Move urm plugin configuration to parent pom.xml

.travis.yml

@@ -1,18 +1,20 @@
 language: java
+
 jdk:
   - oraclejdk8
 
 env:
   global:
   - GH_REF: github.com/iluwatar/java-design-patterns.git
-  - secure: LxTDuNS/rBWIvKkaEqr79ImZAe48mCdoYCF41coxNXgNoippo4GIBArknqtv+XvdkiuRZ1yGyj6pn8GU33c/yn+krddTUkVCwTbVatbalW5jhQjDbHYym/JcxaK9ZS/3JTeGcWrBgiPqHEEDhCf26vPZsXoMSeVCEORVKTp1BSg=
+  - secure: "LxTDuNS/rBWIvKkaEqr79ImZAe48mCdoYCF41coxNXgNoippo4GIBArknqtv+XvdkiuRZ1yGyj6pn8GU33c/yn+krddTUkVCwTbVatbalW5jhQjDbHYym/JcxaK9ZS/3JTeGcWrBgiPqHEEDhCf26vPZsXoMSeVCEORVKTp1BSg="
 
 before_install:
-- export DISPLAY=:99.0
-- sh -e /etc/init.d/xvfb start
+  - "export DISPLAY=:99.0"
+  - "sh -e /etc/init.d/xvfb start"
   
 after_success:
   - mvn clean test jacoco:report coveralls:report
   - bash update-ghpages.sh
 
+# Migration to container-based infrastructure  
 sudo: false

CODE_COVERAGE.md

@@ -1,13 +0,0 @@
-# Code Coverage Report generation
-
-To generate the code coverage report, execute the following command:
-> mvn clean verify
-
-This will generate code coverage report in each of the modules. In order to view the same, open the following file in your browser.
-> target/site/jacoco/index.html 
-
-Please note that the above folder is created under each of the modules. For example:
-* adapter/target/site/jacoco/index.html 
-* busniess-delegate/target/site/jacoco/index.html 
-
-

CONTRIBUTING.MD

@@ -1,4 +0,0 @@
-This is great you have something to contribute! 
-
-Before going any further please read the [wiki](https://github.com/iluwatar/java-design-patterns/wiki)
-with conventions and rules we used for this project.

README.md

@@ -2,10 +2,11 @@
      that smart and dearly wants an empty line before a heading to be able to
      display it as such, e.g. website) -->
 
-# Design patterns implemented in Java
+# Design pattern samples 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)
+[![Coverity Scan Build Status](https://scan.coverity.com/projects/5634/badge.svg)](https://scan.coverity.com/projects/5634)
 [![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)
 
 # Introduction
@@ -25,13 +26,7 @@ are familiar with the patterns.
 Before you dive into the material, you should be familiar with various 
 [Programming/Software Design Principles](http://webpro.github.io/programming-principles/). 
 
-All designs should be as simple as possible. You should start with KISS, YAGNI,
-and Do The Simplest Thing That Could Possibly Work principles. Complexity and
-patterns should only be introduced when they are needed for practical
-extensibility.
-
-Once you are familiar with these concepts you can start drilling down into
-patterns by any of the following approaches
+Once you are familiar with these concepts you can start drilling down into patterns by any of the following approaches
 
  - Using difficulty tags, `Difficulty-Beginner`, `Difficulty-Intermediate` & `Difficulty-Expert`.
  - Using pattern categories, `Creational`, `Behavioral` and others.
@@ -39,10 +34,11 @@ patterns by any of the following approaches
 
 # How to contribute
 
-If you are willing to contribute to the project you will find the relevant information in our [developer wiki](https://github.com/iluwatar/java-design-patterns/wiki). We will help you and answer your questions in the [Gitter chatroom](https://gitter.im/iluwatar/java-design-patterns).
+If you are willing to contribute to the project you will find the relevant information in our [developer wiki](https://github.com/iluwatar/java-design-patterns/wiki).
 
 # Credits
 
+* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)
 * [Effective Java (2nd Edition)](http://www.amazon.com/Effective-Java-Edition-Joshua-Bloch/dp/0321356683)
 * [Java Generics and Collections](http://www.amazon.com/Java-Generics-Collections-Maurice-Naftalin/dp/0596527756/)
 * [Let's Modify the Objects-First Approach into Design-Patterns-First](http://edu.pecinovsky.cz/papers/2006_ITiCSE_Design_Patterns_First.pdf)
@@ -52,6 +48,7 @@ If you are willing to contribute to the project you will find the relevant infor
 * [Patterns of Enterprise Application Architecture](http://www.amazon.com/Patterns-Enterprise-Application-Architecture-Martin/dp/0321127420)
 * [Spring Data](http://www.amazon.com/Spring-Data-Mark-Pollack/dp/1449323952/ref=sr_1_1)
 * [J2EE Design Patterns](http://www.amazon.com/J2EE-Design-Patterns-William-Crawford/dp/0596004273/ref=sr_1_2)
+* [Pattern Oriented Software Architecture Vol I-V](http://www.amazon.com/Pattern-Oriented-Software-Architecture-Volume-Patterns/dp/0471958697)
 
 # License
 

abstract-factory/index.md

@@ -4,14 +4,9 @@ title: Abstract Factory
 folder: abstract-factory
 permalink: /patterns/abstract-factory/
 categories: Creational
-tags: 
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+tags: Java
 ---
 
-**Also known as:** Kit
-
 **Intent:** Provide an interface for creating families of related or dependent
 objects without specifying their concrete classes.
 
@@ -27,7 +22,3 @@ objects without specifying their concrete classes.
 **Real world examples:**
 
 * [javax.xml.parsers.DocumentBuilderFactory](http://docs.oracle.com/javase/8/docs/api/javax/xml/parsers/DocumentBuilderFactory.html)
-
-**Credits**
-
-* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)

abstract-factory/pom.xml

@@ -1,11 +1,12 @@
 <?xml version="1.0"?>
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-    <version>1.9.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>abstract-factory</artifactId>
 	<dependencies>

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

@@ -1,18 +1,14 @@
 package com.iluwatar.abstractfactory;
 
+
 /**
  * 
- * The Abstract Factory pattern provides a way to encapsulate a group of individual factories that have a common theme
- * without specifying their concrete classes. In normal usage, the client software creates a concrete implementation of
- * the abstract factory and then uses the generic interface of the factory to create the concrete objects that are part
- * of the theme. The client does not know (or care) which concrete objects it gets from each of these internal
- * factories, since it uses only the generic interfaces of their products. This pattern separates the details of
- * implementation of a set of objects from their general usage and relies on object composition, as object creation is
- * implemented in methods exposed in the factory interface.
+ * The essence of the Abstract Factory pattern is a factory interface
+ * ({@link KingdomFactory}) and its implementations ({@link ElfKingdomFactory},
+ * {@link OrcKingdomFactory}).
  * <p>
- * The essence of the Abstract Factory pattern is a factory interface ({@link KingdomFactory}) and its implementations (
- * {@link ElfKingdomFactory}, {@link OrcKingdomFactory}). The example uses both concrete implementations to create a
- * king, a castle and an army.
+ * The example uses both concrete implementations to create a king, a castle and
+ * an army.
  * 
  */
 public class App {
@@ -23,6 +19,7 @@ public class App {
 
 	/**
 	 * Creates kingdom
+	 * @param factory
 	 */
 	public void createKingdom(final KingdomFactory factory) {
 		setKing(factory.createKing());
@@ -42,6 +39,14 @@ public class App {
 		return factory.createKing();
 	}
 	
+	Castle getCastle(final KingdomFactory factory) {
+		return factory.createCastle();
+	}
+	
+	Army getArmy(final KingdomFactory factory) {
+		return factory.createArmy();
+	}
+	
 	public King getKing() {
 		return king;
 	}
@@ -50,10 +55,6 @@ public class App {
 		this.king = king;
 	}
 	
-  Castle getCastle(final KingdomFactory factory) {
-    return factory.createCastle();
-  }
-
 	public Castle getCastle() {
 		return castle;
 	}
@@ -62,10 +63,6 @@ public class App {
 		this.castle = castle;
 	}
 	
-  Army getArmy(final KingdomFactory factory) {
-    return factory.createArmy();
-  }
-
 	public Army getArmy() {
 		return army;
 	}
@@ -73,33 +70,4 @@ public class App {
 	private void setArmy(final Army army) {
 		this.army = army;
 	}
-  
-  /**
-   * Program entry point
-   * 
-   * @param args
-   *          command line args
-   */
-  public static void main(String[] args) {
-
-    App app = new App();
-
-    System.out.println("Elf Kingdom");
-    KingdomFactory elfKingdomFactory;
-    elfKingdomFactory = app.getElfKingdomFactory();
-    app.createKingdom(elfKingdomFactory);
-    System.out.println(app.getArmy().getDescription());
-    System.out.println(app.getCastle().getDescription());
-    System.out.println(app.getKing().getDescription());
-
-    System.out.println("\nOrc Kingdom");
-    KingdomFactory orcKingdomFactory;
-    orcKingdomFactory = app.getOrcKingdomFactory();
-    app.createKingdom(orcKingdomFactory);
-    System.out.println(app.getArmy().getDescription());
-    System.out.println(app.getCastle().getDescription());
-    System.out.println(app.getKing().getDescription());
-
-  }
-
 }

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

@@ -18,4 +18,5 @@ public class OrcKingdomFactory implements KingdomFactory {
 	public Army createArmy() {
 		return new OrcArmy();
 	}
+
 }

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

@@ -1,5 +1,4 @@
 package com.iluwatar.abstractfactory;
-
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 
@@ -8,7 +7,7 @@ import org.junit.Test;
 
 public class AppTest {
 
-  private App app = new App();
+	private App app = new App();;
 	private KingdomFactory elfFactory;
 	private KingdomFactory orcFactory;
 	

adapter/etc/adapter.ucls

@@ -1,61 +1,61 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<class-diagram version="1.1.9" icons="true" always-add-relationships="false" generalizations="true" realizations="true" 
-  associations="true" dependencies="false" nesting-relationships="true" router="FAN">  
-  <class id="1" language="java" name="com.iluwatar.adapter.FishingBoat" project="adapter" 
-    file="/adapter/src/main/java/com/iluwatar/adapter/FishingBoat.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="656" y="355"/>    
+<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.adapter.GnomeEngineeringManager" project="adapter" 
+    file="/adapter/src/main/java/com/iluwatar/adapter/GnomeEngineeringManager.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="106" width="224" x="110" y="210"/>    
     <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.adapter.Captain" project="adapter" 
-    file="/adapter/src/main/java/com/iluwatar/adapter/Captain.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="228" y="185"/>    
-    <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.adapter.BattleFishingBoat" project="adapter" 
-    file="/adapter/src/main/java/com/iluwatar/adapter/BattleFishingBoat.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="463" y="357"/>    
-    <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="4" language="java" name="com.iluwatar.adapter.BattleShip" project="adapter" 
-    file="/adapter/src/main/java/com/iluwatar/adapter/BattleShip.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="466" y="170"/>    
+  <interface id="2" language="java" name="com.iluwatar.adapter.Engineer" project="adapter" 
+    file="/adapter/src/main/java/com/iluwatar/adapter/Engineer.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="88" width="141" x="110" y="356"/>    
     <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.adapter.GnomeEngineer" project="adapter" 
+    file="/adapter/src/main/java/com/iluwatar/adapter/GnomeEngineer.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="106" width="141" x="374" y="210"/>    
+    <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.adapter.GoblinGlider" project="adapter" 
+    file="/adapter/src/main/java/com/iluwatar/adapter/GoblinGlider.java" binary="false" corner="BOTTOM_RIGHT">    
+    <position height="142" width="130" x="374" y="356"/>    
+    <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="5">    
-    <end type="SOURCE" refId="2"/>    
-    <end type="TARGET" refId="4"/>  
+    <end type="SOURCE" refId="1"/>    
+    <end type="TARGET" refId="2"/>  
   </realization>  
-  <association id="6">    
-    <end type="SOURCE" refId="3" navigable="false">      
-      <attribute id="7" name="boat"/>      
-      <multiplicity id="8" minimum="0" maximum="1"/>    
+  <realization id="6">    
+    <end type="SOURCE" refId="3"/>    
+    <end type="TARGET" refId="2"/>  
+  </realization>  
+  <association id="7">    
+    <end type="SOURCE" refId="1" navigable="false">      
+      <attribute id="8" name="engineer"/>      
+      <multiplicity id="9" minimum="0" maximum="1"/>    
     </end>    
-    <end type="TARGET" refId="1" navigable="true"/>    
+    <end type="TARGET" refId="2" navigable="true"/>    
     <display labels="true" multiplicity="true"/>  
   </association>  
-  <realization id="9">    
-    <end type="SOURCE" refId="3"/>    
-    <end type="TARGET" refId="4"/>  
-  </realization>  
   <association id="10">    
-    <end type="SOURCE" refId="2" navigable="false">      
-      <attribute id="11" name="battleship"/>      
+    <end type="SOURCE" refId="3" navigable="false">      
+      <attribute id="11" name="glider"/>      
       <multiplicity id="12" minimum="0" maximum="1"/>    
     </end>    
     <end type="TARGET" refId="4" navigable="true"/>    

adapter/index.md

@@ -4,19 +4,14 @@ title: Adapter
 folder: adapter
 permalink: /patterns/adapter/
 categories: Structural
-tags:
- - Java
- - Gang Of Four
- - Difficulty-Beginner
+tags: Java
 ---
 
-**Also known as:** Wrapper
-
 **Intent:** 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")
+![alt text](./etc/adapter_1.png "Adapter")
 
 **Applicability:** Use the Adapter pattern when
 
@@ -27,7 +22,3 @@ incompatible interfaces.
 **Real world examples:**
 
 * [java.util.Arrays#asList()](http://docs.oracle.com/javase/8/docs/api/java/util/Arrays.html#asList%28T...%29)
-
-**Credits**
-
-* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)

adapter/pom.xml

@@ -1,11 +1,12 @@
 <?xml version="1.0"?>
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-    <version>1.9.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>adapter</artifactId>
 	<dependencies>
@@ -14,10 +15,5 @@
 			<artifactId>junit</artifactId>
 			<scope>test</scope>
 		</dependency>
-    <dependency>
-      <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
-      <scope>test</scope>
-    </dependency>
 	</dependencies>
 </project>

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

@@ -1,38 +1,25 @@
 package com.iluwatar.adapter;
 
 /**
- * An adapter helps two incompatible interfaces to work together. This is the real world definition
- * for an adapter. Interfaces may be incompatible but the inner functionality should suit the need.
- * The Adapter design pattern allows otherwise incompatible classes to work together by converting
- * the interface of one class into an interface expected by the clients.
  * 
+ * There are two variations of the Adapter pattern: The class adapter implements
+ * the adaptee's interface whereas the object adapter uses composition to
+ * contain the adaptee in the adapter object. This example uses the object
+ * adapter approach.
  * <p>
- * There are two variations of the Adapter pattern: The class adapter implements the adaptee's
- * interface whereas the object adapter uses composition to contain the adaptee in the adapter
- * object. This example uses the object adapter approach.
- *
- * <p>
- * The Adapter ({@link BattleFishingBoat}) converts the interface of the adaptee class (
- * {@link FishingBoat}) into a suitable one expected by the client ( {@link BattleShip} ).
- *
- * <p>
- * The story of this implementation is this. <br>
- * Pirates are coming! we need a {@link BattleShip} to fight! We have a {@link FishingBoat} and our
- * captain. We have no time to make up a new ship! we need to reuse this {@link FishingBoat}. The
- * captain needs a battleship which can fire and move. The spec is in {@link BattleShip}. We will
- * use the Adapter pattern to reuse {@link FishingBoat}.
+ * The Adapter ({@link GnomeEngineer}) converts the interface of the target class
+ * ({@link GoblinGlider}) into a suitable one expected by the client
+ * ({@link GnomeEngineeringManager}).
  * 
  */
 public class App {
 
 	/**
-   * Program entry point.
-   *
+	 * Program entry point
 	 * @param args command line args
 	 */
 	public static void main(String[] args) {
-    Captain captain = new Captain(new BattleFishingBoat());
-    captain.move();
-    captain.fire();
+		Engineer manager = new GnomeEngineeringManager();
+		manager.operateDevice();
 	}
 }

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

@@ -1,29 +0,0 @@
-package com.iluwatar.adapter;
-
-/**
- *
- * Adapter class. Adapts the interface of the device ({@link FishingBoat}) into {@link BattleShip}
- * interface expected by the client ({@link Captain}). <br>
- * In this case we added a new function fire to suit the interface. We are reusing the
- * {@link FishingBoat} without changing itself. The Adapter class can just map the functions of the
- * Adaptee or add, delete features of the Adaptee.
- *
- */
-public class BattleFishingBoat implements BattleShip {
-
-  private FishingBoat boat;
-
-  public BattleFishingBoat() {
-    boat = new FishingBoat();
-  }
-
-  @Override
-  public void fire() {
-    System.out.println("fire!");
-  }
-
-  @Override
-  public void move() {
-    boat.sail();
-  }
-}

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

@@ -1,14 +0,0 @@
-package com.iluwatar.adapter;
-
-/**
- * The interface expected by the client.<br>
- * A Battleship can fire and move.
- *
- */
-public interface BattleShip {
-
-  void fire();
-
-  void move();
-
-}

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

@@ -1,33 +0,0 @@
-package com.iluwatar.adapter;
-
-/**
- * The Captain uses {@link BattleShip} to fight. <br>
- * This is the client in the pattern.
- */
-public class Captain implements BattleShip {
-
-  private BattleShip battleship;
-
-  public Captain() {
-
-  }
-
-  public Captain(BattleShip battleship) {
-    this.battleship = battleship;
-  }
-
-  public void setBattleship(BattleShip battleship) {
-    this.battleship = battleship;
-  }
-
-  @Override
-  public void fire() {
-    battleship.fire();
-  }
-
-  @Override
-  public void move() {
-    battleship.move();
-  }
-
-}

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

@@ -0,0 +1,12 @@
+package com.iluwatar.adapter;
+
+/**
+ * 
+ * Engineers can operate devices.
+ * 
+ */
+public interface Engineer {
+
+	void operateDevice();
+
+}

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

@@ -1,18 +0,0 @@
-package com.iluwatar.adapter;
-
-/**
- *
- * Device class (adaptee in the pattern). We want to reuse this class
- *
- */
-public class FishingBoat {
-
-  public void sail() {
-    System.out.println("The Boat is moving to that place");
-  }
-
-  public void fish() {
-    System.out.println("fishing ...");
-  }
-
-}

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

@@ -0,0 +1,24 @@
+package com.iluwatar.adapter;
+
+/**
+ * 
+ * Adapter class. Adapts the interface of the device ({@link GoblinGlider}) into
+ * {@link Engineer} interface expected by the client ({@link GnomeEngineeringManager}).
+ * 
+ */
+public class GnomeEngineer implements Engineer {
+
+	private GoblinGlider glider;
+
+	public GnomeEngineer() {
+		glider = new GoblinGlider();
+	}
+
+	@Override
+	public void operateDevice() {
+		glider.attachGlider();
+		glider.gainSpeed();
+		glider.takeOff();
+	}
+
+}

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

@@ -0,0 +1,20 @@
+package com.iluwatar.adapter;
+
+/**
+ * 
+ * GnomeEngineering manager uses {@link Engineer} to operate devices.
+ * 
+ */
+public class GnomeEngineeringManager implements Engineer {
+
+	private Engineer engineer;
+
+	public GnomeEngineeringManager() {
+		engineer = new GnomeEngineer();
+	}
+
+	@Override
+	public void operateDevice() {
+		engineer.operateDevice();
+	}
+}

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

@@ -0,0 +1,21 @@
+package com.iluwatar.adapter;
+
+/**
+ * 
+ * Device class (adaptee in the pattern).
+ * 
+ */
+public class GoblinGlider {
+
+	public void attachGlider() {
+		System.out.println("Glider attached.");
+	}
+
+	public void gainSpeed() {
+		System.out.println("Gaining speed.");
+	}
+
+	public void takeOff() {
+		System.out.println("Lift-off!");
+	}
+}

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

@@ -1,61 +0,0 @@
-package com.iluwatar.adapter;
-
-import org.junit.Before;
-import org.junit.Test;
-
-import java.util.HashMap;
-import java.util.Map;
-
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.verify;
-
-/**
- * Test class
- * 
- */
-public class AdapterPatternTest {
-
-  private Map<String, Object> beans;
-
-  private static final String BATTLESHIP_BEAN = "engineer";
-
-  private static final String CAPTAIN_BEAN = "captain";
-
-  /**
-   * This method runs before the test execution and sets the bean objects in the beans Map.
-   */
-  @Before
-  public void setup() {
-    beans = new HashMap<>();
-
-    BattleFishingBoat battleFishingBoat = spy(new BattleFishingBoat());
-    beans.put(BATTLESHIP_BEAN, battleFishingBoat);
-
-    Captain captain = new Captain();
-    captain.setBattleship((BattleFishingBoat) beans.get(BATTLESHIP_BEAN));
-    beans.put(CAPTAIN_BEAN, captain);
-  }
-
-  /**
-   * This test asserts that when we use the move() method on a captain bean(client), it is
-   * internally calling move method on the battleship object. The Adapter ({@link BattleFishingBoat}
-   * ) converts the interface of the target class ( {@link FishingBoat}) into a suitable one
-   * expected by the client ({@link Captain} ).
-   */
-  @Test
-  public void testAdapter() {
-    BattleShip captain = (BattleShip) beans.get(CAPTAIN_BEAN);
-
-    // when captain moves
-    captain.move();
-
-    // 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();
-
-  }
-}

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

@@ -0,0 +1,19 @@
+package com.iluwatar.adapter;
+
+import org.junit.Test;
+
+import com.iluwatar.adapter.App;
+
+/**
+ * 
+ * Application test
+ *
+ */
+public class AppTest {
+
+	@Test
+	public void test() {
+		String[] args = {};
+		App.main(args);
+	}
+}

async-method-invocation/index.md

@@ -4,10 +4,7 @@ title: Async Method Invocation
 folder: async-method-invocation
 permalink: /patterns/async-method-invocation/
 categories: Concurrency
-tags:
- - Java
- - Difficulty-Intermediate
- - Functional
+tags: Java
 ---
 
 **Intent:** Asynchronous method invocation is pattern where the calling thread

async-method-invocation/pom.xml

@@ -1,11 +1,12 @@
 <?xml version="1.0"?>
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-    <version>1.9.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>async-method-invocation</artifactId>
 	<dependencies>
@@ -14,10 +15,5 @@
 			<artifactId>junit</artifactId>
 			<scope>test</scope>
 		</dependency>
-    <dependency>
-      <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
-      <scope>test</scope>
-    </dependency>
 	</dependencies>
 </project>

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

@@ -5,22 +5,22 @@ import java.util.concurrent.Callable;
 /**
  * This application demonstrates the async method invocation pattern. Key parts of the pattern are
  * <code>AsyncResult</code> which is an intermediate container for an asynchronously evaluated value,
- * <code>AsyncCallback</code> which can be provided to be executed on task completion and <code>AsyncExecutor</code>
- * that manages the execution of the async tasks.
+ * <code>AsyncCallback</code> which can be provided to be executed on task completion and
+ * <code>AsyncExecutor</code> that manages the execution of the async tasks.
  * <p>
- * The main method shows example flow of async invocations. The main thread starts multiple tasks with variable
- * durations and then continues its own work. When the main thread has done it's job it collects the results of the
- * async tasks. Two of the tasks are handled with callbacks, meaning the callbacks are executed immediately when the
- * tasks complete.
+ * The main method shows example flow of async invocations. The main thread starts multiple tasks with
+ * variable durations and then continues its own work. When the main thread has done it's job it collects
+ * the results of the async tasks. Two of the tasks are handled with callbacks, meaning the callbacks are
+ * executed immediately when the tasks complete.
  * <p>
- * Noteworthy difference of thread usage between the async results and callbacks is that the async results are collected
- * in the main thread but the callbacks are executed within the worker threads. This should be noted when working with
- * thread pools.
+ * Noteworthy difference of thread usage between the async results and callbacks is that the async results
+ * are collected in the main thread but the callbacks are executed within the worker threads. This should be
+ * noted when working with thread pools.
  * <p>
- * Java provides its own implementations of async method invocation pattern. FutureTask, CompletableFuture and
- * ExecutorService are the real world implementations of this pattern. But due to the nature of parallel programming,
- * the implementations are not trivial. This example does not take all possible scenarios into account but rather
- * provides a simple version that helps to understand the pattern.
+ * Java provides its own implementations of async method invocation pattern. FutureTask, CompletableFuture
+ * and ExecutorService are the real world implementations of this pattern. But due to the nature of parallel
+ * programming, the implementations are not trivial. This example does not take all possible scenarios into
+ * account but rather provides a simple version that helps to understand the pattern.
  *
  * @see AsyncResult
  * @see AsyncCallback
@@ -32,9 +32,6 @@ import java.util.concurrent.Callable;
  */
 public class App {
 
-  /**
-   * Program entry point
-   */
 	public static void main(String[] args) throws Exception {
 		// construct a new executor that will run async tasks
 		AsyncExecutor executor = new ThreadAsyncExecutor();
@@ -66,10 +63,8 @@ public class App {
 	/**
 	 * Creates a callable that lazily evaluates to given value with artificial delay.
 	 *
-   * @param value
-   *          value to evaluate
-   * @param delayMillis
-   *          artificial delay in milliseconds
+	 * @param value value to evaluate
+	 * @param delayMillis artificial delay in milliseconds
 	 * @return new callable for lazy evaluation
 	 */
 	private static <T> Callable<T> lazyval(T value, long delayMillis) {
@@ -83,8 +78,7 @@ public class App {
 	/**
 	 * Creates a simple callback that logs the complete status of the async result.
 	 *
-   * @param name
-   *          callback name
+	 * @param name callback name
 	 * @return new async callback
 	 */
 	private static <T> AsyncCallback<T> callback(String name) {

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

@@ -18,4 +18,5 @@ public interface AsyncCallback<T> {
 	 * @param ex empty value if execution succeeds, some exception if executions fails
 	 */
 	void onComplete(T value, Optional<Exception> ex);
+
 }

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

@@ -38,4 +38,5 @@ public interface AsyncExecutor {
 	 * @throws InterruptedException if the execution is interrupted
 	 */
 	<T> T endProcess(AsyncResult<T> asyncResult) throws ExecutionException, InterruptedException;
+
 }

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

@@ -5,6 +5,8 @@ import java.util.concurrent.ExecutionException;
 /**
  * 
  * AsyncResult interface
+ *
+ * @param <T>
  */
 public interface AsyncResult<T> {
 

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

@@ -44,8 +44,9 @@ public class ThreadAsyncExecutor implements AsyncExecutor {
 	}
 
 	/**
-   * Simple implementation of async result that allows completing it successfully with a value or exceptionally with an
-   * exception. A really simplified version from its real life cousins FutureTask and CompletableFuture.
+	 * Simple implementation of async result that allows completing it successfully with a value
+	 * or exceptionally with an exception. A really simplified version from its real life cousins
+	 * FutureTask and CompletableFuture.
 	 *
 	 * @see java.util.concurrent.FutureTask
 	 * @see java.util.concurrent.CompletableFuture
@@ -69,11 +70,10 @@ public class ThreadAsyncExecutor implements AsyncExecutor {
 		}
 
 		/**
-     * Sets the value from successful execution and executes callback if available. Notifies any thread waiting for
-     * completion.
+		 * Sets the value from successful execution and executes callback if available. Notifies
+		 * any thread waiting for completion.
 		 *
-     * @param value
-     *          value of the evaluated task
+		 * @param value value of the evaluated task
 		 */
 		void setValue(T value) {
 			this.value = value;
@@ -85,11 +85,10 @@ public class ThreadAsyncExecutor implements AsyncExecutor {
 		}
 
 		/**
-     * Sets the exception from failed execution and executes callback if available. Notifies any thread waiting for
-     * completion.
+		 * Sets the exception from failed execution and executes callback if available. Notifies
+		 * any thread waiting for completion.
 		 *
-     * @param exception
-     *          exception of the failed task
+		 * @param exception exception of the failed task
 		 */
 		void setException(Exception exception) {
 			this.exception = exception;
@@ -102,7 +101,7 @@ public class ThreadAsyncExecutor implements AsyncExecutor {
 
 		@Override
 		public boolean isCompleted() {
-      return state > RUNNING;
+			return (state > RUNNING);
 		}
 
 		@Override

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

@@ -14,4 +14,5 @@ public class AppTest {
 		String[] args = {};
 		App.main(args);
 	}
+
 }

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

@@ -1,290 +0,0 @@
-package com.iluwatar.async.method.invocation;
-
-import org.junit.Test;
-import org.mockito.ArgumentCaptor;
-import org.mockito.Matchers;
-
-import java.util.Optional;
-import java.util.concurrent.Callable;
-import java.util.concurrent.ExecutionException;
-
-import static org.junit.Assert.*;
-import static org.mockito.Matchers.eq;
-import static org.mockito.Mockito.*;
-import static org.mockito.internal.verification.VerificationModeFactory.times;
-
-/**
- * Date: 12/6/15 - 10:49 AM
- *
- * @author Jeroen Meulemeester
- */
-public class ThreadAsyncExecutorTest {
-
-  /**
-   * Test used to verify the happy path of {@link ThreadAsyncExecutor#startProcess(Callable)}
-   */
-  @Test(timeout = 3000)
-  public void testSuccessfulTaskWithoutCallback() throws Exception {
-    // Instantiate a new executor and start a new 'null' task ...
-    final ThreadAsyncExecutor executor = new ThreadAsyncExecutor();
-
-    final Object result = new Object();
-    final Callable<Object> task = mock(Callable.class);
-    when(task.call()).thenReturn(result);
-
-    final AsyncResult<Object> asyncResult = executor.startProcess(task);
-    assertNotNull(asyncResult);
-    asyncResult.await(); // Prevent timing issues, and wait until the result is available
-    assertTrue(asyncResult.isCompleted());
-
-    // Our task should only execute once ...
-    verify(task, times(1)).call();
-
-    // ... and the result should be exactly the same object
-    assertSame(result, asyncResult.getValue());
-  }
-
-  /**
-   * Test used to verify the happy path of {@link ThreadAsyncExecutor#startProcess(Callable, AsyncCallback)}
-   */
-  @Test(timeout = 3000)
-  public void testSuccessfulTaskWithCallback() throws Exception {
-    // Instantiate a new executor and start a new 'null' task ...
-    final ThreadAsyncExecutor executor = new ThreadAsyncExecutor();
-
-    final Object result = new Object();
-    final Callable<Object> task = mock(Callable.class);
-    when(task.call()).thenReturn(result);
-
-    final AsyncCallback callback = mock(AsyncCallback.class);
-    final AsyncResult<Object> asyncResult = executor.startProcess(task, callback);
-    assertNotNull(asyncResult);
-    asyncResult.await(); // Prevent timing issues, and wait until the result is available
-    assertTrue(asyncResult.isCompleted());
-
-    // Our task should only execute once ...
-    verify(task, times(1)).call();
-
-    // ... same for the callback, we expect our object
-    final ArgumentCaptor<Optional<Exception>> optionalCaptor = ArgumentCaptor.forClass((Class) Optional.class);
-    verify(callback, times(1)).onComplete(eq(result), optionalCaptor.capture());
-
-    final Optional<Exception> optionalException = optionalCaptor.getValue();
-    assertNotNull(optionalException);
-    assertFalse(optionalException.isPresent());
-
-    // ... and the result should be exactly the same object
-    assertSame(result, asyncResult.getValue());
-  }
-
-  /**
-   * Test used to verify the happy path of {@link ThreadAsyncExecutor#startProcess(Callable)} when a task takes a while
-   * to execute
-   */
-  @Test(timeout = 5000)
-  public void testLongRunningTaskWithoutCallback() throws Exception {
-    // Instantiate a new executor and start a new 'null' task ...
-    final ThreadAsyncExecutor executor = new ThreadAsyncExecutor();
-
-    final Object result = new Object();
-    final Callable<Object> task = mock(Callable.class);
-    when(task.call()).thenAnswer(i -> {
-      Thread.sleep(1500);
-      return result;
-    });
-
-    final AsyncResult<Object> asyncResult = executor.startProcess(task);
-    assertNotNull(asyncResult);
-    assertFalse(asyncResult.isCompleted());
-
-    try {
-      asyncResult.getValue();
-      fail("Expected IllegalStateException when calling AsyncResult#getValue on a non-completed task");
-    } catch (IllegalStateException e) {
-      assertNotNull(e.getMessage());
-    }
-
-    // Our task should only execute once, but it can take a while ...
-    verify(task, timeout(3000).times(1)).call();
-
-    // Prevent timing issues, and wait until the result is available
-    asyncResult.await();
-    assertTrue(asyncResult.isCompleted());
-    verifyNoMoreInteractions(task);
-
-    // ... and the result should be exactly the same object
-    assertSame(result, asyncResult.getValue());
-  }
-
-  /**
-   * Test used to verify the happy path of {@link ThreadAsyncExecutor#startProcess(Callable, AsyncCallback)} when a task
-   * takes a while to execute
-   */
-  @Test(timeout = 5000)
-  public void testLongRunningTaskWithCallback() throws Exception {
-    // Instantiate a new executor and start a new 'null' task ...
-    final ThreadAsyncExecutor executor = new ThreadAsyncExecutor();
-
-    final Object result = new Object();
-    final Callable<Object> task = mock(Callable.class);
-    when(task.call()).thenAnswer(i -> {
-      Thread.sleep(1500);
-      return result;
-    });
-
-    final AsyncCallback<Object> callback = mock(AsyncCallback.class);
-    final AsyncResult<Object> asyncResult = executor.startProcess(task, callback);
-    assertNotNull(asyncResult);
-    assertFalse(asyncResult.isCompleted());
-
-    verifyZeroInteractions(callback);
-
-    try {
-      asyncResult.getValue();
-      fail("Expected IllegalStateException when calling AsyncResult#getValue on a non-completed task");
-    } catch (IllegalStateException e) {
-      assertNotNull(e.getMessage());
-    }
-
-    // Our task should only execute once, but it can take a while ...
-    verify(task, timeout(3000).times(1)).call();
-
-    final ArgumentCaptor<Optional<Exception>> optionalCaptor = ArgumentCaptor.forClass((Class) Optional.class);
-    verify(callback, timeout(3000).times(1)).onComplete(eq(result), optionalCaptor.capture());
-
-    final Optional<Exception> optionalException = optionalCaptor.getValue();
-    assertNotNull(optionalException);
-    assertFalse(optionalException.isPresent());
-
-    // Prevent timing issues, and wait until the result is available
-    asyncResult.await();
-    assertTrue(asyncResult.isCompleted());
-    verifyNoMoreInteractions(task, callback);
-
-    // ... and the result should be exactly the same object
-    assertSame(result, asyncResult.getValue());
-  }
-
-  /**
-   * Test used to verify the happy path of {@link ThreadAsyncExecutor#startProcess(Callable)} when a task takes a while
-   * to execute, while waiting on the result using {@link ThreadAsyncExecutor#endProcess(AsyncResult)}
-   */
-  @Test(timeout = 5000)
-  public void testEndProcess() throws Exception {
-    // Instantiate a new executor and start a new 'null' task ...
-    final ThreadAsyncExecutor executor = new ThreadAsyncExecutor();
-
-    final Object result = new Object();
-    final Callable<Object> task = mock(Callable.class);
-    when(task.call()).thenAnswer(i -> {
-      Thread.sleep(1500);
-      return result;
-    });
-
-    final AsyncResult<Object> asyncResult = executor.startProcess(task);
-    assertNotNull(asyncResult);
-    assertFalse(asyncResult.isCompleted());
-
-    try {
-      asyncResult.getValue();
-      fail("Expected IllegalStateException when calling AsyncResult#getValue on a non-completed task");
-    } catch (IllegalStateException e) {
-      assertNotNull(e.getMessage());
-    }
-
-    assertSame(result, executor.endProcess(asyncResult));
-    verify(task, times(1)).call();
-    assertTrue(asyncResult.isCompleted());
-
-    // Calling end process a second time while already finished should give the same result
-    assertSame(result, executor.endProcess(asyncResult));
-    verifyNoMoreInteractions(task);
-  }
-
-  /**
-   * Test used to verify the behaviour of {@link ThreadAsyncExecutor#startProcess(Callable)} when the callable is 'null'
-   */
-  @Test(timeout = 3000)
-  public void testNullTask() throws Exception {
-    // Instantiate a new executor and start a new 'null' task ...
-    final ThreadAsyncExecutor executor = new ThreadAsyncExecutor();
-    final AsyncResult<Object> asyncResult = executor.startProcess(null);
-
-    assertNotNull("The AsyncResult should not be 'null', even though the task was 'null'.", asyncResult);
-    asyncResult.await(); // Prevent timing issues, and wait until the result is available
-    assertTrue(asyncResult.isCompleted());
-
-    try {
-      asyncResult.getValue();
-      fail("Expected ExecutionException with NPE as cause");
-    } catch (final ExecutionException e) {
-      assertNotNull(e.getMessage());
-      assertNotNull(e.getCause());
-      assertEquals(NullPointerException.class, e.getCause().getClass());
-    }
-
-  }
-
-  /**
-   * Test used to verify the behaviour of {@link ThreadAsyncExecutor#startProcess(Callable, AsyncCallback)} when the
-   * callable is 'null', but the asynchronous callback is provided
-   */
-  @Test(timeout = 3000)
-  public void testNullTaskWithCallback() throws Exception {
-    // Instantiate a new executor and start a new 'null' task ...
-    final ThreadAsyncExecutor executor = new ThreadAsyncExecutor();
-    final AsyncCallback<Object> callback = mock(AsyncCallback.class);
-    final AsyncResult<Object> asyncResult = executor.startProcess(null, callback);
-
-    assertNotNull("The AsyncResult should not be 'null', even though the task was 'null'.", asyncResult);
-    asyncResult.await(); // Prevent timing issues, and wait until the result is available
-    assertTrue(asyncResult.isCompleted());
-
-    final ArgumentCaptor<Optional<Exception>> optionalCaptor = ArgumentCaptor.forClass((Class) Optional.class);
-    verify(callback, times(1)).onComplete(Matchers.isNull(), optionalCaptor.capture());
-
-    final Optional<Exception> optionalException = optionalCaptor.getValue();
-    assertNotNull(optionalException);
-    assertTrue(optionalException.isPresent());
-
-    final Exception exception = optionalException.get();
-    assertNotNull(exception);
-    assertEquals(NullPointerException.class, exception.getClass());
-
-    try {
-      asyncResult.getValue();
-      fail("Expected ExecutionException with NPE as cause");
-    } catch (final ExecutionException e) {
-      assertNotNull(e.getMessage());
-      assertNotNull(e.getCause());
-      assertEquals(NullPointerException.class, e.getCause().getClass());
-    }
-
-  }
-
-  /**
-   * Test used to verify the behaviour of {@link ThreadAsyncExecutor#startProcess(Callable, AsyncCallback)} when both
-   * the callable and the asynchronous callback are 'null'
-   */
-  @Test(timeout = 3000)
-  public void testNullTaskWithNullCallback() throws Exception {
-    // Instantiate a new executor and start a new 'null' task ...
-    final ThreadAsyncExecutor executor = new ThreadAsyncExecutor();
-    final AsyncResult<Object> asyncResult = executor.startProcess(null, null);
-
-    assertNotNull("The AsyncResult should not be 'null', even though the task and callback were 'null'.", asyncResult);
-    asyncResult.await(); // Prevent timing issues, and wait until the result is available
-    assertTrue(asyncResult.isCompleted());
-
-    try {
-      asyncResult.getValue();
-      fail("Expected ExecutionException with NPE as cause");
-    } catch (final ExecutionException e) {
-      assertNotNull(e.getMessage());
-      assertNotNull(e.getCause());
-      assertEquals(NullPointerException.class, e.getCause().getClass());
-    }
-
-  }
-
-}

bridge/index.md

@@ -4,14 +4,9 @@ title: Bridge
 folder: bridge
 permalink: /patterns/bridge/
 categories: Structural
-tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+tags: Java
 ---
 
-**Also known as:** Handle/Body
-
 **Intent:** Decouple an abstraction from its implementation so that the two can
 vary independently.
 
@@ -25,7 +20,3 @@ vary independently.
 * changes in the implementation of an abstraction should have no impact on clients; that is, their code should not have to be recompiled.
 * you have a proliferation of classes. Such a class hierarchy indicates the need for splitting an object into two parts. Rumbaugh uses the term "nested generalizations" to refer to such class hierarchies
 * you want to share an implementation among multiple objects (perhaps using reference counting), and this fact should be hidden from the client. A simple example is Coplien's String class, in which multiple objects can share the same string representation.
-
-**Credits**
-
-* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)

bridge/pom.xml

@@ -1,11 +1,12 @@
 <?xml version="1.0"?>
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-    <version>1.9.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>bridge</artifactId>
 	<dependencies>
@@ -14,10 +15,5 @@
 			<artifactId>junit</artifactId>
 			<scope>test</scope>
 		</dependency>
-    <dependency>
-      <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
-      <scope>test</scope>
-    </dependency>
 	</dependencies>
 </project>

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

@@ -2,38 +2,38 @@ package com.iluwatar.bridge;
 
 /**
  * 
- * The Bridge pattern can also be thought of as two layers of abstraction. With Bridge, you can
- * decouple an abstraction from its implementation so that the two can vary independently.
- * <p>
- * In Bridge pattern both abstraction ({@link MagicWeapon}) and implementation (
- * {@link MagicWeaponImpl}) have their own class hierarchies. The interface of the implementations
- * can be changed without affecting the clients.
+ * In Bridge pattern both abstraction ({@link MagicWeapon}) and implementation
+ * ({@link MagicWeaponImpl}) have their own class hierarchies. The interface of the
+ * implementations can be changed without affecting the clients.
  * 
  */
 public class App {
 
 	/**
 	 * Program entry point
-   * 
 	 * @param args command line args
 	 */
 	public static void main(String[] args) {
-    BlindingMagicWeapon blindingMagicWeapon = new BlindingMagicWeapon(new Excalibur());
+		BlindingMagicWeapon blindingMagicWeapon = new BlindingMagicWeapon(
+				new Excalibur());
 		blindingMagicWeapon.wield();
 		blindingMagicWeapon.blind();
 		blindingMagicWeapon.swing();
 		blindingMagicWeapon.unwield();
 
-    FlyingMagicWeapon flyingMagicWeapon = new FlyingMagicWeapon(new Mjollnir());
+		FlyingMagicWeapon flyingMagicWeapon = new FlyingMagicWeapon(
+				new Mjollnir());
 		flyingMagicWeapon.wield();
 		flyingMagicWeapon.fly();
 		flyingMagicWeapon.swing();
 		flyingMagicWeapon.unwield();
 
-    SoulEatingMagicWeapon soulEatingMagicWeapon = new SoulEatingMagicWeapon(new Stormbringer());
+		SoulEatingMagicWeapon soulEatingMagicWeapon = new SoulEatingMagicWeapon(
+				new Stormbringer());
 		soulEatingMagicWeapon.wield();
 		soulEatingMagicWeapon.swing();
 		soulEatingMagicWeapon.eatSoul();
 		soulEatingMagicWeapon.unwield();
+
 	}
 }

bridge/src/main/java/com/iluwatar/bridge/BlindingMagicWeapon.java

@@ -34,4 +34,5 @@ public class BlindingMagicWeapon extends MagicWeapon {
 	public void blind() {
 		getImp().blindImp();
 	}
+
 }

bridge/src/main/java/com/iluwatar/bridge/Excalibur.java

@@ -24,6 +24,8 @@ public class Excalibur extends BlindingMagicWeaponImpl {
 
 	@Override
 	public void blindImp() {
-    System.out.println("bright light streams from Excalibur blinding the enemy");
+		System.out
+				.println("bright light streams from Excalibur blinding the enemy");
 	}
+
 }

bridge/src/main/java/com/iluwatar/bridge/MagicWeapon.java

@@ -22,4 +22,5 @@ public abstract class MagicWeapon {
 	public MagicWeaponImpl getImp() {
 		return imp;
 	}
+
 }

bridge/src/main/java/com/iluwatar/bridge/Mjollnir.java

@@ -24,6 +24,8 @@ public class Mjollnir extends FlyingMagicWeaponImpl {
 
 	@Override
 	public void flyImp() {
-    System.out.println("Mjollnir hits the enemy in the air and returns back to the owner's hand");
+		System.out
+				.println("Mjollnir hits the enemy in the air and returns back to the owner's hand");
 	}
+
 }

bridge/src/main/java/com/iluwatar/bridge/Stormbringer.java

@@ -26,4 +26,5 @@ public class Stormbringer extends SoulEatingMagicWeaponImpl {
 	public void eatSoulImp() {
 		System.out.println("Stormbringer devours the enemy's soul");
 	}
+
 }

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

@@ -2,6 +2,8 @@ package com.iluwatar.bridge;
 
 import org.junit.Test;
 
+import com.iluwatar.bridge.App;
+
 /**
  * 
  * Application test

bridge/src/test/java/com/iluwatar/bridge/BlindingMagicWeaponTest.java

@@ -1,33 +0,0 @@
-package com.iluwatar.bridge;
-
-import org.junit.Test;
-
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.verifyNoMoreInteractions;
-import static org.mockito.internal.verification.VerificationModeFactory.times;
-
-/**
- * Date: 12/6/15 - 11:15 PM
- *
- * @author Jeroen Meulemeester
- */
-public class BlindingMagicWeaponTest extends MagicWeaponTest {
-
-  /**
-   * Invoke all possible actions on the weapon and check if the actions are executed on the actual
-   * underlying weapon implementation.
-   */
-  @Test
-  public void testExcalibur() throws Exception {
-    final Excalibur excalibur = spy(new Excalibur());
-    final BlindingMagicWeapon blindingMagicWeapon = new BlindingMagicWeapon(excalibur);
-
-    testBasicWeaponActions(blindingMagicWeapon, excalibur);
-
-    blindingMagicWeapon.blind();
-    verify(excalibur, times(1)).blindImp();
-    verifyNoMoreInteractions(excalibur);
-  }
-
-}

bridge/src/test/java/com/iluwatar/bridge/FlyingMagicWeaponTest.java

@@ -1,33 +0,0 @@
-package com.iluwatar.bridge;
-
-import org.junit.Test;
-
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.verifyNoMoreInteractions;
-import static org.mockito.internal.verification.VerificationModeFactory.times;
-
-/**
- * Date: 12/6/15 - 11:26 PM
- *
- * @author Jeroen Meulemeester
- */
-public class FlyingMagicWeaponTest extends MagicWeaponTest {
-
-  /**
-   * Invoke all possible actions on the weapon and check if the actions are executed on the actual
-   * underlying weapon implementation.
-   */
-  @Test
-  public void testMjollnir() throws Exception {
-    final Mjollnir mjollnir = spy(new Mjollnir());
-    final FlyingMagicWeapon flyingMagicWeapon = new FlyingMagicWeapon(mjollnir);
-
-    testBasicWeaponActions(flyingMagicWeapon, mjollnir);
-
-    flyingMagicWeapon.fly();
-    verify(mjollnir, times(1)).flyImp();
-    verifyNoMoreInteractions(mjollnir);
-  }
-
-}

bridge/src/test/java/com/iluwatar/bridge/MagicWeaponTest.java

@@ -1,42 +0,0 @@
-package com.iluwatar.bridge;
-
-import static org.junit.Assert.assertNotNull;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.verifyNoMoreInteractions;
-import static org.mockito.internal.verification.VerificationModeFactory.times;
-
-/**
- * Date: 12/6/15 - 11:28 PM
- *
- * @author Jeroen Meulemeester
- */
-public abstract class MagicWeaponTest {
-
-  /**
-   * Invoke the basic actions of the given weapon, and test if the underlying weapon implementation
-   * is invoked
-   *
-   * @param weaponImpl The spied weapon implementation where actions are bridged to
-   * @param weapon               The weapon, handled by the app
-   */
-  protected final void testBasicWeaponActions(final MagicWeapon weapon,
-                                              final MagicWeaponImpl weaponImpl) {
-    assertNotNull(weapon);
-    assertNotNull(weaponImpl);
-    assertNotNull(weapon.getImp());
-
-    weapon.swing();
-    verify(weaponImpl, times(1)).swingImp();
-    verifyNoMoreInteractions(weaponImpl);
-
-    weapon.wield();
-    verify(weaponImpl, times(1)).wieldImp();
-    verifyNoMoreInteractions(weaponImpl);
-
-    weapon.unwield();
-    verify(weaponImpl, times(1)).unwieldImp();
-    verifyNoMoreInteractions(weaponImpl);
-
-  }
-
-}

bridge/src/test/java/com/iluwatar/bridge/SoulEatingMagicWeaponTest.java

@@ -1,33 +0,0 @@
-package com.iluwatar.bridge;
-
-import org.junit.Test;
-
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.verifyNoMoreInteractions;
-import static org.mockito.internal.verification.VerificationModeFactory.times;
-
-/**
- * Date: 12/6/15 - 11:43 PM
- *
- * @author Jeroen Meulemeester
- */
-public class SoulEatingMagicWeaponTest extends MagicWeaponTest {
-
-  /**
-   * Invoke all possible actions on the weapon and check if the actions are executed on the actual
-   * underlying weapon implementation.
-   */
-  @Test
-  public void testStormBringer() throws Exception {
-    final Stormbringer stormbringer = spy(new Stormbringer());
-    final SoulEatingMagicWeapon soulEatingMagicWeapon = new SoulEatingMagicWeapon(stormbringer);
-
-    testBasicWeaponActions(soulEatingMagicWeapon, stormbringer);
-
-    soulEatingMagicWeapon.eatSoul();
-    verify(stormbringer, times(1)).eatSoulImp();
-    verifyNoMoreInteractions(stormbringer);
-  }
-
-}

builder/index.md

@@ -4,10 +4,7 @@ title: Builder
 folder: builder
 permalink: /patterns/builder/
 categories: Creational
-tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+tags: Java
 ---
 
 **Intent:** Separate the construction of a complex object from its
@@ -25,7 +22,3 @@ representations.
 
 * [java.lang.StringBuilder](http://docs.oracle.com/javase/8/docs/api/java/lang/StringBuilder.html)
 * [Apache Camel builders](https://github.com/apache/camel/tree/0e195428ee04531be27a0b659005e3aa8d159d23/camel-core/src/main/java/org/apache/camel/builder)
-
-**Credits**
-
-* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)

builder/pom.xml

@@ -1,11 +1,12 @@
 <?xml version="1.0"?>
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-    <version>1.9.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>builder</artifactId>
 	<dependencies>

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

@@ -4,51 +4,38 @@ import com.iluwatar.builder.Hero.HeroBuilder;
 
 /**
  * 
- * The intention of the Builder pattern is to find a solution to the telescoping constructor
- * anti-pattern. The telescoping constructor anti-pattern occurs when the increase of object
- * constructor parameter combination leads to an exponential list of constructors. Instead of using
- * numerous constructors, the builder pattern uses another object, a builder, that receives each
- * initialization parameter step by step and then returns the resulting constructed object at once.
+ * This is the Builder pattern variation as described by Joshua Bloch in
+ * Effective Java 2nd Edition.
  * <p>
- * The Builder pattern has another benefit. It can be used for objects that contain flat data (html
- * code, SQL query, X.509 certificate...), that is to say, data that can't be easily edited. This
- * type of data cannot be edited step by step and must be edited at once. The best way to construct
- * such an object is to use a builder class.
- * <p>
- * In this example we have the Builder pattern variation as described by Joshua Bloch in Effective
- * Java 2nd Edition.
- * <p>
- * We want to build {@link Hero} objects, but its construction is complex because of the many
- * parameters needed. To aid the user we introduce {@link HeroBuilder} class. {@link HeroBuilder}
- * takes the minimum parameters to build {@link Hero} object in its constructor. After that
- * additional configuration for the {@link Hero} object can be done using the fluent
- * {@link HeroBuilder} interface. When configuration is ready the build method is called to receive
- * the final {@link Hero} object.
+ * We want to build {@link Hero} objects, but its construction is complex because of the
+ * many parameters needed. To aid the user we introduce {@link HeroBuilder} class.
+ * {@link HeroBuilder} takes the minimum parameters to build {@link Hero} object in its
+ * constructor. After that additional configuration for the {@link Hero} object can be
+ * done using the fluent {@link HeroBuilder} interface. When configuration is ready the
+ * build method is called to receive the final {@link Hero} object.
  * 
  */
 public class App {
 
 	/**
 	 * Program entry point
-   * 
 	 * @param args command line args
 	 */
 	public static void main(String[] args) {
 
-    Hero mage =
-        new HeroBuilder(Profession.MAGE, "Riobard").withHairColor(HairColor.BLACK)
-            .withWeapon(Weapon.DAGGER).build();
+		Hero mage = new HeroBuilder(Profession.MAGE, "Riobard")
+				.withHairColor(HairColor.BLACK).withWeapon(Weapon.DAGGER)
+				.build();
 		System.out.println(mage);
 
-    Hero warrior =
-        new HeroBuilder(Profession.WARRIOR, "Amberjill").withHairColor(HairColor.BLOND)
-            .withHairType(HairType.LONG_CURLY).withArmor(Armor.CHAIN_MAIL).withWeapon(Weapon.SWORD)
-            .build();
+		Hero warrior = new HeroBuilder(Profession.WARRIOR, "Amberjill")
+				.withHairColor(HairColor.BLOND)
+				.withHairType(HairType.LONG_CURLY).withArmor(Armor.CHAIN_MAIL)
+				.withWeapon(Weapon.SWORD).build();
 		System.out.println(warrior);
 
-    Hero thief =
-        new HeroBuilder(Profession.THIEF, "Desmond").withHairType(HairType.BALD)
-            .withWeapon(Weapon.BOW).build();
+		Hero thief = new HeroBuilder(Profession.THIEF, "Desmond")
+				.withHairType(HairType.BALD).withWeapon(Weapon.BOW).build();
 		System.out.println(thief);
 
 	}

builder/src/main/java/com/iluwatar/builder/HairType.java

@@ -7,8 +7,7 @@ package com.iluwatar.builder;
  */
 public enum HairType {
 
-  BALD("bald"), SHORT("short"), CURLY("curly"), LONG_STRAIGHT("long straight"), LONG_CURLY(
-      "long curly");
+	BALD("bald"), SHORT("short"), CURLY("curly"), LONG_STRAIGHT("long straight"), LONG_CURLY("long curly");
 
     private String title;
 

builder/src/main/java/com/iluwatar/builder/Hero.java

@@ -93,12 +93,10 @@ public class Hero {
 		private Armor armor;
 		private Weapon weapon;
 
-    /**
-     * Constructor
-     */
 		public HeroBuilder(Profession profession, String name) {
 			if (profession == null || name == null) {
-        throw new IllegalArgumentException("profession and name can not be null");
+				throw new IllegalArgumentException(
+						"profession and name can not be null");
 			}
 			this.profession = profession;
 			this.name = name;

builder/src/main/java/com/iluwatar/builder/Profession.java

@@ -13,4 +13,5 @@ public enum Profession {
 	public String toString() {
 		return name().toLowerCase();
 	}
+
 }

builder/src/main/java/com/iluwatar/builder/Weapon.java

@@ -13,4 +13,5 @@ public enum Weapon {
 	public String toString() {
 		return name().toLowerCase();
 	}
+
 }

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

@@ -2,6 +2,8 @@ package com.iluwatar.builder;
 
 import org.junit.Test;
 
+import com.iluwatar. builder.App;
+
 /**
  * 
  * Application test

builder/src/test/java/com/iluwatar/builder/HeroTest.java

@@ -1,56 +0,0 @@
-package com.iluwatar.builder;
-
-import org.junit.Test;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-
-/**
- * Date: 12/6/15 - 11:01 PM
- *
- * @author Jeroen Meulemeester
- */
-public class HeroTest {
-
-  /**
-   * Test if we get the expected exception when trying to create a hero without a profession
-   */
-  @Test(expected = IllegalArgumentException.class)
-  public void testMissingProfession() throws Exception {
-    new Hero.HeroBuilder(null, "Sir without a job");
-  }
-
-  /**
-   * Test if we get the expected exception when trying to create a hero without a name
-   */
-  @Test(expected = IllegalArgumentException.class)
-  public void testMissingName() throws Exception {
-    new Hero.HeroBuilder(Profession.THIEF, null);
-  }
-
-  /**
-   * Test if the hero build by the builder has the correct attributes, as requested
-   */
-  @Test
-  public void testBuildHero() throws Exception {
-    final String heroName = "Sir Lancelot";
-
-    final Hero hero = new Hero.HeroBuilder(Profession.WARRIOR, heroName)
-        .withArmor(Armor.CHAIN_MAIL)
-        .withWeapon(Weapon.SWORD)
-        .withHairType(HairType.LONG_CURLY)
-        .withHairColor(HairColor.BLOND)
-        .build();
-
-    assertNotNull(hero);
-    assertNotNull(hero.toString());
-    assertEquals(Profession.WARRIOR, hero.getProfession());
-    assertEquals(heroName, hero.getName());
-    assertEquals(Armor.CHAIN_MAIL, hero.getArmor());
-    assertEquals(Weapon.SWORD, hero.getWeapon());
-    assertEquals(HairType.LONG_CURLY, hero.getHairType());
-    assertEquals(HairColor.BLOND, hero.getHairColor());
-
-  }
-
-}

business-delegate/index.md

@@ -4,9 +4,7 @@ title: Business Delegate
 folder: business-delegate
 permalink: /patterns/business-delegate/
 categories: Business Tier
-tags:
- - Java
- - Difficulty-Intermediate
+tags: Java
 ---
 
 **Intent:** The Business Delegate pattern adds an abstraction layer between

business-delegate/pom.xml

@@ -6,7 +6,7 @@
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-		<version>1.9.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>business-delegate</artifactId>
 	<dependencies>
@@ -15,10 +15,5 @@
 			<artifactId>junit</artifactId>
 			<scope>test</scope>
 		</dependency>
-		<dependency>
-			<groupId>org.mockito</groupId>
-			<artifactId>mockito-core</artifactId>
-			<scope>test</scope>
-		</dependency>
 	</dependencies>
 </project>

business-delegate/src/main/java/com/iluwatar/business/delegate/App.java

@@ -1,34 +1,29 @@
 package com.iluwatar.business.delegate;
 
 /**
- * The Business Delegate pattern adds an abstraction layer between the presentation and business
- * tiers. By using the pattern we gain loose coupling between the tiers. The Business Delegate
- * encapsulates knowledge about how to locate, connect to, and interact with the business objects
- * that make up the application.
  * 
- * <p>Some of the services the Business Delegate uses are instantiated directly, and some can be
- * retrieved through service lookups. The Business Delegate itself may contain business logic too
- * potentially tying together multiple service calls, exception handling, retrying etc.
+ * The Business Delegate pattern adds an abstraction layer between the presentation and business tiers.
+ * By using the pattern we gain loose coupling between the tiers. The Business Delegate encapsulates
+ * knowledge about how to locate, connect to, and interact with the business objects that make up
+ * the application.
+ * <p>
+ * Some of the services the Business Delegate uses are instantiated directly, and some can be retrieved
+ * through service lookups. The Business Delegate itself may contain business logic too potentially tying
+ * together multiple service calls, exception handling, retrying etc.
+ * <p>
+ * In this example the client ({@link Client}) utilizes a business delegate ({@link BusinessDelegate}) to execute a task.
+ * The Business Delegate then selects the appropriate service and makes the service call.
  *
- * <p>In this example the client ({@link Client}) utilizes a business delegate (
- * {@link BusinessDelegate}) to execute a task. The Business Delegate then selects the appropriate
- * service and makes the service call.
  */
 public class App {
 	
 	/**
-   * Program entry point.
-   *
+	 * Program entry point
 	 * @param args command line args
 	 */
 	public static void main(String[] args) {
 		
 		BusinessDelegate businessDelegate = new BusinessDelegate();
-    BusinessLookup businessLookup = new BusinessLookup();
-    businessLookup.setEjbService(new EjbService());
-    businessLookup.setJmsService(new JmsService());
-
-    businessDelegate.setLookupService(businessLookup);
 		businessDelegate.setServiceType(ServiceType.EJB);
 
 		Client client = new Client(businessDelegate);

business-delegate/src/main/java/com/iluwatar/business/delegate/BusinessDelegate.java

@@ -1,18 +1,16 @@
 package com.iluwatar.business.delegate;
 
 /**
+ * 
  * BusinessDelegate separates the presentation and business tiers
+ *
  */
 public class BusinessDelegate {
 	
-  private BusinessLookup lookupService;
+	private BusinessLookup lookupService = new BusinessLookup();
 	private BusinessService businessService;
 	private ServiceType serviceType;
 
-  public void setLookupService(BusinessLookup businessLookup) {
-    this.lookupService = businessLookup;
-  }
-
 	public void setServiceType(ServiceType serviceType) {
 		this.serviceType = serviceType;
 	}

business-delegate/src/main/java/com/iluwatar/business/delegate/BusinessLookup.java

@@ -1,31 +1,17 @@
 package com.iluwatar.business.delegate;
 
 /**
- * Class for performing service lookups.
+ * 
+ * Class for performing service lookups
+ *
  */
 public class BusinessLookup {
 
-  private EjbService ejbService;
-
-  private JmsService jmsService;
-
-  /**
-   * @param serviceType Type of service instance to be returned.
-   * @return Service instance.
-   */
 	public BusinessService getBusinessService(ServiceType serviceType) {
 		if (serviceType.equals(ServiceType.EJB)) {
-      return ejbService;
+			return new EjbService();
 		} else {
-      return jmsService;
+			return new JmsService();
 		}
 	}
-
-  public void setJmsService(JmsService jmsService) {
-    this.jmsService = jmsService;
-  }
-
-  public void setEjbService(EjbService ejbService) {
-    this.ejbService = ejbService;
-  }
 }

business-delegate/src/test/java/com/iluwatar/business/delegate/AppTest.java

@@ -0,0 +1,19 @@
+package com.iluwatar.business.delegate;
+
+import org.junit.Test;
+
+import com.iluwatar.business.delegate.App;
+
+/**
+ * 
+ * Application test
+ *
+ */
+public class AppTest {
+	
+	@Test
+	public void test() {
+		String[] args = {};
+		App.main(args);
+	}
+}

business-delegate/src/test/java/com/iluwatar/business/delegate/BusinessDelegateTest.java

@@ -1,78 +0,0 @@
-package com.iluwatar.business.delegate;
-
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.times;
-import static org.mockito.Mockito.verify;
-
-import org.junit.Before;
-import org.junit.Test;
-
-/**
- * The Business Delegate pattern adds an abstraction layer between the presentation and business
- * tiers. By using the pattern we gain loose coupling between the tiers. The Business Delegate
- * encapsulates knowledge about how to locate, connect to, and interact with the business objects
- * that make up the application.
- * 
- * <p>Some of the services the Business Delegate uses are instantiated directly, and some can be
- * retrieved through service lookups. The Business Delegate itself may contain business logic too
- * potentially tying together multiple service calls, exception handling, retrying etc.
- */
-public class BusinessDelegateTest {
-
-  private EjbService ejbService;
-
-  private JmsService jmsService;
-
-  private BusinessLookup businessLookup;
-
-  private BusinessDelegate businessDelegate;
-
-  /**
-   * This method sets up the instance variables of this test class. It is executed before the
-   * execution of every test.
-   */
-  @Before
-  public void setup() {
-    ejbService = spy(new EjbService());
-    jmsService = spy(new JmsService());
-
-    businessLookup = spy(new BusinessLookup());
-    businessLookup.setEjbService(ejbService);
-    businessLookup.setJmsService(jmsService);
-
-    businessDelegate = spy(new BusinessDelegate());
-    businessDelegate.setLookupService(businessLookup);
-  }
-
-  /**
-   * In this example the client ({@link Client}) utilizes a business delegate (
-   * {@link BusinessDelegate}) to execute a task. The Business Delegate then selects the appropriate
-   * service and makes the service call.
-   */
-  @Test
-  public void testBusinessDelegate() {
-
-    // setup a client object
-    Client client = new Client(businessDelegate);
-
-    // set the service type
-    businessDelegate.setServiceType(ServiceType.EJB);
-
-    // action
-    client.doTask();
-
-    // verifying that the businessDelegate was used by client during doTask() method.
-    verify(businessDelegate).doTask();
-    verify(ejbService).doProcessing();
-
-    // set the service type
-    businessDelegate.setServiceType(ServiceType.JMS);
-
-    // action
-    client.doTask();
-
-    // verifying that the businessDelegate was used by client during doTask() method.
-    verify(businessDelegate, times(2)).doTask();
-    verify(jmsService).doProcessing();
-  }
-}

caching/.gitignore

@@ -1 +0,0 @@
-/target/

caching/etc/caching.ucls

@@ -1,106 +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">  
-  <class id="1" language="java" name="main.java.com.wssia.caching.App" project="CachingPatterns" 
-    file="/CachingPatterns/src/main/java/com/wssia/caching/App.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="249" y="150"/>    
-    <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="main.java.com.wssia.caching.AppManager" project="CachingPatterns" 
-    file="/CachingPatterns/src/main/java/com/wssia/caching/AppManager.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="502" y="163"/>    
-    <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="main.java.com.wssia.caching.CacheStore" project="CachingPatterns" 
-    file="/CachingPatterns/src/main/java/com/wssia/caching/CacheStore.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="537" y="436"/>    
-    <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="4" language="java" name="main.java.com.wssia.caching.CachingPolicy" project="CachingPatterns" 
-    file="/CachingPatterns/src/main/java/com/wssia/caching/CachingPolicy.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="789" y="162"/>    
-    <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="5" language="java" name="main.java.com.wssia.caching.DBManager" project="CachingPatterns" 
-    file="/CachingPatterns/src/main/java/com/wssia/caching/DBManager.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="1137" y="134"/>    
-    <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="main.java.com.wssia.caching.LRUCache" project="CachingPatterns" 
-    file="/CachingPatterns/src/main/java/com/wssia/caching/LRUCache.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="884" y="435"/>    
-    <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="7" language="java" name="main.java.com.wssia.caching.UserAccount" project="CachingPatterns" 
-    file="/CachingPatterns/src/main/java/com/wssia/caching/UserAccount.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="1140" 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>  
-  </class>  
-  <class id="8" language="java" name="test.java.com.wssia.caching.AppTest" project="CachingPatterns" 
-    file="/CachingPatterns/src/test/java/com/wssia/caching/AppTest.java" binary="false" corner="BOTTOM_RIGHT">    
-    <position height="-1" width="-1" x="251" 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>  
-  <association id="9">    
-    <end type="SOURCE" refId="2" navigable="false">      
-      <attribute id="10" name="cachingPolicy"/>      
-      <multiplicity id="11" minimum="0" maximum="1"/>    
-    </end>    
-    <end type="TARGET" refId="4" navigable="true"/>    
-    <display labels="true" multiplicity="true"/>  
-  </association>  
-  <association id="12">    
-    <end type="SOURCE" refId="8" navigable="false">      
-      <attribute id="13" name="app"/>      
-      <multiplicity id="14" minimum="0" maximum="1"/>    
-    </end>    
-    <end type="TARGET" refId="1" navigable="true"/>    
-    <display labels="true" multiplicity="true"/>  
-  </association>  
-  <association id="15">    
-    <end type="SOURCE" refId="3" navigable="false">      
-      <attribute id="16" name="cache"/>      
-      <multiplicity id="17" minimum="0" maximum="1"/>    
-    </end>    
-    <end type="TARGET" refId="6" navigable="true"/>    
-    <display labels="true" multiplicity="true"/>  
-  </association>  
-  <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>

caching/index.md

@@ -1,26 +0,0 @@
----
-layout: pattern
-title: Caching
-folder: caching
-permalink: /patterns/caching/
-categories: Other
-tags:
- - Java
- - Difficulty-Intermediate
- - Performance
----
-
-**Intent:** To avoid expensive re-acquisition of resources by not releasing
-the resources immediately after their use. The resources retain their identity, are kept in some
-fast-access storage, and are re-used to avoid having to acquire them again.
-
-![alt text](./etc/caching.png "Caching")
-
-**Applicability:** Use the Caching pattern(s) when
-
-* Repetitious acquisition, initialization, and release of the same resource causes unnecessary performance overhead.
-
-**Credits**
-
-* [Write-through, write-around, write-back: Cache explained](http://www.computerweekly.com/feature/Write-through-write-around-write-back-Cache-explained)
-* [Read-Through, Write-Through, Write-Behind, and Refresh-Ahead Caching](https://docs.oracle.com/cd/E15357_01/coh.360/e15723/cache_rtwtwbra.htm#COHDG5177)

caching/pom.xml

@@ -1,51 +0,0 @@
-<?xml version="1.0"?>
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
-  <modelVersion>4.0.0</modelVersion>
-  <parent>
-    <groupId>com.iluwatar</groupId>
-    <artifactId>java-design-patterns</artifactId>
-    <version>1.9.0</version>
-  </parent>
-  <artifactId>caching</artifactId>
-  <dependencies>
-    <dependency>
-      <groupId>junit</groupId>
-      <artifactId>junit</artifactId>
-      <scope>test</scope>
-    </dependency>
-    <dependency>
-      <groupId>org.mongodb</groupId>
-      <artifactId>mongodb-driver</artifactId>
-      <version>3.0.4</version>
-    </dependency>
-    <dependency>
-      <groupId>org.mongodb</groupId>
-      <artifactId>mongodb-driver-core</artifactId>
-      <version>3.0.4</version>
-    </dependency>
-    <dependency>
-      <groupId>org.mongodb</groupId>
-      <artifactId>bson</artifactId>
-      <version>3.0.4</version>
-    </dependency>
-  </dependencies>
-  <!--
-    Due to the use of MongoDB in the test of this pattern, TRAVIS and/or MAVEN might fail if the DB connection is
-    not open for the JUnit test. To avoid disrupting the compilation process, the surefire plug-in was used
-    to SKIP the running of the JUnit tests for this pattern. To ACTIVATE the running of the tests, change the
-    skipTests (below) flag to 'false' and vice-versa.
-  -->
-  <build>
-    <plugins>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-surefire-plugin</artifactId>
-        <version>2.19</version>
-        <configuration>
-          <skipTests>false</skipTests>
-        </configuration>
-      </plugin>
-    </plugins>
-  </build>
-</project>

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

@@ -1,117 +0,0 @@
-package com.iluwatar.caching;
-
-/**
- *
- * The Caching pattern describes how to avoid expensive re-acquisition of resources by not releasing
- * the resources immediately after their use. The resources retain their identity, are kept in some
- * fast-access storage, and are re-used to avoid having to acquire them again. There are three main
- * caching strategies/techniques in this pattern; each with their own pros and cons. They are:
- * <code>write-through</code> which writes data to the cache and DB in a single transaction,
- * <code>write-around</code> which writes data immediately into the DB instead of the cache, and
- * <code>write-behind</code> which writes data into the cache initially whilst the data is only
- * written into the DB when the cache is full. The <code>read-through</code> strategy is also
- * included in the mentioned three strategies -- returns data from the cache to the caller <b>if</b>
- * it exists <b>else</b> queries from DB and stores it into the cache for future use. These
- * strategies determine when the data in the cache should be written back to the backing store (i.e.
- * Database) and help keep both data sources synchronized/up-to-date. This pattern can improve
- * performance and also helps to maintain consistency between data held in the cache and the data in
- * the underlying data store.
- * <p>
- * In this example, the user account ({@link UserAccount}) entity is used as the underlying
- * application data. The cache itself is implemented as an internal (Java) data structure. It adopts
- * a Least-Recently-Used (LRU) strategy for evicting data from itself when its full. The three
- * strategies are individually tested. The testing of the cache is restricted towards saving and
- * querying of user accounts from the underlying data store ( {@link DbManager}). The main class (
- * {@link App} is not aware of the underlying mechanics of the application (i.e. save and query) and
- * whether the data is coming from the cache or the DB (i.e. separation of concern). The AppManager
- * ({@link AppManager}) handles the transaction of data to-and-from the underlying data store
- * (depending on the preferred caching policy/strategy).
- *
- * <i>App --> AppManager --> CacheStore/LRUCache/CachingPolicy --> DBManager</i>
- * </p>
- *
- * @see CacheStore
- * @See LRUCache
- * @see CachingPolicy
- *
- */
-public class App {
-
-  /**
-   * Program entry point
-   *
-   * @param args command line args
-   */
-  public static void main(String[] args) {
-    AppManager.initDb(false); // VirtualDB (instead of MongoDB) was used in running the JUnit tests
-                              // and the App class to avoid Maven compilation errors. Set flag to
-                              // true to run the tests with MongoDB (provided that MongoDB is
-                              // installed and socket connection is open).
-    AppManager.initCacheCapacity(3);
-    App app = new App();
-    app.useReadAndWriteThroughStrategy();
-    app.useReadThroughAndWriteAroundStrategy();
-    app.useReadThroughAndWriteBehindStrategy();
-  }
-
-  /**
-   * Read-through and write-through
-   */
-  public void useReadAndWriteThroughStrategy() {
-    System.out.println("# CachingPolicy.THROUGH");
-    AppManager.initCachingPolicy(CachingPolicy.THROUGH);
-
-    UserAccount userAccount1 = new UserAccount("001", "John", "He is a boy.");
-
-    AppManager.save(userAccount1);
-    System.out.println(AppManager.printCacheContent());
-    AppManager.find("001");
-    AppManager.find("001");
-  }
-
-  /**
-   * Read-through and write-around
-   */
-  public void useReadThroughAndWriteAroundStrategy() {
-    System.out.println("# CachingPolicy.AROUND");
-    AppManager.initCachingPolicy(CachingPolicy.AROUND);
-
-    UserAccount userAccount2 = new UserAccount("002", "Jane", "She is a girl.");
-
-    AppManager.save(userAccount2);
-    System.out.println(AppManager.printCacheContent());
-    AppManager.find("002");
-    System.out.println(AppManager.printCacheContent());
-    userAccount2 = AppManager.find("002");
-    userAccount2.setUserName("Jane G.");
-    AppManager.save(userAccount2);
-    System.out.println(AppManager.printCacheContent());
-    AppManager.find("002");
-    System.out.println(AppManager.printCacheContent());
-    AppManager.find("002");
-  }
-
-  /**
-   * Read-through and write-behind
-   */
-  public void useReadThroughAndWriteBehindStrategy() {
-    System.out.println("# CachingPolicy.BEHIND");
-    AppManager.initCachingPolicy(CachingPolicy.BEHIND);
-
-    UserAccount userAccount3 = new UserAccount("003", "Adam", "He likes food.");
-    UserAccount userAccount4 = new UserAccount("004", "Rita", "She hates cats.");
-    UserAccount userAccount5 = new UserAccount("005", "Isaac", "He is allergic to mustard.");
-
-    AppManager.save(userAccount3);
-    AppManager.save(userAccount4);
-    AppManager.save(userAccount5);
-    System.out.println(AppManager.printCacheContent());
-    AppManager.find("003");
-    System.out.println(AppManager.printCacheContent());
-    UserAccount userAccount6 = new UserAccount("006", "Yasha", "She is an only child.");
-    AppManager.save(userAccount6);
-    System.out.println(AppManager.printCacheContent());
-    AppManager.find("004");
-    System.out.println(AppManager.printCacheContent());
-  }
-}

caching/src/main/java/com/iluwatar/caching/AppManager.java

@@ -1,87 +0,0 @@
-package com.iluwatar.caching;
-
-import java.text.ParseException;
-
-/**
- *
- * AppManager helps to bridge the gap in communication between the main class and the application's
- * back-end. DB connection is initialized through this class. The chosen caching strategy/policy is
- * also initialized here. Before the cache can be used, the size of the cache has to be set.
- * Depending on the chosen caching policy, AppManager will call the appropriate function in the
- * CacheStore class.
- *
- */
-public class AppManager {
-
-  private static CachingPolicy cachingPolicy;
-
-  private AppManager() {
-  }
-
-  /**
-   *
-   * Developer/Tester is able to choose whether the application should use MongoDB as its underlying
-   * data storage or a simple Java data structure to (temporarily) store the data/objects during
-   * runtime.
-   */
-  public static void initDb(boolean useMongoDb) {
-    if (useMongoDb) {
-      try {
-        DbManager.connect();
-      } catch (ParseException e) {
-        e.printStackTrace();
-      }
-    } else {
-      DbManager.createVirtualDb();
-    }
-  }
-
-  /**
-   * Initialize caching policy
-   */
-  public static void initCachingPolicy(CachingPolicy policy) {
-    cachingPolicy = policy;
-    if (cachingPolicy == CachingPolicy.BEHIND) {
-      Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
-        @Override
-        public void run() {
-          CacheStore.flushCache();
-        }
-      }));
-    }
-    CacheStore.clearCache();
-  }
-
-  public static void initCacheCapacity(int capacity) {
-    CacheStore.initCapacity(capacity);
-  }
-
-  /**
-   * Find user account
-   */
-  public static UserAccount find(String userId) {
-    if (cachingPolicy == CachingPolicy.THROUGH || cachingPolicy == CachingPolicy.AROUND) {
-      return CacheStore.readThrough(userId);
-    } else if (cachingPolicy == CachingPolicy.BEHIND) {
-      return CacheStore.readThroughWithWriteBackPolicy(userId);
-    }
-    return null;
-  }
-
-  /**
-   * Save user account
-   */
-  public static void save(UserAccount userAccount) {
-    if (cachingPolicy == CachingPolicy.THROUGH) {
-      CacheStore.writeThrough(userAccount);
-    } else if (cachingPolicy == CachingPolicy.AROUND) {
-      CacheStore.writeAround(userAccount);
-    } else if (cachingPolicy == CachingPolicy.BEHIND) {
-      CacheStore.writeBehind(userAccount);
-    }
-  }
-
-  public static String printCacheContent() {
-    return CacheStore.print();
-  }
-}

caching/src/main/java/com/iluwatar/caching/CacheStore.java

@@ -1,134 +0,0 @@
-package com.iluwatar.caching;
-
-import java.util.ArrayList;
-
-/**
- *
- * The caching strategies are implemented in this class.
- *
- */
-public class CacheStore {
-
-  static LruCache cache = null;
-
-  private CacheStore() {
-  }
-
-  /**
-   * Init cache capacity
-   */
-  public static void initCapacity(int capacity) {
-    if (null == cache) {
-      cache = new LruCache(capacity);
-    } else {
-      cache.setCapacity(capacity);
-    }
-  }
-
-  /**
-   * Get user account using read-through cache
-   */
-  public static UserAccount readThrough(String userId) {
-    if (cache.contains(userId)) {
-      System.out.println("# Cache Hit!");
-      return cache.get(userId);
-    }
-    System.out.println("# Cache Miss!");
-    UserAccount userAccount = DbManager.readFromDb(userId);
-    cache.set(userId, userAccount);
-    return userAccount;
-  }
-
-  /**
-   * Get user account using write-through cache
-   */
-  public static void writeThrough(UserAccount userAccount) {
-    if (cache.contains(userAccount.getUserId())) {
-      DbManager.updateDb(userAccount);
-    } else {
-      DbManager.writeToDb(userAccount);
-    }
-    cache.set(userAccount.getUserId(), userAccount);
-  }
-
-  /**
-   * Get user account using write-around cache
-   */
-  public static void writeAround(UserAccount userAccount) {
-    if (cache.contains(userAccount.getUserId())) {
-      DbManager.updateDb(userAccount);
-      cache.invalidate(userAccount.getUserId()); // Cache data has been updated -- remove older
-                                                 // version from cache.
-    } else {
-      DbManager.writeToDb(userAccount);
-    }
-  }
-
-  /**
-   * Get user account using read-through cache with write-back policy
-   */
-  public static UserAccount readThroughWithWriteBackPolicy(String userId) {
-    if (cache.contains(userId)) {
-      System.out.println("# Cache Hit!");
-      return cache.get(userId);
-    }
-    System.out.println("# Cache Miss!");
-    UserAccount userAccount = DbManager.readFromDb(userId);
-    if (cache.isFull()) {
-      System.out.println("# Cache is FULL! Writing LRU data to DB...");
-      UserAccount toBeWrittenToDb = cache.getLruData();
-      DbManager.upsertDb(toBeWrittenToDb);
-    }
-    cache.set(userId, userAccount);
-    return userAccount;
-  }
-
-  /**
-   * Set user account
-   */
-  public static void writeBehind(UserAccount userAccount) {
-    if (cache.isFull() && !cache.contains(userAccount.getUserId())) {
-      System.out.println("# Cache is FULL! Writing LRU data to DB...");
-      UserAccount toBeWrittenToDb = cache.getLruData();
-      DbManager.upsertDb(toBeWrittenToDb);
-    }
-    cache.set(userAccount.getUserId(), userAccount);
-  }
-
-  /**
-   * Clears cache
-   */
-  public static void clearCache() {
-    if (null != cache) {
-      cache.clear();
-    }
-  }
-
-  /**
-   * Writes remaining content in the cache into the DB.
-   */
-  public static void flushCache() {
-    System.out.println("# flushCache...");
-    if (null == cache) {
-      return;
-    }
-    ArrayList<UserAccount> listOfUserAccounts = cache.getCacheDataInListForm();
-    for (UserAccount userAccount : listOfUserAccounts) {
-      DbManager.upsertDb(userAccount);
-    }
-  }
-
-  /**
-   * Print user accounts
-   */
-  public static String print() {
-    ArrayList<UserAccount> listOfUserAccounts = cache.getCacheDataInListForm();
-    StringBuilder sb = new StringBuilder();
-    sb.append("\n--CACHE CONTENT--\n");
-    for (UserAccount userAccount : listOfUserAccounts) {
-      sb.append(userAccount.toString() + "\n");
-    }
-    sb.append("----\n");
-    return sb.toString();
-  }
-}

caching/src/main/java/com/iluwatar/caching/CachingPolicy.java

@@ -1,20 +0,0 @@
-package com.iluwatar.caching;
-
-/**
- *
- * Enum class containing the three caching strategies implemented in the pattern.
- *
- */
-public enum CachingPolicy {
-  THROUGH("through"), AROUND("around"), BEHIND("behind");
-
-  private String policy;
-
-  private CachingPolicy(String policy) {
-    this.policy = policy;
-  }
-
-  public String getPolicy() {
-    return policy;
-  }
-}

caching/src/main/java/com/iluwatar/caching/DbManager.java

@@ -1,143 +0,0 @@
-package com.iluwatar.caching;
-
-import java.text.ParseException;
-import java.util.HashMap;
-
-import org.bson.Document;
-
-import com.mongodb.MongoClient;
-import com.mongodb.client.FindIterable;
-import com.mongodb.client.MongoDatabase;
-import com.mongodb.client.model.UpdateOptions;
-
-/**
- *
- * <p>DBManager handles the communication with the underlying data store i.e. Database. It contains the
- * implemented methods for querying, inserting, and updating data. MongoDB was used as the database
- * for the application.</p>
- * 
- * <p>Developer/Tester is able to choose whether the application should use MongoDB as its underlying
- * data storage (connect()) or a simple Java data structure to (temporarily) store the data/objects
- * during runtime (createVirtualDB()).</p>
- * 
- */
-public class DbManager {
-
-  private static MongoClient mongoClient;
-  private static MongoDatabase db;
-  private static boolean useMongoDB;
-
-  private static HashMap<String, UserAccount> virtualDB;
-
-  private DbManager() {
-  }
-
-  /**
-   * Create DB
-   */
-  public static void createVirtualDb() {
-    useMongoDB = false;
-    virtualDB = new HashMap<String, UserAccount>();
-  }
-
-  /**
-   * Connect to DB
-   */
-  public static void connect() throws ParseException {
-    useMongoDB = true;
-    mongoClient = new MongoClient();
-    db = mongoClient.getDatabase("test");
-  }
-
-  /**
-   * Read user account from DB
-   */
-  public static UserAccount readFromDb(String userId) {
-    if (!useMongoDB) {
-      if (virtualDB.containsKey(userId)) {
-        return virtualDB.get(userId);
-      }
-      return null;
-    }
-    if (null == db) {
-      try {
-        connect();
-      } catch (ParseException e) {
-        e.printStackTrace();
-      }
-    }
-    FindIterable<Document> iterable =
-        db.getCollection("user_accounts").find(new Document("userID", userId));
-    if (iterable == null) {
-      return null;
-    }
-    Document doc = iterable.first();
-    UserAccount userAccount =
-        new UserAccount(userId, doc.getString("userName"), doc.getString("additionalInfo"));
-    return userAccount;
-  }
-
-  /**
-   * Write user account to DB
-   */
-  public static void writeToDb(UserAccount userAccount) {
-    if (!useMongoDB) {
-      virtualDB.put(userAccount.getUserId(), userAccount);
-      return;
-    }
-    if (null == db) {
-      try {
-        connect();
-      } catch (ParseException e) {
-        e.printStackTrace();
-      }
-    }
-    db.getCollection("user_accounts").insertOne(
-        new Document("userID", userAccount.getUserId()).append("userName",
-            userAccount.getUserName()).append("additionalInfo", userAccount.getAdditionalInfo()));
-  }
-
-  /**
-   * Update DB
-   */
-  public static void updateDb(UserAccount userAccount) {
-    if (!useMongoDB) {
-      virtualDB.put(userAccount.getUserId(), userAccount);
-      return;
-    }
-    if (null == db) {
-      try {
-        connect();
-      } catch (ParseException e) {
-        e.printStackTrace();
-      }
-    }
-    db.getCollection("user_accounts").updateOne(
-        new Document("userID", userAccount.getUserId()),
-        new Document("$set", new Document("userName", userAccount.getUserName()).append(
-            "additionalInfo", userAccount.getAdditionalInfo())));
-  }
-
-  /**
-   *
-   * Insert data into DB if it does not exist. Else, update it.
-   */
-  public static void upsertDb(UserAccount userAccount) {
-    if (!useMongoDB) {
-      virtualDB.put(userAccount.getUserId(), userAccount);
-      return;
-    }
-    if (null == db) {
-      try {
-        connect();
-      } catch (ParseException e) {
-        e.printStackTrace();
-      }
-    }
-    db.getCollection("user_accounts").updateOne(
-        new Document("userID", userAccount.getUserId()),
-        new Document("$set", new Document("userID", userAccount.getUserId()).append("userName",
-            userAccount.getUserName()).append("additionalInfo", userAccount.getAdditionalInfo())),
-        new UpdateOptions().upsert(true));
-  }
-}

caching/src/main/java/com/iluwatar/caching/LruCache.java

@@ -1,163 +0,0 @@
-package com.iluwatar.caching;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-
-/**
- *
- * Data structure/implementation of the application's cache. The data structure consists of a hash
- * table attached with a doubly linked-list. The linked-list helps in capturing and maintaining the
- * LRU data in the cache. When a data is queried (from the cache), added (to the cache), or updated,
- * the data is moved to the front of the list to depict itself as the most-recently-used data. The
- * LRU data is always at the end of the list.
- *
- */
-public class LruCache {
-
-  class Node {
-    String userId;
-    UserAccount userAccount;
-    Node previous;
-    Node next;
-
-    public Node(String userId, UserAccount userAccount) {
-      this.userId = userId;
-      this.userAccount = userAccount;
-    }
-  }
-
-  int capacity;
-  HashMap<String, Node> cache = new HashMap<String, Node>();
-  Node head = null;
-  Node end = null;
-
-  public LruCache(int capacity) {
-    this.capacity = capacity;
-  }
-
-  /**
-   * Get user account
-   */
-  public UserAccount get(String userId) {
-    if (cache.containsKey(userId)) {
-      Node node = cache.get(userId);
-      remove(node);
-      setHead(node);
-      return node.userAccount;
-    }
-    return null;
-  }
-
-  /**
-   *
-   * Remove node from linked list.
-   */
-  public void remove(Node node) {
-    if (node.previous != null) {
-      node.previous.next = node.next;
-    } else {
-      head = node.next;
-    }
-    if (node.next != null) {
-      node.next.previous = node.previous;
-    } else {
-      end = node.previous;
-    }
-  }
-
-  /**
-   *
-   * Move node to the front of the list.
-   */
-  public void setHead(Node node) {
-    node.next = head;
-    node.previous = null;
-    if (head != null) {
-      head.previous = node;
-    }
-    head = node;
-    if (end == null) {
-      end = head;
-    }
-  }
-
-  /**
-   * Set user account
-   */
-  public void set(String userId, UserAccount userAccount) {
-    if (cache.containsKey(userId)) {
-      Node old = cache.get(userId);
-      old.userAccount = userAccount;
-      remove(old);
-      setHead(old);
-    } else {
-      Node newNode = new Node(userId, userAccount);
-      if (cache.size() >= capacity) {
-        System.out.println("# Cache is FULL! Removing " + end.userId + " from cache...");
-        cache.remove(end.userId); // remove LRU data from cache.
-        remove(end);
-        setHead(newNode);
-      } else {
-        setHead(newNode);
-      }
-      cache.put(userId, newNode);
-    }
-  }
-
-  public boolean contains(String userId) {
-    return cache.containsKey(userId);
-  }
-
-  /**
-   * Invalidate cache for user
-   */
-  public void invalidate(String userId) {
-    System.out.println("# " + userId + " has been updated! Removing older version from cache...");
-    Node toBeRemoved = cache.get(userId);
-    remove(toBeRemoved);
-    cache.remove(userId);
-  }
-
-  public boolean isFull() {
-    return cache.size() >= capacity;
-  }
-
-  public UserAccount getLruData() {
-    return end.userAccount;
-  }
-
-  /**
-   * Clear cache
-   */
-  public void clear() {
-    head = null;
-    end = null;
-    cache.clear();
-  }
-
-  /**
-   *
-   * Returns cache data in list form.
-   */
-  public ArrayList<UserAccount> getCacheDataInListForm() {
-    ArrayList<UserAccount> listOfCacheData = new ArrayList<UserAccount>();
-    Node temp = head;
-    while (temp != null) {
-      listOfCacheData.add(temp.userAccount);
-      temp = temp.next;
-    }
-    return listOfCacheData;
-  }
-
-  /**
-   * Set cache capacity
-   */
-  public void setCapacity(int newCapacity) {
-    if (capacity > newCapacity) {
-      clear(); // Behavior can be modified to accommodate for decrease in cache size. For now, we'll
-               // just clear the cache.
-    } else {
-      this.capacity = newCapacity;
-    }
-  }
-}

caching/src/main/java/com/iluwatar/caching/UserAccount.java

@@ -1,50 +0,0 @@
-package com.iluwatar.caching;
-
-/**
- *
- * Entity class (stored in cache and DB) used in the application.
- *
- */
-public class UserAccount {
-  private String userId;
-  private String userName;
-  private String additionalInfo;
-
-  /**
-   * Constructor
-   */
-  public UserAccount(String userId, String userName, String additionalInfo) {
-    this.userId = userId;
-    this.userName = userName;
-    this.additionalInfo = additionalInfo;
-  }
-
-  public String getUserId() {
-    return userId;
-  }
-
-  public void setUserId(String userId) {
-    this.userId = userId;
-  }
-
-  public String getUserName() {
-    return userName;
-  }
-
-  public void setUserName(String userName) {
-    this.userName = userName;
-  }
-
-  public String getAdditionalInfo() {
-    return additionalInfo;
-  }
-
-  public void setAdditionalInfo(String additionalInfo) {
-    this.additionalInfo = additionalInfo;
-  }
-
-  @Override
-  public String toString() {
-    return userId + ", " + userName + ", " + additionalInfo;
-  }
-}

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

@@ -1,41 +0,0 @@
-package com.iluwatar.caching;
-
-import org.junit.Before;
-import org.junit.Test;
-
-/**
- *
- * Application test
- *
- */
-public class AppTest {
-  App app;
-
-  /**
-   * Setup of application test includes: initializing DB connection and cache size/capacity.
-   */
-  @Before
-  public void setUp() {
-    AppManager.initDb(false); // VirtualDB (instead of MongoDB) was used in running the JUnit tests
-                              // to avoid Maven compilation errors. Set flag to true to run the
-                              // tests with MongoDB (provided that MongoDB is installed and socket
-                              // connection is open).
-    AppManager.initCacheCapacity(3);
-    app = new App();
-  }
-
-  @Test
-  public void testReadAndWriteThroughStrategy() {
-    app.useReadAndWriteThroughStrategy();
-  }
-
-  @Test
-  public void testReadThroughAndWriteAroundStrategy() {
-    app.useReadThroughAndWriteAroundStrategy();
-  }
-
-  @Test
-  public void testReadThroughAndWriteBehindStrategy() {
-    app.useReadThroughAndWriteBehindStrategy();
-  }
-}

callback/index.md

@@ -4,11 +4,7 @@ title: Callback
 folder: callback
 permalink: /patterns/callback/
 categories: Other
-tags:
- - Java
- - Difficulty-Beginner
- - Functional
- - Idiom
+tags: Java
 ---
 
 **Intent:** Callback is a piece of executable code that is passed as an

callback/pom.xml

@@ -1,11 +1,12 @@
 <?xml version="1.0"?>
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-    <version>1.9.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>callback</artifactId>
 	<dependencies>

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

@@ -2,16 +2,12 @@ package com.iluwatar.callback;
 
 /**
  * 
- * Callback pattern is more native for functional languages where functions are treated as
- * first-class citizens. Prior to Java 8 callbacks can be simulated using simple (alike command)
- * interfaces.
+ * Callback pattern is more native for functional languages where functions are treated as first-class citizens.
+ * Prior to Java 8 callbacks can be simulated using simple (alike command) interfaces.
  * 
  */
 public class App {
 
-  /**
-   * Program entry point
-   */
 	public static void main(String[] args) {
 		Task task = new SimpleTask();
 		Callback callback = new Callback() {

callback/src/main/java/com/iluwatar/callback/Callback.java

@@ -7,5 +7,5 @@ package com.iluwatar.callback;
  */
 public interface Callback {
 
-  void call();
+	public void call();
 }

callback/src/main/java/com/iluwatar/callback/SimpleTask.java

@@ -9,6 +9,7 @@ public class SimpleTask extends Task {
 
 	@Override
 	public void execute() {
-    System.out.println("Perform some important activity and after call the callback method.");
+		System.out.println("Perform some important activity.");
 	}
+
 }

callback/src/main/java/com/iluwatar/callback/Task.java

@@ -7,9 +7,6 @@ package com.iluwatar.callback;
  */
 public abstract class Task {
 
-  /**
-   * Execute with callback
-   */
 	public final void executeWith(Callback callback) {
 		execute();
 		if (callback != null) {

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

@@ -2,38 +2,18 @@ package com.iluwatar.callback;
 
 import org.junit.Test;
 
-import static org.junit.Assert.assertEquals;
+import com.iluwatar.callback.App;
 
 /**
- * Add a field as a counter. Every time the callback method is called increment this field. Unit
- * test checks that the field is being incremented.
  * 
- * Could be done with mock objects as well where the call method call is verified.
+ * Application test
+ *
  */
 public class AppTest {
 
-  private Integer callingCount = 0;
-
 	@Test
 	public void test() {
-    Callback callback = new Callback() {
-      @Override
-      public void call() {
-        callingCount++;
-      }
-    };
-
-    Task task = new SimpleTask();
-
-    assertEquals("Initial calling count of 0", new Integer(0), callingCount);
-
-    task.executeWith(callback);
-
-    assertEquals("Callback called once", new Integer(1), callingCount);
-
-    task.executeWith(callback);
-
-    assertEquals("Callback called twice", new Integer(2), callingCount);
-
+		String[] args = {};
+		App.main(args);
 	}
 }

chain/index.md

@@ -4,10 +4,7 @@ title: Chain of responsibility
 folder: chain
 permalink: /patterns/chain/
 categories: Behavioral
-tags:
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+tags: Java
 ---
 
 **Intent:** Avoid coupling the sender of a request to its receiver by giving
@@ -26,7 +23,3 @@ objects and pass the request along the chain until an object handles it.
 
 * [java.util.logging.Logger#log()](http://docs.oracle.com/javase/8/docs/api/java/util/logging/Logger.html#log%28java.util.logging.Level,%20java.lang.String%29)
 * [Apache Commons Chain](https://commons.apache.org/proper/commons-chain/index.html)
-
-**Credits**
-
-* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)

chain/pom.xml

@@ -1,11 +1,12 @@
 <?xml version="1.0"?>
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-    <version>1.9.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>chain</artifactId>
 	<dependencies>

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

@@ -2,29 +2,24 @@ package com.iluwatar.chain;
 
 /**
  * 
- * The Chain of Responsibility pattern is a design pattern consisting of command objects and a
- * series of processing objects. Each processing object contains logic that defines the types of
- * command objects that it can handle; the rest are passed to the next processing object in the
- * chain. A mechanism also exists for adding new processing objects to the end of this chain.
- * <p>
- * In this example we organize the request handlers ({@link RequestHandler}) into a chain where each
- * handler has a chance to act on the request on its turn. Here the king ({@link OrcKing}) makes
- * requests and the military orcs ({@link OrcCommander}, {@link OrcOfficer}, {@link OrcSoldier})
- * form the handler chain.
+ * Chain of Responsibility organizes request handlers ({@link RequestHandler}) into a
+ * chain where each handler has a chance to act on the request on its turn. In
+ * this example the king ({@link OrcKing}) makes requests and the military orcs
+ * ({@link OrcCommander}, {@link OrcOfficer}, {@link OrcSoldier}) form the handler chain.
  * 
  */
 public class App {
 
 	/**
 	 * Program entry point
-   * 
 	 * @param args command line args
 	 */
 	public static void main(String[] args) {
 
 		OrcKing king = new OrcKing();
 		king.makeRequest(new Request(RequestType.DEFEND_CASTLE, "defend castle"));
-    king.makeRequest(new Request(RequestType.TORTURE_PRISONER, "torture prisoner"));
+		king.makeRequest(new Request(RequestType.TORTURE_PRISONER,
+				"torture prisoner"));
 		king.makeRequest(new Request(RequestType.COLLECT_TAX, "collect tax"));
 
 	}

chain/src/main/java/com/iluwatar/chain/OrcCommander.java

@@ -15,7 +15,6 @@ public class OrcCommander extends RequestHandler {
 	public void handleRequest(Request req) {
 		if (req.getRequestType().equals(RequestType.DEFEND_CASTLE)) {
 			printHandling(req);
-      req.markHandled();
 		} else {
 			super.handleRequest(req);
 		}

chain/src/main/java/com/iluwatar/chain/OrcOfficer.java

@@ -15,7 +15,6 @@ public class OrcOfficer extends RequestHandler {
 	public void handleRequest(Request req) {
 		if (req.getRequestType().equals(RequestType.TORTURE_PRISONER)) {
 			printHandling(req);
-      req.markHandled();
 		} else {
 			super.handleRequest(req);
 		}

chain/src/main/java/com/iluwatar/chain/OrcSoldier.java

@@ -15,7 +15,6 @@ public class OrcSoldier extends RequestHandler {
 	public void handleRequest(Request req) {
 		if (req.getRequestType().equals(RequestType.COLLECT_TAX)) {
 			printHandling(req);
-      req.markHandled();
 		} else {
 			super.handleRequest(req);
 		}

chain/src/main/java/com/iluwatar/chain/Request.java

@@ -1,78 +1,38 @@
 package com.iluwatar.chain;
 
-import java.util.Objects;
-
 /**
+ * 
  * Request
+ *
  */
 public class Request {
 
-  /**
-   * The type of this request, used by each item in the chain to see if they should or can handle
-   * this particular request
-   */
-  private final RequestType requestType;
+	private String requestDescription;
+	private RequestType requestType;
 
-  /**
-   * A description of the request
-   */
-  private final String requestDescription;
-
-  /**
-   * Indicates if the request is handled or not. A request can only switch state from unhandled to
-   * handled, there's no way to 'unhandle' a request
-   */
-  private boolean handled = false;
-
-  /**
-   * Create a new request of the given type and accompanied description.
-   *
-   * @param requestType        The type of request
-   * @param requestDescription The description of the request
-   */
-  public Request(final RequestType requestType, final String requestDescription) {
-    this.requestType = Objects.requireNonNull(requestType);
-    this.requestDescription = Objects.requireNonNull(requestDescription);
+	public Request(RequestType requestType, String requestDescription) {
+		this.setRequestType(requestType);
+		this.setRequestDescription(requestDescription);
 	}
 
-  /**
-   * Get a description of the request
-   *
-   * @return A human readable description of the request
-   */
 	public String getRequestDescription() {
 		return requestDescription;
 	}
 
-  /**
-   * Get the type of this request, used by each person in the chain of command to see if they should
-   * or can handle this particular request
-   *
-   * @return The request type
-   */
+	public void setRequestDescription(String requestDescription) {
+		this.requestDescription = requestDescription;
+	}
+
 	public RequestType getRequestType() {
 		return requestType;
 	}
 
-  /**
-   * Mark the request as handled
-   */
-  public void markHandled() {
-    this.handled = true;
-  }
-
-  /**
-   * Indicates if this request is handled or not
-   *
-   * @return <tt>true</tt> when the request is handled, <tt>false</tt> if not
-   */
-  public boolean isHandled() {
-    return this.handled;
+	public void setRequestType(RequestType requestType) {
+		this.requestType = requestType;
 	}
 
 	@Override
 	public String toString() {
 		return getRequestDescription();
 	}
-
 }

chain/src/main/java/com/iluwatar/chain/RequestHandler.java

@@ -13,9 +13,6 @@ public abstract class RequestHandler {
 		this.next = next;
 	}
 
-  /**
-   * Request handler
-   */
 	public void handleRequest(Request req) {
 		if (next != null) {
 			next.handleRequest(req);

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

@@ -2,6 +2,8 @@ package com.iluwatar.chain;
 
 import org.junit.Test;
 
+import com.iluwatar.chain.App;
+
 /**
  * 
  * Application test

chain/src/test/java/com/iluwatar/chain/OrcKingTest.java

@@ -1,37 +0,0 @@
-package com.iluwatar.chain;
-
-import org.junit.Test;
-
-import static org.junit.Assert.assertTrue;
-
-/**
- * Date: 12/6/15 - 9:29 PM
- *
- * @author Jeroen Meulemeester
- */
-public class OrcKingTest {
-
-  /**
-   * All possible requests
-   */
-  private static final Request[] REQUESTS = new Request[]{
-      new Request(RequestType.DEFEND_CASTLE, "Don't let the barbarians enter my castle!!"),
-      new Request(RequestType.TORTURE_PRISONER, "Don't just stand there, tickle him!"),
-      new Request(RequestType.COLLECT_TAX, "Don't steal, the King hates competition ..."),
-  };
-
-  @Test
-  public void testMakeRequest() throws Exception {
-    final OrcKing king = new OrcKing();
-
-    for (final Request request : REQUESTS) {
-      king.makeRequest(request);
-      assertTrue(
-          "Expected all requests from King to be handled, but [" + request + "] was not!",
-          request.isHandled()
-      );
-    }
-
-  }
-
-}

checkstyle-suppressions.xml

@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE suppressions PUBLIC "-//Puppy Crawl//DTD Suppressions 1.1//EN"
-    "http://www.puppycrawl.com/dtds/suppressions_1_1.dtd">
-<suppressions>
-   <suppress checks="AvoidStarImport" files="[\\/]src[\\/]test[\\/]java[\\/]"/>
-   <suppress checks="[a-zA-Z0-9]*" files="[\\/]src[\\/]test[\\/]resources[\\/]"/>
-   <suppress checks="[a-zA-Z0-9]*" files="[\\/]build[\\/]generated-sources[\\/]"/>
-   <suppress checks="[a-zA-Z0-9]*" files="[\\/]src[\\/]main[\\/]resources[\\/]"/>
-</suppressions>

checkstyle.xml

@@ -26,9 +26,7 @@
 <module name="Checker">
     <property name="charset" value="UTF-8"/>
 
-	<property name="fileExtensions" value="java, xml, properties"/>
-
-    <property name="severity" value="error"/>
+    <property name="severity" value="warning"/>
 
     <!-- Checks for whitespace                               -->
     <!-- See http://checkstyle.sf.net/config_whitespace.html -->
@@ -50,7 +48,7 @@
             <property name="allowNonPrintableEscapes" value="true"/>
         </module>
         <module name="LineLength">
-            <property name="max" value="120"/>
+            <property name="max" value="100"/>
             <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
         </module>
         <module name="AvoidStarImport"/>
@@ -63,7 +61,7 @@
         </module>
         <module name="NeedBraces"/>
         <module name="LeftCurly">
-            <property name="maxLineLength" value="120"/>
+            <property name="maxLineLength" value="100"/>
         </module>
         <module name="RightCurly"/>
         <module name="RightCurly">
@@ -88,6 +86,9 @@
         <module name="FallThrough"/>
         <module name="UpperEll"/>
         <module name="ModifierOrder"/>
+        <module name="EmptyLineSeparator">
+            <property name="allowNoEmptyLineBetweenFields" value="true"/>
+        </module>
         <module name="SeparatorWrap">
             <property name="tokens" value="DOT"/>
             <property name="option" value="nl"/>
@@ -96,19 +97,42 @@
             <property name="tokens" value="COMMA"/>
             <property name="option" value="EOL"/>
         </module>
-		
-        <!-- Checks for Naming Conventions.                  -->
-        <!-- See http://checkstyle.sf.net/config_naming.html -->
-        <module name="ConstantName"/>
-        <module name="LocalFinalVariableName"/>
-        <module name="LocalVariableName"/>
-        <module name="MemberName"/>
-        <module name="MethodName"/>
-        <module name="PackageName"/>
-        <module name="ParameterName"/>
-        <module name="StaticVariableName"/>
-        <module name="TypeName"/>
-
+        <module name="PackageName">
+            <property name="format" value="^[a-z]+(\.[a-z][a-z0-9]*)*$"/>
+            <message key="name.invalidPattern"
+                     value="Package name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="TypeName">
+            <message key="name.invalidPattern"
+                     value="Type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="MemberName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+            <message key="name.invalidPattern"
+                     value="Member name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="ParameterName">
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+            <message key="name.invalidPattern"
+                     value="Parameter name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="LocalVariableName">
+            <property name="tokens" value="VARIABLE_DEF"/>
+            <property name="format" value="^[a-z][a-z0-9][a-zA-Z0-9]*$"/>
+            <property name="allowOneCharVarInForLoop" value="true"/>
+            <message key="name.invalidPattern"
+                     value="Local variable name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="ClassTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Class type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
+        <module name="MethodTypeParameterName">
+            <property name="format" value="(^[A-Z][0-9]?)$|([A-Z][a-zA-Z0-9]*[T]$)"/>
+            <message key="name.invalidPattern"
+                     value="Method type name ''{0}'' must match pattern ''{1}''."/>
+        </module>
         <module name="NoFinalizer"/>
         <module name="GenericWhitespace">
             <message key="ws.followed"
@@ -133,6 +157,14 @@
             <property name="allowedAbbreviationLength" value="1"/>
         </module>
         <module name="OverloadMethodsDeclarationOrder"/>
+        <module name="VariableDeclarationUsageDistance"/>
+        <module name="CustomImportOrder">
+            <property name="thirdPartyPackageRegExp" value=".*"/>
+            <property name="specialImportsRegExp" value="com.google"/>
+            <property name="sortImportsInGroupAlphabetically" value="true"/>
+            <property name="customImportOrderRules"
+                      value="STATIC###SPECIAL_IMPORTS###THIRD_PARTY_PACKAGE###STANDARD_JAVA_PACKAGE"/>
+        </module>
         <module name="MethodParamPad"/>
         <module name="OperatorWrap">
             <property name="option" value="NL"/>
@@ -148,6 +180,11 @@
         </module>
         <module name="NonEmptyAtclauseDescription"/>
         <module name="JavadocTagContinuationIndentation"/>
+        <module name="SummaryJavadocCheck">
+            <property name="forbiddenSummaryFragments"
+                      value="^@return the *|^This method returns |^A [{]@code [a-zA-Z0-9]+[}]( is a )"/>
+        </module>
+        <module name="JavadocParagraph"/>
         <module name="AtclauseOrder">
             <property name="tagOrder" value="@param, @return, @throws, @deprecated"/>
             <property name="target" value="CLASS_DEF, INTERFACE_DEF, ENUM_DEF, METHOD_DEF, CTOR_DEF, VARIABLE_DEF"/>
@@ -158,7 +195,7 @@
             <property name="allowMissingThrowsTags" value="true"/>
             <property name="allowMissingReturnTag" value="true"/>
             <property name="minLineCount" value="2"/>
-            <property name="allowedAnnotations" value="Override, Test, Before, After, Parameters, Given, When, BeforeClass, AfterClass, Parameterized"/>
+            <property name="allowedAnnotations" value="Override, Test"/>
             <property name="allowThrowsTagsForSubclasses" value="true"/>
         </module>
         <module name="MethodName">
@@ -168,5 +205,4 @@
         </module>
         <module name="SingleLineJavadoc"/>
     </module>
-
 </module>

command/index.md

@@ -4,14 +4,9 @@ title: Command
 folder: command
 permalink: /patterns/command/
 categories: Behavioral
-tags: 
- - Java
- - Gang Of Four
- - Difficulty-Intermediate
+tags: Java
 ---
 
-**Also known as:** Action, Transaction
-
 **Intent:** Encapsulate a request as an object, thereby letting you
 parameterize clients with different requests, queue or log requests, and
 support undoable operations.
@@ -35,7 +30,3 @@ support undoable operations.
 **Real world examples:**
 
 * [java.lang.Runnable](http://docs.oracle.com/javase/8/docs/api/java/lang/Runnable.html)
-
-**Credits**
-
-* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)

command/pom.xml

@@ -1,11 +1,12 @@
 <?xml version="1.0"?>
-<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
 	<modelVersion>4.0.0</modelVersion>
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-    <version>1.9.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>command</artifactId>
 	<dependencies>
@@ -14,10 +15,5 @@
 			<artifactId>junit</artifactId>
 			<scope>test</scope>
 		</dependency>
-    <dependency>
-      <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
-      <scope>test</scope>
-    </dependency>
 	</dependencies>
 </project>

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

@@ -2,22 +2,19 @@ package com.iluwatar.command;
 
 /**
  * 
- * The Command pattern is a behavioral design pattern in which an object is used to encapsulate all
- * information needed to perform an action or trigger an event at a later time. This information
- * includes the method name, the object that owns the method and values for the method parameters.
+ * In Command pattern actions are objects that can be executed and undone. 
  * <p>
- * Four terms always associated with the command pattern are command, receiver, invoker and client.
- * A command object (spell) knows about the receiver (target) and invokes a method of the receiver.
- * Values for parameters of the receiver method are stored in the command. The receiver then does
- * the work. An invoker object (wizard) knows how to execute a command, and optionally does
- * bookkeeping about the command execution. The invoker does not know anything about a concrete
- * command, it knows only about command interface. Both an invoker object and several command
- * objects are held by a client object (app). The client decides which commands to execute at which
- * points. To execute a command, it passes the command object to the invoker object.
+ * Four terms always associated with the command pattern are command, receiver, invoker and client. A command 
+ * object (spell) knows about the receiver (target) and invokes a method of the receiver. Values for parameters of 
+ * the receiver method are stored in the command. The receiver then does the work. An invoker object (wizard) 
+ * knows how to execute a command, and optionally does bookkeeping about the command execution. The invoker 
+ * does not know anything about a concrete command, it knows only about command interface. Both an invoker object 
+ * and several command objects are held by a client object (app). The client decides which commands to execute at 
+ * which points. To execute a command, it passes the command object to the invoker object.
  * <p>
- * In other words, in this example the wizard casts spells on the goblin. The wizard keeps track of
- * the previous spells cast, so it is easy to undo them. In addition, the wizard keeps track of the
- * spells undone, so they can be redone.
+ * In other words, in this example the wizard casts spells on the goblin. The wizard keeps track of the previous
+ * spells cast, so it is easy to undo them. In addition, the wizard keeps track of the spells undone, so they
+ * can be redone.
  * 
  * 
  */
@@ -25,7 +22,6 @@ public class App {
 
 	/**
 	 * Program entry point
-   * 
 	 * @param args command line args
 	 */
 	public static void main(String[] args) {

command/src/main/java/com/iluwatar/command/Target.java

@@ -30,12 +30,9 @@ public abstract class Target {
 	@Override
 	public abstract String toString();
 
-  /**
-   * Print status
-   */
 	public void printStatus() {
-    System.out.println(String.format("%s, [size=%s] [visibility=%s]", this, getSize(),
-        getVisibility()));
+		System.out.println(String.format("%s, [size=%s] [visibility=%s]", this,
+				getSize(), getVisibility()));
 		System.out.println();
 	}
 }

command/src/main/java/com/iluwatar/command/Wizard.java

@@ -13,20 +13,15 @@ public class Wizard {
 	private Deque<Command> undoStack = new LinkedList<>();
 	private Deque<Command> redoStack = new LinkedList<>();
 
-  public Wizard() {}
+	public Wizard() {
+	}
 
-  /**
-   * Cast spell
-   */
 	public void castSpell(Command command, Target target) {
 		System.out.println(this + " casts " + command + " at " + target);
 		command.execute(target);
 		undoStack.offerLast(command);
 	}
 
-  /**
-   * Undo last spell
-   */
 	public void undoLastSpell() {
 		if (!undoStack.isEmpty()) {
 			Command previousSpell = undoStack.pollLast();
@@ -36,9 +31,6 @@ public class Wizard {
 		}
 	}
 
-  /**
-   * Redo last spell
-   */
 	public void redoLastSpell() {
 		if (!redoStack.isEmpty()) {
 			Command previousSpell = redoStack.pollLast();