogger(FishingBoat.class);
 
-  public void fish() {
-    System.out.println("fishing ...");
+  public void sail() {
+    LOGGER.info("The fishing boat is sailing");
   }
 
 }

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

@@ -0,0 +1,43 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package com.iluwatar.adapter;
+
+/**
+ *
+ * Adapter class. Adapts the interface of the device ({@link FishingBoat}) into {@link RowingBoat}
+ * interface expected by the client ({@link Captain}).
+ *
+ */
+public class FishingBoatAdapter implements RowingBoat {
+
+  private FishingBoat boat;
+
+  public FishingBoatAdapter() {
+    boat = new FishingBoat();
+  }
+
+  @Override
+  public void row() {
+    boat.sail();
+  }
+}

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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
@@ -24,13 +24,11 @@ package com.iluwatar.adapter;
 
 /**
  * The interface expected by the client.<br>
- * A Battleship can fire and move.
+ * A rowing boat is rowed to move.
  *
  */
-public interface BattleShip {
+public interface RowingBoat {
 
-  void fire();
-
-  void move();
+  void row();
 
 }

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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
@@ -39,9 +39,9 @@ public class AdapterPatternTest {
 
   private Map<String, Object> beans;
 
-  private static final String BATTLESHIP_BEAN = "engineer";
+  private static final String FISHING_BEAN = "fisher";
 
-  private static final String CAPTAIN_BEAN = "captain";
+  private static final String ROWING_BEAN = "captain";
 
   /**
    * This method runs before the test execution and sets the bean objects in the beans Map.
@@ -50,34 +50,29 @@ public class AdapterPatternTest {
   public void setup() {
     beans = new HashMap<>();
 
-    BattleFishingBoat battleFishingBoat = spy(new BattleFishingBoat());
-    beans.put(BATTLESHIP_BEAN, battleFishingBoat);
+    FishingBoatAdapter fishingBoatAdapter = spy(new FishingBoatAdapter());
+    beans.put(FISHING_BEAN, fishingBoatAdapter);
 
     Captain captain = new Captain();
-    captain.setBattleship((BattleFishingBoat) beans.get(BATTLESHIP_BEAN));
-    beans.put(CAPTAIN_BEAN, captain);
+    captain.setRowingBoat((FishingBoatAdapter) beans.get(FISHING_BEAN));
+    beans.put(ROWING_BEAN, captain);
   }
 
   /**
-   * This test asserts that when we use the move() method on a captain bean(client), it is
-   * internally calling move method on the battleship object. The Adapter ({@link BattleFishingBoat}
+   * This test asserts that when we use the row() method on a captain bean(client), it is
+   * internally calling sail method on the fishing boat object. The Adapter ({@link FishingBoatAdapter}
    * ) converts the interface of the target class ( {@link FishingBoat}) into a suitable one
    * expected by the client ({@link Captain} ).
    */
   @Test
   public void testAdapter() {
-    BattleShip captain = (BattleShip) beans.get(CAPTAIN_BEAN);
+    RowingBoat captain = (RowingBoat) beans.get(ROWING_BEAN);
 
     // when captain moves
-    captain.move();
+    captain.row();
 
     // the captain internally calls the battleship object to move
-    BattleShip battleship = (BattleShip) beans.get(BATTLESHIP_BEAN);
-    verify(battleship).move();
-
-    // same with above with firing
-    captain.fire();
-    verify(battleship).fire();
-
+    RowingBoat adapter = (RowingBoat) beans.get(FISHING_BEAN);
+    verify(adapter).row();
   }
 }

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

@@ -1,6 +1,6 @@
 /**
  * The MIT License
- * Copyright (c) 2014 Ilkka Seppälä
+ * Copyright (c) 2014-2016 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

aggregator-microservices/README.md

@@ -0,0 +1,30 @@
+---
+layout: pattern
+title: Aggregator Microservices
+folder: aggregator-microservices
+permalink: /patterns/aggregator-microservices/
+pumlid: JOov3SCm301NIGQGs7iRXYPa1g8ayB7NjuiKwGvtmBrbKC-Tq_hhY5Y-0HXUjKaS-Kbdepc2HrIQ2jBpma23BvvOTdPfeooCO1iEYlu0O6l63MDQKI6Rp-CKOWSE-ey_NzEqhjH-0m00
+categories: Architectural
+tags:
+- Java
+- Spring
+---
+
+## Intent
+
+The user makes a single call to the Aggregator, and the aggregator then calls each relevant microservice and collects
+the data, apply business logic to it, and further publish is as a REST Endpoint.
+More variations of the aggregator are: 
+- Proxy Microservice Design Pattern: A different microservice is called upon the business need. 
+- Chained Microservice Design Pattern: In this case each microservice is dependent/ chained to a series 
+of other microservices.
+
+![alt text](./etc/aggregator-microservice.png "Aggregator Microservice")
+
+## Applicability
+
+Use the Aggregator Microservices pattern when you need a unified API for various microservices, regardless the client device.
+
+## Credits
+
+* [Microservice Design Patterns](http://blog.arungupta.me/microservice-design-patterns/)

aggregator-microservices/aggregator-service/pom.xml

@@ -0,0 +1,88 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    The MIT License
+    Copyright (c) 2014-2016 Ilkka Seppälä
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>aggregator-microservices</artifactId>
+        <groupId>com.iluwatar</groupId>
+        <version>1.17.0</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>aggregator-service</artifactId>
+    <packaging>jar</packaging>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-webmvc</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.httpcomponents</groupId>
+            <artifactId>httpclient</artifactId>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <version>${spring-boot.version}</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>repackage</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+</project>

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

@@ -0,0 +1,58 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.aggregator.microservices;
+
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import javax.annotation.Resource;
+
+/**
+ * The aggregator aggregates calls on various micro-services, collects
+ * data and further publishes them under a REST endpoint.
+ */
+@RestController
+public class Aggregator {
+
+
+  @Resource
+  private ProductInformationClient informationClient;
+
+  @Resource
+  private ProductInventoryClient inventoryClient;
+
+
+  /**
+   * Retrieves product data.
+   *
+   * @return a Product.
+   */
+  @RequestMapping("/product")
+  public Product getProduct() {
+    Product product = new Product();
+    product.setTitle(informationClient.getProductTitle());
+    product.setProductInventories(inventoryClient.getProductInventories());
+    return product;
+  }
+
+}

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

@@ -0,0 +1,42 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.aggregator.microservices;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * Spring Boot EntryPoint Class
+ */
+@SpringBootApplication
+public class App {
+
+  /**
+   * Program entry point
+   *
+   * @param args command line args
+   */
+  public static void main(String[] args) {
+    SpringApplication.run(App.class, args);
+  }
+}

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

@@ -0,0 +1,57 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.aggregator.microservices;
+
+/**
+ * Encapsulates all the data for a Product that clients will request.
+ */
+public class Product {
+
+  /**
+   * The title of the product.
+   */
+  private String title;
+
+
+  /**
+   * The inventories of the 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/ProductInformationClient.java

@@ -0,0 +1,32 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.aggregator.microservices;
+
+/**
+ * Interface for the Information micro-service.
+ */
+public interface ProductInformationClient {
+
+  String getProductTitle();
+
+}

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

@@ -0,0 +1,57 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.aggregator.microservices;
+
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClients;
+import org.apache.http.util.EntityUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import java.io.IOException;
+
+/**
+ * An adapter to communicate with information micro-service.
+ */
+@Component
+public class ProductInformationClientImpl implements ProductInformationClient {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(ProductInformationClientImpl.class);
+
+  @Override
+  public String getProductTitle() {
+    String response = null;
+    try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
+      HttpGet httpGet = new HttpGet("http://localhost:51515/information");
+      try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) {
+        response = EntityUtils.toString(httpResponse.getEntity());
+      }
+    } catch (IOException e) {
+      LOGGER.error("Exception caught.", e);
+    }
+    return response;
+  }
+}

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

@@ -0,0 +1,31 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.aggregator.microservices;
+
+/**
+ * Interface to Inventory micro-service.
+ */
+public interface ProductInventoryClient {
+
+  int getProductInventories();
+}

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

@@ -0,0 +1,57 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.aggregator.microservices;
+
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClients;
+import org.apache.http.util.EntityUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.stereotype.Component;
+
+import java.io.IOException;
+
+/**
+ * An adapter to communicate with inventory micro-service.
+ */
+@Component
+public class ProductInventoryClientImpl implements ProductInventoryClient {
+
+  private static final Logger LOGGER = LoggerFactory.getLogger(ProductInventoryClientImpl.class);
+
+  @Override
+  public int getProductInventories() {
+    String response = "0";
+    try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
+      HttpGet httpGet = new HttpGet("http://localhost:51516/inventories");
+      try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) {
+        response = EntityUtils.toString(httpResponse.getEntity());
+      }
+    } catch (IOException e) {
+      LOGGER.error("Exception caught.", e);
+    }
+    return Integer.parseInt(response);
+  }
+}

aggregator-microservices/aggregator-service/src/main/resources/application.properties

@@ -0,0 +1,24 @@
+#
+# The MIT License
+# Copyright (c) 2014-2016 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.
+#
+
+server.port=50004

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

@@ -0,0 +1,70 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.aggregator.microservices;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.when;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+/**
+ * Test Aggregation of domain objects
+ */
+public class AggregatorTest {
+
+  @InjectMocks
+  private Aggregator aggregator;
+
+  @Mock
+  private ProductInformationClient informationClient;
+
+  @Mock
+  private ProductInventoryClient inventoryClient;
+
+  @Before
+  public void setup() {
+    MockitoAnnotations.initMocks(this);
+  }
+
+  /**
+   * Tests getting the data for a desktop client
+   */
+  @Test
+  public void testGetProduct() {
+    String title = "The Product Title.";
+    int inventories = 5;
+
+    when(informationClient.getProductTitle()).thenReturn(title);
+    when(inventoryClient.getProductInventories()).thenReturn(inventories);
+
+    Product testProduct = aggregator.getProduct();
+
+    assertEquals(title, testProduct.getTitle());
+    assertEquals(inventories, testProduct.getProductInventories());
+  }
+
+}

aggregator-microservices/etc/aggregator-service.urm.puml

@@ -0,0 +1,43 @@
+@startuml
+package com.iluwatar.aggregator.microservices {
+  class Aggregator {
+    - informationClient : ProductInformationClient
+    - inventoryClient : ProductInventoryClient
+    + Aggregator()
+    + getProduct() : Product
+  }
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  class Product {
+    - productInventories : int
+    - title : String
+    + Product()
+    + getProductInventories() : int
+    + getTitle() : String
+    + setProductInventories(productInventories : int)
+    + setTitle(title : String)
+  }
+  interface ProductInformationClient {
+    + getProductTitle() : String {abstract}
+  }
+  class ProductInformationClientImpl {
+    - LOGGER : Logger {static}
+    + ProductInformationClientImpl()
+    + getProductTitle() : String
+  }
+  interface ProductInventoryClient {
+    + getProductInventories() : int {abstract}
+  }
+  class ProductInventoryClientImpl {
+    - LOGGER : Logger {static}
+    + ProductInventoryClientImpl()
+    + getProductInventories() : int
+  }
+}
+Aggregator -->  "-informationClient" ProductInformationClient
+Aggregator -->  "-inventoryClient" ProductInventoryClient
+ProductInformationClientImpl ..|> ProductInformationClient 
+ProductInventoryClientImpl ..|> ProductInventoryClient 
+@enduml

aggregator-microservices/etc/information-microservice.urm.puml

@@ -0,0 +1,12 @@
+@startuml
+package com.iluwatar.information.microservice {
+  class InformationApplication {
+    + InformationApplication()
+    + main(args : String[]) {static}
+  }
+  class InformationController {
+    + InformationController()
+    + getProductTitle() : String
+  }
+}
+@enduml

aggregator-microservices/etc/inventory-microservice.urm.puml

@@ -0,0 +1,12 @@
+@startuml
+package com.iluwatar.inventory.microservice {
+  class InventoryApplication {
+    + InventoryApplication()
+    + main(args : String[]) {static}
+  }
+  class InventoryController {
+    + InventoryController()
+    + getProductInventories() : int
+  }
+}
+@enduml

aggregator-microservices/information-microservice/pom.xml

@@ -0,0 +1,79 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    The MIT License
+    Copyright (c) 2014-2016 Ilkka Seppälä
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>aggregator-microservices</artifactId>
+        <groupId>com.iluwatar</groupId>
+        <version>1.17.0</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>information-microservice</artifactId>
+    <packaging>jar</packaging>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-webmvc</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <version>${spring-boot.version}</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>repackage</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+</project>

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

@@ -0,0 +1,37 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.information.microservice;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * Inventory Application starts container (Spring Boot) and exposes the Inventory micro-service.
+ */
+@SpringBootApplication
+public class InformationApplication {
+
+  public static void main(String[] args) {
+    SpringApplication.run(InformationApplication.class, args);
+  }
+}

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

@@ -0,0 +1,44 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.information.microservice;
+
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * Controller providing endpoints to retrieve information about products
+ */
+@RestController
+public class InformationController {
+
+  /**
+   * Endpoint to retrieve a product's informations.
+   *
+   * @return product inventory.
+   */
+  @RequestMapping(value = "/information", method = RequestMethod.GET)
+  public String getProductTitle() {
+    return "The Product Title.";
+  }
+}

aggregator-microservices/information-microservice/src/main/resources/application.properties

@@ -0,0 +1,24 @@
+#
+# The MIT License
+# Copyright (c) 2014-2016 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.
+#
+
+server.port=51515

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

@@ -0,0 +1,42 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.information.microservice;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Test for Information Rest Controller
+ */
+public class InformationControllerTest {
+
+  @Test
+  public void shouldGetProductTitle() {
+    InformationController infoController = new InformationController();
+
+    String title = infoController.getProductTitle();
+
+    Assert.assertEquals("The Product Title.", title);
+  }
+
+}

aggregator-microservices/inventory-microservice/pom.xml

@@ -0,0 +1,79 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    The MIT License
+    Copyright (c) 2014-2016 Ilkka Seppälä
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>aggregator-microservices</artifactId>
+        <groupId>com.iluwatar</groupId>
+        <version>1.17.0</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+
+    <artifactId>inventory-microservice</artifactId>
+    <packaging>jar</packaging>
+
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-webmvc</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <version>${spring-boot.version}</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>repackage</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+        </plugins>
+    </build>
+</project>

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

@@ -0,0 +1,38 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.inventory.microservice;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * Inventory Application starts container (Spring Boot) and exposes the Inventory micro-service.
+ */
+@SpringBootApplication
+public class InventoryApplication {
+
+  public static void main(String[] args) {
+    SpringApplication.run(InventoryApplication.class, args);
+  }
+
+}

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

@@ -0,0 +1,45 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.inventory.microservice;
+
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * Controller providing endpoints to retrieve product inventories
+ */
+@RestController
+public class InventoryController {
+
+  /**
+   * Endpoint to retrieve a product's inventories.
+   *
+   * @return product inventory.
+   */
+  @RequestMapping(value = "/inventories", method = RequestMethod.GET)
+  public int getProductInventories() {
+    return 5;
+  }
+
+}

aggregator-microservices/inventory-microservice/src/main/resources/application.properties

@@ -0,0 +1,24 @@
+#
+# The MIT License
+# Copyright (c) 2014-2016 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.
+#
+
+server.port=51516

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

@@ -0,0 +1,40 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 Ilkka Seppälä
+ * <p/>
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * <p/>
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * <p/>
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * 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.inventory.microservice;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Test Inventory Rest Controller
+ */
+public class InventoryControllerTest {
+  @Test
+  public void testGetProductInventories() throws Exception {
+    InventoryController inventoryController = new InventoryController();
+
+    int numberOfInventories = inventoryController.getProductInventories();
+
+    Assert.assertEquals(5, numberOfInventories);
+  }
+}

aggregator-microservices/pom.xml

@@ -0,0 +1,63 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    The MIT License
+    Copyright (c) 2014-2016 Ilkka Seppälä
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>java-design-patterns</artifactId>
+        <groupId>com.iluwatar</groupId>
+        <version>1.17.0</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>aggregator-microservices</artifactId>
+    <packaging>pom</packaging>
+
+    <build>
+		<plugins>
+            <plugin>
+                <groupId>com.github.markusmo3.urm</groupId>
+                <artifactId>urm-maven-plugin</artifactId>
+                <version>${urm.version}</version>
+                <configuration combine.self="override">
+                    <outputDirectory>${project.basedir}/../etc</outputDirectory>
+                    <packages>
+                        <param>com.iluwatar</param>
+                    </packages>
+                    <skipForProjects>
+                        <!-- skip for parent project -->
+                        <param>aggregator-microservices</param>
+                    </skipForProjects>
+                </configuration>
+            </plugin>
+		</plugins>
+	</build>
+
+    <modules>
+        <module>information-microservice</module>
+        <module>aggregator-service</module>
+        <module>inventory-microservice</module>
+    </modules>
+</project>

api-gateway/README.md

@@ -0,0 +1,31 @@
+---
+layout: pattern
+title: API Gateway
+folder: api-gateway
+permalink: /patterns/api-gateway/
+pumlid: JSox3SCm303HLP819FRUXg49cO542_nOyFPncUvUSszHwhbpMdyT4TCt0CDLcyIHdtGsEZLOez8vG7ek33JuueLbPvUcPM84cpeCz2S0fvI6mGjluA1_b-Tt2N5D6tNcw3y0
+categories: Architectural
+tags:
+- Java
+- Difficulty-Intermediate
+- Spring
+---
+
+## Intent
+
+Aggregate calls to microservices in a single location: the API Gateway. The user makes a single
+call to the API Gateway, and the API Gateway then calls each relevant microservice.
+
+![alt text](./etc/api-gateway.png "API Gateway")
+
+## Applicability
+
+Use the API Gateway pattern when
+
+* you're also using the Microservices pattern and need a single point of aggregation for your
+microservice calls
+
+## Credits
+
+* [microservices.io - API Gateway](http://microservices.io/patterns/apigateway.html)
+* [NGINX - Building Microservices: Using an API Gateway](https://www.nginx.com/blog/building-microservices-using-an-api-gateway/)

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

@@ -0,0 +1,87 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    The MIT License
+    Copyright (c) 2014-2016 Ilkka Seppälä
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <parent>
+    <artifactId>api-gateway</artifactId>
+    <groupId>com.iluwatar</groupId>
+    <version>1.17.0</version>
+  </parent>
+  <modelVersion>4.0.0</modelVersion>
+  <artifactId>api-gateway-service</artifactId>
+  <packaging>jar</packaging>
+
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-dependencies</artifactId>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
+  <dependencies>
+    <dependency>
+      <groupId>org.springframework</groupId>
+      <artifactId>spring-webmvc</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-web</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.httpcomponents</groupId>
+      <artifactId>httpclient</artifactId>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
+        <version>${spring-boot.version}</version>
+        <executions>
+          <execution>
+            <goals>
+              <goal>repackage</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>

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

@@ -0,0 +1,64 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 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.api.gateway;
+
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import javax.annotation.Resource;
+
+/**
+ * The ApiGateway aggregates calls to microservices based on the needs of the individual clients.
+ */
+@RestController
+public class ApiGateway {
+
+  @Resource
+  private ImageClient imageClient;
+
+  @Resource
+  private PriceClient priceClient;
+
+  /**
+   * Retrieves product information that desktop clients need
+   * @return Product information for clients on a desktop
+   */
+  @RequestMapping("/desktop")
+  public DesktopProduct getProductDesktop() {
+    DesktopProduct desktopProduct = new DesktopProduct();
+    desktopProduct.setImagePath(imageClient.getImagePath());
+    desktopProduct.setPrice(priceClient.getPrice());
+    return desktopProduct;
+  }
+
+  /**
+   * Retrieves product information that mobile clients need
+   * @return Product information for clients on a mobile device
+   */
+  @RequestMapping("/mobile")
+  public MobileProduct getProductMobile() {
+    MobileProduct mobileProduct = new MobileProduct();
+    mobileProduct.setPrice(priceClient.getPrice());
+    return mobileProduct;
+  }
+}

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

@@ -0,0 +1,66 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 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.api.gateway;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * With the Microservices pattern, a client may need data from multiple different microservices.
+ * If the client called each microservice directly, that could contribute to longer load times,
+ * since the client would have to make a network request for each microservice called. Moreover,
+ * having the client call each microservice directly ties the client to that microservice - if the
+ * internal implementations of the microservices change (for example, if two microservices are
+ * combined sometime in the future) or if the location (host and port) of a microservice changes,
+ * then every client that makes use of those microservices must be updated.
+ *
+ * <p>
+ * The intent of the API Gateway pattern is to alleviate some of these issues. In the API Gateway
+ * pattern, an additional entity (the API Gateway) is placed between the client and the
+ * microservices. The job of the API Gateway is to aggregate the calls to the microservices.
+ * Rather than the client calling each microservice individually, the client calls the API Gateway
+ * a single time. The API Gateway then calls each of the microservices that the client needs.
+ *
+ * <p>
+ * This implementation shows what the API Gateway pattern could look like for an e-commerce site.
+ * The {@link ApiGateway} makes calls to the Image and Price microservices using the
+ * {@link ImageClientImpl} and {@link PriceClientImpl} respectively. Customers viewing the site on a
+ * desktop device can see both price information and an image of a product, so the {@link ApiGateway}
+ * calls both of the microservices and aggregates the data in the {@link DesktopProduct} model.
+ * However, mobile users only see price information; they do not see a product image. For mobile
+ * users, the {@link ApiGateway} only retrieves price information, which it uses to populate the
+ * {@link MobileProduct}.
+ */
+@SpringBootApplication
+public class App {
+
+  /**
+   * Program entry point
+   *
+   * @param args
+   *          command line args
+   */
+  public static void main(String[] args) {
+    SpringApplication.run(App.class, args);
+  }
+}

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

@@ -0,0 +1,54 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 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.api.gateway;
+
+/**
+ * Encapsulates all of the information that a desktop client needs to display a product.
+ */
+public class DesktopProduct {
+  /**
+   * The price of the product
+   */
+  private String price;
+
+  /**
+   * The path to the image of the product
+   */
+  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/ImageClient.java

@@ -0,0 +1,30 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 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.api.gateway;
+
+/**
+ * An interface used to communicate with the Image microservice
+ */
+public interface ImageClient {
+  String getImagePath();
+}

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

@@ -0,0 +1,56 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 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.api.gateway;
+
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClients;
+import org.apache.http.util.EntityUtils;
+import org.springframework.stereotype.Component;
+
+import java.io.IOException;
+
+/**
+ * An adapter to communicate with the Image microservice
+ */
+@Component
+public class ImageClientImpl implements ImageClient {
+  /**
+   * Makes a simple HTTP Get request to the Image microservice
+   * @return The path to the image
+   */
+  @Override
+  public String getImagePath() {
+    String response = null;
+    try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
+      HttpGet httpGet = new HttpGet("http://localhost:50005/image-path");
+      try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) {
+        response = EntityUtils.toString(httpResponse.getEntity());
+      }
+    } catch (IOException e) {
+      e.printStackTrace();
+    }
+    return response;
+  }
+}

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

@@ -0,0 +1,41 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 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.api.gateway;
+
+/**
+ * Encapsulates all of the information that mobile client needs to display a product.
+ */
+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/PriceClient.java

@@ -0,0 +1,30 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 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.api.gateway;
+
+/**
+ * An interface used to communicate with the Price microservice
+ */
+public interface PriceClient {
+  String getPrice();
+}

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

@@ -0,0 +1,56 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 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.api.gateway;
+
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClients;
+import org.apache.http.util.EntityUtils;
+import org.springframework.stereotype.Component;
+
+import java.io.IOException;
+
+/**
+ * An adapter to communicate with the Price microservice
+ */
+@Component
+public class PriceClientImpl implements PriceClient {
+  /**
+   * Makes a simple HTTP Get request to the Price microservice
+   * @return The price of the product
+   */
+  @Override
+  public String getPrice() {
+    String response = null;
+    try (CloseableHttpClient httpClient = HttpClients.createDefault()) {
+      HttpGet httpGet = new HttpGet("http://localhost:50006/price");
+      try (CloseableHttpResponse httpResponse = httpClient.execute(httpGet)) {
+        response = EntityUtils.toString(httpResponse.getEntity());
+      }
+    } catch (IOException e) {
+      e.printStackTrace();
+    }
+    return response;
+  }
+}

api-gateway/api-gateway-service/src/main/resources/application.properties

@@ -0,0 +1,24 @@
+#
+# The MIT License
+# Copyright (c) 2014-2016 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.
+#
+
+server.port=50004

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

@@ -0,0 +1,81 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 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.api.gateway;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.Mockito.when;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+/**
+ * Test API Gateway Pattern
+ */
+public class ApiGatewayTest {
+
+  @InjectMocks
+  private ApiGateway apiGateway;
+
+  @Mock
+  private ImageClient imageClient;
+
+  @Mock
+  private PriceClient priceClient;
+
+  @Before
+  public void setup() {
+    MockitoAnnotations.initMocks(this);
+  }
+
+  /**
+   * Tests getting the data for a desktop client
+   */
+  @Test
+  public void testGetProductDesktop() {
+    String imagePath = "/product-image.png";
+    String price = "20";
+    when(imageClient.getImagePath()).thenReturn(imagePath);
+    when(priceClient.getPrice()).thenReturn(price);
+
+    DesktopProduct desktopProduct = apiGateway.getProductDesktop();
+
+    assertEquals(price, desktopProduct.getPrice());
+    assertEquals(imagePath, desktopProduct.getImagePath());
+  }
+
+  /**
+   * Tests getting the data for a mobile client
+   */
+  @Test
+  public void testGetProductMobile() {
+    String price = "20";
+    when(priceClient.getPrice()).thenReturn(price);
+
+    MobileProduct mobileProduct = apiGateway.getProductMobile();
+
+    assertEquals(price, mobileProduct.getPrice());
+  }
+}

api-gateway/etc/api-gateway-service.urm.puml

@@ -0,0 +1,48 @@
+@startuml
+package com.iluwatar.api.gateway {
+  class ApiGateway {
+    - imageClient : ImageClient
+    - priceClient : PriceClient
+    + ApiGateway()
+    + getProductDesktop() : DesktopProduct
+    + getProductMobile() : MobileProduct
+  }
+  class App {
+    + App()
+    + main(args : String[]) {static}
+  }
+  class DesktopProduct {
+    - imagePath : String
+    - price : String
+    + DesktopProduct()
+    + getImagePath() : String
+    + getPrice() : String
+    + setImagePath(imagePath : String)
+    + setPrice(price : String)
+  }
+  interface ImageClient {
+    + getImagePath() : String {abstract}
+  }
+  class ImageClientImpl {
+    + ImageClientImpl()
+    + getImagePath() : String
+  }
+  class MobileProduct {
+    - price : String
+    + MobileProduct()
+    + getPrice() : String
+    + setPrice(price : String)
+  }
+  interface PriceClient {
+    + getPrice() : String {abstract}
+  }
+  class PriceClientImpl {
+    + PriceClientImpl()
+    + getPrice() : String
+  }
+}
+ApiGateway -->  "-imageClient" ImageClient
+ApiGateway -->  "-priceClient" PriceClient
+ImageClientImpl ..|> ImageClient 
+PriceClientImpl ..|> PriceClient 
+@enduml

api-gateway/etc/api-gateway.ucls

@@ -1,105 +1,93 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<class-diagram version="1.1.8" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true" 
-  realizations="true" associations="true" dependencies="false" nesting-relationships="true">  
-  <class id="1" language="java" name="com.iluwatar.chain.Request" project="chain" 
-    file="/chain/src/main/java/com/iluwatar/chain/Request.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="196" width="228" x="168" y="182"/>    
+<class-diagram version="1.1.9" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true" 
+  realizations="true" associations="true" dependencies="false" nesting-relationships="true" router="FAN">  
+  <class id="1" language="java" name="com.iluwatar.api.gateway.ApiGateway" project="api-gateway" 
+    file="/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ApiGateway.java" binary="false" corner="BOTTOM_RIGHT">
+    <position height="-1" width="-1" x="125" y="87"/>    
     <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
       sort-features="false" accessors="true" visibility="true">      
       <attributes public="true" package="true" protected="true" private="true" static="true"/>      
       <operations public="true" package="true" protected="true" private="true" static="true"/>    
     </display>  
   </class>  
-  <class id="2" language="java" name="com.iluwatar.chain.OrcOfficer" project="chain" 
-    file="/chain/src/main/java/com/iluwatar/chain/OrcOfficer.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="124" width="194" x="168" y="609"/>    
+  <class id="2" language="java" name="com.iluwatar.api.gateway.DesktopProduct" project="api-gateway" 
+    file="/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/DesktopProduct.java" binary="false" corner="BOTTOM_RIGHT">
+    <position height="-1" width="-1" x="388" y="109"/>    
     <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
       sort-features="false" accessors="true" visibility="true">      
       <attributes public="true" package="true" protected="true" private="true" static="true"/>      
       <operations public="true" package="true" protected="true" private="true" static="true"/>    
     </display>  
   </class>  
-  <class id="3" language="java" name="com.iluwatar.chain.OrcCommander" project="chain" 
-    file="/chain/src/main/java/com/iluwatar/chain/OrcCommander.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="124" width="217" x="402" y="609"/>    
+  <interface id="3" language="java" name="com.iluwatar.api.gateway.ImageClient" project="api-gateway" 
+    file="/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ImageClient.java" binary="false" corner="BOTTOM_RIGHT">
+    <position height="81" width="129" x="13" y="197"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <class id="4" language="java" name="com.iluwatar.api.gateway.ImageClientImpl" project="api-gateway" 
+    file="/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/ImageClientImpl.java" binary="false" corner="BOTTOM_RIGHT">
+    <position height="99" width="129" x="13" y="325"/>    
     <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
       sort-features="false" accessors="true" visibility="true">      
       <attributes public="true" package="true" protected="true" private="true" static="true"/>      
       <operations public="true" package="true" protected="true" private="true" static="true"/>    
     </display>  
   </class>  
-  <class id="4" language="java" name="com.iluwatar.chain.RequestHandler" project="chain" 
-    file="/chain/src/main/java/com/iluwatar/chain/RequestHandler.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="141" width="218" x="451" y="418"/>    
+  <class id="5" language="java" name="com.iluwatar.api.gateway.MobileProduct" project="api-gateway" 
+    file="/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/MobileProduct.java" binary="false" corner="BOTTOM_RIGHT">
+    <position height="-1" width="-1" x="376" y="293"/>    
     <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
       sort-features="false" accessors="true" visibility="true">      
       <attributes public="true" package="true" protected="true" private="true" static="true"/>      
       <operations public="true" package="true" protected="true" private="true" static="true"/>    
     </display>  
   </class>  
-  <class id="5" language="java" name="com.iluwatar.chain.OrcSoldier" project="chain" 
-    file="/chain/src/main/java/com/iluwatar/chain/OrcSoldier.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="124" width="194" x="659" y="609"/>    
+  <interface id="6" language="java" name="com.iluwatar.api.gateway.PriceClient" project="api-gateway" 
+    file="/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/PriceClient.java" binary="false" corner="BOTTOM_RIGHT">
+    <position height="-1" width="-1" x="222" y="231"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </interface>  
+  <class id="7" language="java" name="com.iluwatar.api.gateway.PriceClientImpl" project="api-gateway" 
+    file="/api-gateway/api-gateway-service/src/main/java/com/iluwatar/api/gateway/PriceClientImpl.java" binary="false" corner="BOTTOM_RIGHT">
+    <position height="-1" width="-1" x="223" y="374"/>    
     <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
       sort-features="false" accessors="true" visibility="true">      
       <attributes public="true" package="true" protected="true" private="true" static="true"/>      
       <operations public="true" package="true" protected="true" private="true" static="true"/>    
     </display>  
   </class>  
-  <class id="6" language="java" name="com.iluwatar.chain.OrcKing" project="chain" 
-    file="/chain/src/main/java/com/iluwatar/chain/OrcKing.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="124" width="188" x="451" y="182"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </class>  
-  <enumeration id="7" language="java" name="com.iluwatar.chain.RequestType" project="chain" 
-    file="/chain/src/main/java/com/iluwatar/chain/RequestType.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="142" width="243" x="168" y="418"/>    
-    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
-      sort-features="false" accessors="true" visibility="true">      
-      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
-      <operations public="true" package="true" protected="true" private="true" static="true"/>    
-    </display>  
-  </enumeration>  
   <association id="8">    
-    <end type="SOURCE" refId="6" navigable="false">      
-      <attribute id="9" name="chain"/>      
+    <end type="SOURCE" refId="1" navigable="false">      
+      <attribute id="9" name="imageClient"/>      
       <multiplicity id="10" minimum="0" maximum="1"/>    
     </end>    
-    <end type="TARGET" refId="4" navigable="true"/>    
+    <end type="TARGET" refId="3" navigable="true"/>    
     <display labels="true" multiplicity="true"/>  
   </association>  
-  <association id="11">    
-    <end type="SOURCE" refId="4" navigable="false">      
-      <attribute id="12" name="next"/>      
-      <multiplicity id="13" minimum="0" maximum="1"/>    
-    </end>    
-    <end type="TARGET" refId="4" navigable="true"/>    
-    <display labels="true" multiplicity="true"/>  
-  </association>  
-  <generalization id="14">    
-    <end type="SOURCE" refId="5"/>    
-    <end type="TARGET" refId="4"/>  
-  </generalization>  
-  <association id="15">    
+  <realization id="11">    
+    <end type="SOURCE" refId="4"/>    
+    <end type="TARGET" refId="3"/>  
+  </realization>  
+  <association id="12">    
     <end type="SOURCE" refId="1" navigable="false">      
-      <attribute id="16" name="requestType"/>      
-      <multiplicity id="17" minimum="0" maximum="1"/>    
+      <attribute id="13" name="priceClient"/>      
+      <multiplicity id="14" minimum="0" maximum="1"/>    
     </end>    
-    <end type="TARGET" refId="7" navigable="true"/>    
+    <end type="TARGET" refId="6" navigable="true"/>    
     <display labels="true" multiplicity="true"/>  
   </association>  
-  <generalization id="18">    
-    <end type="SOURCE" refId="2"/>    
-    <end type="TARGET" refId="4"/>  
-  </generalization>  
-  <generalization id="19">    
-    <end type="SOURCE" refId="3"/>    
-    <end type="TARGET" refId="4"/>  
-  </generalization>  
+  <realization id="15">    
+    <end type="SOURCE" refId="7"/>    
+    <end type="TARGET" refId="6"/>  
+  </realization>  
   <classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
     sort-features="false" accessors="true" visibility="true">    
     <attributes public="true" package="true" protected="true" private="true" static="true"/>    

api-gateway/etc/image-microservice.urm.puml

@@ -0,0 +1,12 @@
+@startuml
+package com.iluwatar.image.microservice {
+  class ImageApplication {
+    + ImageApplication()
+    + main(args : String[]) {static}
+  }
+  class ImageController {
+    + ImageController()
+    + getImagePath() : String
+  }
+}
+@enduml

api-gateway/etc/price-microservice.urm.puml

@@ -0,0 +1,12 @@
+@startuml
+package com.iluwatar.price.microservice {
+  class PriceApplication {
+    + PriceApplication()
+    + main(args : String[]) {static}
+  }
+  class PriceController {
+    + PriceController()
+    + getPrice() : String
+  }
+}
+@enduml

api-gateway/image-microservice/etc/image-microservice.ucls

@@ -0,0 +1,20 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<class-diagram version="1.1.9" icons="true" automaticImage="PNG" always-add-relationships="false" generalizations="true" 
+  realizations="true" associations="true" dependencies="false" nesting-relationships="true" router="FAN">  
+  <class id="1" language="java" name="com.iluwatar.image.microservice.ImageController" project="image-microservice" 
+    file="/image-microservice/src/main/java/com/iluwatar/image/microservice/ImageController.java" binary="false" 
+    corner="BOTTOM_RIGHT">    
+    <position height="-1" width="-1" x="87" y="61"/>    
+    <display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+      sort-features="false" accessors="true" visibility="true">      
+      <attributes public="true" package="true" protected="true" private="true" static="true"/>      
+      <operations public="true" package="true" protected="true" private="true" static="true"/>    
+    </display>  
+  </class>  
+  <classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="true" 
+    sort-features="false" accessors="true" visibility="true">    
+    <attributes public="true" package="true" protected="true" private="true" static="true"/>    
+    <operations public="true" package="true" protected="true" private="true" static="true"/>  
+  </classifier-display>  
+  <association-display labels="true" multiplicity="true"/>
+</class-diagram>

api-gateway/image-microservice/pom.xml

@@ -0,0 +1,79 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+
+    The MIT License
+    Copyright (c) 2014-2016 Ilkka Seppälä
+
+    Permission is hereby granted, free of charge, to any person obtaining a copy
+    of this software and associated documentation files (the "Software"), to deal
+    in the Software without restriction, including without limitation the rights
+    to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+    copies of the Software, and to permit persons to whom the Software is
+    furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included in
+    all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+    AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+    OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+    THE SOFTWARE.
+
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <parent>
+    <artifactId>api-gateway</artifactId>
+    <groupId>com.iluwatar</groupId>
+    <version>1.17.0</version>
+  </parent>
+
+  <modelVersion>4.0.0</modelVersion>
+  <artifactId>image-microservice</artifactId>
+  <packaging>jar</packaging>
+
+  <dependencyManagement>
+    <dependencies>
+      <dependency>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-dependencies</artifactId>
+      </dependency>
+    </dependencies>
+  </dependencyManagement>
+  <dependencies>
+    <dependency>
+      <groupId>org.springframework</groupId>
+      <artifactId>spring-webmvc</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-web</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
+        <version>${spring-boot.version}</version>
+        <executions>
+          <execution>
+            <goals>
+              <goal>repackage</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+</project>

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

@@ -0,0 +1,43 @@
+/**
+ * The MIT License
+ * Copyright (c) 2014-2016 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.image.microservice;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+/**
+ * ImageApplication starts up Spring Boot, exposing endpoints for the Image microservice through
+ * the {@link ImageController}.
+ */
+@SpringBootApplication
+public class ImageApplication {
+
+  /**
+   * Microservice entry point
+   * @param args
+   *          command line args
+   */
+  public static void main(String[] args) {
+    SpringApplication.run(ImageApplication.class, args);
+  }
+}