Move urm plugin configuration to parent pom.xml

.travis.yml

@@ -1,18 +1,20 @@
 language: java
+
 jdk:
-- oraclejdk8
+  - 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
+  - "export DISPLAY=:99.0"
-- sh -e /etc/init.d/xvfb start
+  - "sh -e /etc/init.d/xvfb start"
   
 after_success:
-- mvn clean test jacoco:report coveralls:report
+  - mvn clean test jacoco:report coveralls:report
-- bash update-ghpages.sh
+  - 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 
-
-

README.md

@@ -26,13 +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,
+Once you are familiar with these concepts you can start drilling down into patterns by any of the following approaches
-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
 
  - Using difficulty tags, `Difficulty-Beginner`, `Difficulty-Intermediate` & `Difficulty-Expert`.
  - Using pattern categories, `Creational`, `Behavioral` and others.
@@ -44,6 +38,7 @@ If you are willing to contribute to the project you will find the relevant infor
 
 # 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)
@@ -53,6 +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

@@ -4,13 +4,9 @@ title: Abstract Factory
 folder: abstract-factory
 permalink: /patterns/abstract-factory/
 categories: Creational
-tags: 
+tags: Java
- - Java
- - Gang Of Four
 ---
 
-**Also known as:** Kit
-
 **Intent:** Provide an interface for creating families of related or dependent
 objects without specifying their concrete classes.
 
@@ -26,7 +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"
+<project
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	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>1.8.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>abstract-factory</artifactId>
 	<dependencies>

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

@@ -3,18 +3,12 @@ package com.iluwatar.abstractfactory;
 
 /**
  * 
- * The Abstract Factory pattern provides a way to encapsulate a group of individual factories that
+ * The essence of the Abstract Factory pattern is a factory interface
- * have a common theme without specifying their concrete classes. In normal usage, the client
+ * ({@link KingdomFactory}) and its implementations ({@link ElfKingdomFactory},
- * software creates a concrete implementation of the abstract factory and then uses the generic
+ * {@link OrcKingdomFactory}).
- * interface of the factory to create the concrete objects that are part of the theme. The client
- * does not know (or care) which concrete objects it gets from each of these internal factories,
- * since it uses only the generic interfaces of their products. This pattern separates the details
- * of implementation of a set of objects from their general usage and relies on object composition,
- * as object creation is implemented in methods exposed in the factory interface.
  * <p>
- * The essence of the Abstract Factory pattern is a factory interface ({@link KingdomFactory}) and
+ * The example uses both concrete implementations to create a king, a castle and
- * its implementations ({@link ElfKingdomFactory}, {@link OrcKingdomFactory}). The example uses both
+ * an army.
- * concrete implementations to create a king, a castle and an army.
  * 
  */
 public class App {
@@ -23,10 +17,8 @@ public class App {
 	private Castle castle;
 	private Army army;
 
-
 	/**
 	 * Creates kingdom
-   * 
 	 * @param factory
 	 */
 	public void createKingdom(final KingdomFactory factory) {
@@ -78,33 +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/OrcKing.java

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

abstract-factory/src/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/index.md

@@ -4,13 +4,9 @@ title: Adapter
 folder: adapter
 permalink: /patterns/adapter/
 categories: Structural
-tags:
+tags: Java
- - Java
- - Gang Of Four
 ---
 
-**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.
@@ -26,7 +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"
+<project
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	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>1.8.0</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

@@ -1,28 +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.
  * 
- * <p>There are two variations of the Adapter pattern: The class adapter implements the adaptee's
+ * There are two variations of the Adapter pattern: The class adapter implements
- * interface whereas the object adapter uses composition to contain the adaptee in the adapter
+ * the adaptee's interface whereas the object adapter uses composition to
- * object. This example uses the object adapter approach.
+ * contain the adaptee in the adapter object. This example uses the object
+ * adapter approach.
+ * <p>
+ * The Adapter ({@link GnomeEngineer}) converts the interface of the target class
+ * ({@link GoblinGlider}) into a suitable one expected by the client
+ * ({@link GnomeEngineeringManager}).
  * 
- * <p>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) {
-    Engineer manager = new GnomeEngineeringManager(new GnomeEngineer());
+		Engineer manager = new GnomeEngineeringManager();
 		manager.operateDevice();
 	}
 }

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

@@ -8,4 +8,5 @@ package com.iluwatar.adapter;
 public interface Engineer {
 
 	void operateDevice();
+
 }

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

@@ -2,8 +2,8 @@ package com.iluwatar.adapter;
 
 /**
  * 
- * Adapter class. Adapts the interface of the device ({@link GoblinGlider}) into {@link Engineer}
+ * Adapter class. Adapts the interface of the device ({@link GoblinGlider}) into
- * interface expected by the client ({@link GnomeEngineeringManager}).
+ * {@link Engineer} interface expected by the client ({@link GnomeEngineeringManager}).
  * 
  */
 public class GnomeEngineer implements Engineer {
@@ -20,4 +20,5 @@ public class GnomeEngineer implements Engineer {
 		glider.gainSpeed();
 		glider.takeOff();
 	}
+
 }

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

@@ -1,26 +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();
-  }
-
-  public GnomeEngineeringManager(Engineer engineer) {
-    this.engineer = engineer;
 	}
 
 	@Override
 	public void operateDevice() {
 		engineer.operateDevice();
 	}
-
-  public void setEngineer(Engineer engineer) {
-    this.engineer = engineer;
-  }
 }

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

@@ -1,68 +0,0 @@
-package com.iluwatar.adapter;
-
-import static org.mockito.Mockito.spy;
-import static org.mockito.Mockito.verify;
-
-import java.util.HashMap;
-import java.util.Map;
-
-import org.junit.Before;
-import org.junit.Test;
-
-/**
- * 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.
- * 
- * <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 GnomeEngineer}) converts the interface 
- * of the target class ({@link GoblinGlider}) into a suitable one expected by 
- * the client ({@link GnomeEngineeringManager}
- * ).
- */
-public class AdapterPatternTest {
-
-  private Map<String, Object> beans;
-
-  private static final String ENGINEER_BEAN = "engineer";
-
-  private static final String MANAGER_BEAN = "manager";
-
-  /**
-   * This method runs before the test execution and sets the bean objects in the beans Map.
-   */
-  @Before
-  public void setup() {
-    beans = new HashMap<>();
-
-    GnomeEngineer gnomeEngineer = spy(new GnomeEngineer());
-    beans.put(ENGINEER_BEAN, gnomeEngineer);
-
-    GnomeEngineeringManager manager = new GnomeEngineeringManager();
-    manager.setEngineer((GnomeEngineer) beans.get(ENGINEER_BEAN));
-    beans.put(MANAGER_BEAN, manager);
-  }
-
-  /**
-   * This test asserts that when we call operateDevice() method on a manager bean, it is internally
-   * calling operateDevice method on the engineer object. The Adapter ({@link GnomeEngineer})
-   * converts the interface of the target class ( {@link GoblinGlider}) into a suitable one expected
-   * by the client ({@link GnomeEngineeringManager} ).
-   */
-  @Test
-  public void testAdapter() {
-    Engineer manager = (Engineer) beans.get(MANAGER_BEAN);
-
-    // when manager is asked to operate device
-    manager.operateDevice();
-
-    // Manager internally calls the engineer object to operateDevice
-    Engineer engineer = (Engineer) beans.get(ENGINEER_BEAN);
-    verify(engineer).operateDevice();
-  }
-}

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/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"
+<project
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	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>1.8.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>async-method-invocation</artifactId>
 	<dependencies>

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

@@ -4,24 +4,23 @@ 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
+ * <code>AsyncResult</code> which is an intermediate container for an asynchronously evaluated value,
- * value, <code>AsyncCallback</code> which can be provided to be executed on task completion and
+ * <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
+ * The main method shows example flow of async invocations. The main thread starts multiple tasks with
- * with variable durations and then continues its own work. When the main thread has done it's job
+ * variable durations and then continues its own work. When the main thread has done it's job it collects
- * it collects the results of the async tasks. Two of the tasks are handled with callbacks, meaning
+ * the results of the async tasks. Two of the tasks are handled with callbacks, meaning the callbacks are
- * the callbacks are executed immediately when the tasks complete.
+ * executed immediately when the tasks complete.
  * <p>
- * Noteworthy difference of thread usage between the async results and callbacks is that the async
+ * Noteworthy difference of thread usage between the async results and callbacks is that the async results
- * results are collected in the main thread but the callbacks are executed within the worker
+ * are collected in the main thread but the callbacks are executed within the worker threads. This should be
- * threads. This should be noted when working with thread pools.
+ * noted when working with thread pools.
  * <p>
- * Java provides its own implementations of async method invocation pattern. FutureTask,
+ * Java provides its own implementations of async method invocation pattern. FutureTask, CompletableFuture
- * CompletableFuture and ExecutorService are the real world implementations of this pattern. But due
+ * and ExecutorService are the real world implementations of this pattern. But due to the nature of parallel
- * to the nature of parallel programming, the implementations are not trivial. This example does not
+ * programming, the implementations are not trivial. This example does not take all possible scenarios into
- * take all possible scenarios into account but rather provides a simple version that helps to
+ * account but rather provides a simple version that helps to understand the pattern.
- * understand the pattern.
  *
  * @see AsyncResult
  * @see AsyncCallback
@@ -41,10 +40,8 @@ public class App {
 		AsyncResult<Integer> asyncResult1 = executor.startProcess(lazyval(10, 500));
 		AsyncResult<String> asyncResult2 = executor.startProcess(lazyval("test", 300));
 		AsyncResult<Long> asyncResult3 = executor.startProcess(lazyval(50L, 700));
-    AsyncResult<Integer> asyncResult4 =
+		AsyncResult<Integer> asyncResult4 = executor.startProcess(lazyval(20, 400), callback("Callback result 4"));
-        executor.startProcess(lazyval(20, 400), callback("Callback result 4"));
+		AsyncResult<String> asyncResult5 = executor.startProcess(lazyval("callback", 600), callback("Callback result 5"));
-    AsyncResult<String> asyncResult5 =
-        executor.startProcess(lazyval("callback", 600), callback("Callback result 5"));
 
 		// emulate processing in the current thread while async tasks are running in their own threads
 		Thread.sleep(350); // Oh boy I'm working hard here

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/ThreadAsyncExecutor.java

@@ -34,8 +34,7 @@ public class ThreadAsyncExecutor implements AsyncExecutor {
 	}
 
 	@Override
-  public <T> T endProcess(AsyncResult<T> asyncResult) throws ExecutionException,
+	public <T> T endProcess(AsyncResult<T> asyncResult) throws ExecutionException, InterruptedException {
-      InterruptedException {
 		if (asyncResult.isCompleted()) {
 			return asyncResult.getValue();
 		} else {
@@ -45,8 +44,8 @@ public class ThreadAsyncExecutor implements AsyncExecutor {
 	}
 
 	/**
-   * Simple implementation of async result that allows completing it successfully with a value or
+	 * Simple implementation of async result that allows completing it successfully with a value
-   * exceptionally with an exception. A really simplified version from its real life cousins
+	 * or exceptionally with an exception. A really simplified version from its real life cousins
 	 * FutureTask and CompletableFuture.
 	 *
 	 * @see java.util.concurrent.FutureTask
@@ -71,8 +70,8 @@ public class ThreadAsyncExecutor implements AsyncExecutor {
 		}
 
 		/**
-     * Sets the value from successful execution and executes callback if available. Notifies any
+		 * Sets the value from successful execution and executes callback if available. Notifies
-     * thread waiting for completion.
+		 * any thread waiting for completion.
 		 *
 		 * @param value value of the evaluated task
 		 */
@@ -86,8 +85,8 @@ public class ThreadAsyncExecutor implements AsyncExecutor {
 		}
 
 		/**
-     * Sets the exception from failed execution and executes callback if available. Notifies any
+		 * Sets the exception from failed execution and executes callback if available. Notifies
-     * thread waiting for completion.
+		 * any thread waiting for completion.
 		 *
 		 * @param exception exception of the failed task
 		 */

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);
 	}
+
 }

bridge/index.md

@@ -4,13 +4,9 @@ title: Bridge
 folder: bridge
 permalink: /patterns/bridge/
 categories: Structural
-tags:
+tags: Java
- - Java
- - Gang Of Four
 ---
 
-**Also known as:** Handle/Body
-
 **Intent:** Decouple an abstraction from its implementation so that the two can
 vary independently.
 
@@ -24,7 +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"
+<project
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	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>1.8.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>bridge</artifactId>
 	<dependencies>

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
+ * In Bridge pattern both abstraction ({@link MagicWeapon}) and implementation
- * decouple an abstraction from its implementation so that the two can vary independently.
+ * ({@link MagicWeaponImpl}) have their own class hierarchies. The interface of the
- * <p>
+ * 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");
 	}
+
 }

builder/index.md

@@ -4,9 +4,7 @@ title: Builder
 folder: builder
 permalink: /patterns/builder/
 categories: Creational
-tags:
+tags: Java
- - Java
- - Gang Of Four
 ---
 
 **Intent:** Separate the construction of a complex object from its
@@ -24,7 +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"
+<project
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	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>1.8.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>builder</artifactId>
 	<dependencies>

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

@@ -1,54 +1,41 @@
 package com.iluwatar.builder;
 
-import com.iluwatar.builder.Hero.HeroBuilder;
+import com.iluwatar. builder.Hero.HeroBuilder;
 
 /**
  * 
- * The intention of the Builder pattern is to find a solution to the telescoping constructor
+ * This is the Builder pattern variation as described by Joshua Bloch in
- * anti-pattern. The telescoping constructor anti-pattern occurs when the increase of object
+ * Effective Java 2nd Edition.
- * 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.
  * <p>
- * The Builder pattern has another benefit. It can be used for objects that contain flat data (html
+ * We want to build {@link Hero} objects, but its construction is complex because of the
- * code, SQL query, X.509 certificate...), that is to say, data that can't be easily edited. This
+ * many parameters needed. To aid the user we introduce {@link HeroBuilder} class.
- * type of data cannot be edited step by step and must be edited at once. The best way to construct
+ * {@link HeroBuilder} takes the minimum parameters to build {@link Hero} object in its
- * such an object is to use a builder class.
+ * constructor. After that additional configuration for the {@link Hero} object can be
- * <p>
+ * done using the fluent {@link HeroBuilder} interface. When configuration is ready the
- * In this example we have the Builder pattern variation as described by Joshua Bloch in Effective
+ * build method is called to receive the final {@link Hero} object.
- * 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.
  * 
  */
 public class App {
 
 	/**
 	 * Program entry point
-   * 
 	 * @param args command line args
 	 */
 	public static void main(String[] args) {
 
-    Hero mage =
+		Hero mage = new HeroBuilder(Profession.MAGE, "Riobard")
-        new HeroBuilder(Profession.MAGE, "Riobard").withHairColor(HairColor.BLACK)
+				.withHairColor(HairColor.BLACK).withWeapon(Weapon.DAGGER)
-            .withWeapon(Weapon.DAGGER).build();
+				.build();
 		System.out.println(mage);
 
-    Hero warrior =
+		Hero warrior = new HeroBuilder(Profession.WARRIOR, "Amberjill")
-        new HeroBuilder(Profession.WARRIOR, "Amberjill").withHairColor(HairColor.BLOND)
+				.withHairColor(HairColor.BLOND)
-            .withHairType(HairType.LONG_CURLY).withArmor(Armor.CHAIN_MAIL).withWeapon(Weapon.SWORD)
+				.withHairType(HairType.LONG_CURLY).withArmor(Armor.CHAIN_MAIL)
-            .build();
+				.withWeapon(Weapon.SWORD).build();
 		System.out.println(warrior);
 
-    Hero thief =
+		Hero thief = new HeroBuilder(Profession.THIEF, "Desmond")
-        new HeroBuilder(Profession.THIEF, "Desmond").withHairType(HairType.BALD)
+				.withHairType(HairType.BALD).withWeapon(Weapon.BOW).build();
-            .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(
+	BALD("bald"), SHORT("short"), CURLY("curly"), LONG_STRAIGHT("long straight"), LONG_CURLY("long curly");
-      "long curly");
 
     private String title;
 

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

@@ -95,7 +95,8 @@ public class Hero {
 
 		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

@@ -2,7 +2,7 @@ package com.iluwatar.builder;
 
 import org.junit.Test;
 
-import com.iluwatar.builder.App;
+import com.iluwatar. builder.App;
 
 /**
  * 

business-delegate/pom.xml

@@ -6,7 +6,7 @@
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-		<version>1.8.0</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
+ * The Business Delegate pattern adds an abstraction layer between the presentation and business tiers.
- * retrieved through service lookups. The Business Delegate itself may contain business logic too
+ * By using the pattern we gain loose coupling between the tiers. The Business Delegate encapsulates
- * potentially tying together multiple service calls, exception handling, retrying etc.
+ * 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

@@ -1,24 +0,0 @@
----
-layout: pattern
-title: Caching
-folder: caching
-permalink: /patterns/caching/
-categories: Other
-tags:
- - Java
----
-
-**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>1.8.0</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());
-    userAccount1 = AppManager.find("001");
-    userAccount1 = 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());
-    userAccount2 = AppManager.find("002");
-    System.out.println(AppManager.printCacheContent());
-    userAccount2 = AppManager.find("002");
-    userAccount2.setUserName("Jane G.");
-    AppManager.save(userAccount2);
-    System.out.println(AppManager.printCacheContent());
-    userAccount2 = AppManager.find("002");
-    System.out.println(AppManager.printCacheContent());
-    userAccount2 = 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());
-    userAccount3 = 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());
-    userAccount4 = AppManager.find("004");
-    System.out.println(AppManager.printCacheContent());
-  }
-}

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

@@ -1,75 +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;
-
-  /**
-   *
-   * 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();
-    }
-  }
-
-  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);
-  }
-
-  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;
-  }
-
-  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

@@ -1,104 +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;
-
-  public static void initCapacity(int capacity) {
-    if (null == cache)
-      cache = new LRUCache(capacity);
-    else
-      cache.setCapacity(capacity);
-  }
-
-  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;
-  }
-
-  public static void writeThrough(UserAccount userAccount) {
-    if (cache.contains(userAccount.getUserID())) {
-      DBManager.updateDB(userAccount);
-    } else {
-      DBManager.writeToDB(userAccount);
-    }
-    cache.set(userAccount.getUserID(), userAccount);
-  }
-
-  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);
-    }
-  }
-
-  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;
-  }
-
-  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);
-  }
-
-  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);
-    }
-  }
-
-  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

@@ -1,123 +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;
-
-  public static void createVirtualDB() {
-    useMongoDB = false;
-    virtualDB = new HashMap<String, UserAccount>();
-  }
-
-  public static void connect() throws ParseException {
-    useMongoDB = true;
-    mongoClient = new MongoClient();
-    db = mongoClient.getDatabase("test");
-  }
-
-  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;
-  }
-
-  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()));
-  }
-
-  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

@@ -1,146 +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;
-  }
-
-  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;
-  }
-
-  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);
-  }
-
-  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;
-  }
-
-  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;
-  }
-
-  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

@@ -1,47 +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;
-
-  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/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"
+<project
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	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>1.8.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>callback</artifactId>
 	<dependencies>

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

@@ -2,9 +2,8 @@ package com.iluwatar.callback;
 
 /**
  * 
- * Callback pattern is more native for functional languages where functions are treated as
+ * Callback pattern is more native for functional languages where functions are treated as first-class citizens.
- * first-class citizens. Prior to Java 8 callbacks can be simulated using simple (alike command)
+ * Prior to Java 8 callbacks can be simulated using simple (alike command) interfaces.
- * interfaces.
  * 
  */
 public class App {

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/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() {
+		String[] args = {};
-      @Override
+		App.main(args);
-      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);
-
 	}
 }

chain/index.md

@@ -4,9 +4,7 @@ title: Chain of responsibility
 folder: chain
 permalink: /patterns/chain/
 categories: Behavioral
-tags:
+tags: Java
- - Java
- - Gang Of Four
 ---
 
 **Intent:** Avoid coupling the sender of a request to its receiver by giving
@@ -25,7 +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"
+<project
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	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>1.8.0</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
+ * Chain of Responsibility organizes request handlers ({@link RequestHandler}) into a
- * series of processing objects. Each processing object contains logic that defines the types of
+ * chain where each handler has a chance to act on the request on its turn. In
- * command objects that it can handle; the rest are passed to the next processing object in the
+ * this example the king ({@link OrcKing}) makes requests and the military orcs
- * chain. A mechanism also exists for adding new processing objects to the end of this chain.
+ * ({@link OrcCommander}, {@link OrcOfficer}, {@link OrcSoldier}) form the handler 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.
  * 
  */
 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"));
 
 	}

command/index.md

@@ -4,13 +4,9 @@ title: Command
 folder: command
 permalink: /patterns/command/
 categories: Behavioral
-tags: 
+tags: Java
- - Java
- - Gang Of Four
 ---
 
-**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.
@@ -34,7 +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"
+<project
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	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>1.8.0</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
+ * In Command pattern actions are objects that can be executed and undone. 
- * 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.
  * <p>
- * Four terms always associated with the command pattern are command, receiver, invoker and client.
+ * Four terms always associated with the command pattern are command, receiver, invoker and client. A command 
- * A command object (spell) knows about the receiver (target) and invokes a method of the receiver.
+ * object (spell) knows about the receiver (target) and invokes a method of the receiver. Values for parameters of 
- * Values for parameters of the receiver method are stored in the command. The receiver then does
+ * the receiver method are stored in the command. The receiver then does the work. An invoker object (wizard) 
- * the work. An invoker object (wizard) knows how to execute a command, and optionally does
+ * knows how to execute a command, and optionally does bookkeeping about the command execution. The invoker 
- * bookkeeping about the command execution. The invoker does not know anything about a concrete
+ * does not know anything about a concrete command, it knows only about command interface. Both an invoker object 
- * command, it knows only about command interface. Both an invoker object and several command
+ * and several command objects are held by a client object (app). The client decides which commands to execute at 
- * objects are held by a client object (app). The client decides which commands to execute at which
+ * which points. To execute a command, it passes the command object to the invoker object.
- * 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
+ * In other words, in this example the wizard casts spells on the goblin. The wizard keeps track of the previous
- * the previous spells cast, so it is easy to undo them. In addition, the wizard keeps track of the
+ * spells cast, so it is easy to undo them. In addition, the wizard keeps track of the spells undone, so they
- * spells undone, so they can be redone.
+ * 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

@@ -31,8 +31,8 @@ public abstract class Target {
 	public abstract String toString();
 
 	public void printStatus() {
-    System.out.println(String.format("%s, [size=%s] [visibility=%s]", this, getSize(),
+		System.out.println(String.format("%s, [size=%s] [visibility=%s]", this,
-        getVisibility()));
+				getSize(), getVisibility()));
 		System.out.println();
 	}
 }

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

@@ -13,7 +13,8 @@ public class Wizard {
 	private Deque<Command> undoStack = new LinkedList<>();
 	private Deque<Command> redoStack = new LinkedList<>();
 
-  public Wizard() {}
+	public Wizard() {
+	}
 
 	public void castSpell(Command command, Target target) {
 		System.out.println(this + " casts " + command + " at " + target);

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

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

command/src/test/java/com/iluwatar/command/CommandTest.java

@@ -1,71 +0,0 @@
-package com.iluwatar.command;
-
-import static org.junit.Assert.assertEquals;
-
-import org.junit.Test;
-
-/**
- * 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.
- * 
- * <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.
- */
-public class CommandTest {
-
-  private static final String GOBLIN = "Goblin";
-
-  /**
-   * This test verifies that when 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, it also verifies that the
-   * wizard keeps track of the spells undone, so they can be redone.
-   */
-  @Test
-  public void testCommand() {
-
-    Wizard wizard = new Wizard();
-    Goblin goblin = new Goblin();
-
-    wizard.castSpell(new ShrinkSpell(), goblin);
-    verifyGoblin(goblin, GOBLIN, Size.SMALL, Visibility.VISIBLE);
-
-    wizard.castSpell(new InvisibilitySpell(), goblin);
-    verifyGoblin(goblin, GOBLIN, Size.SMALL, Visibility.INVISIBLE);
-
-    wizard.undoLastSpell();
-    verifyGoblin(goblin, GOBLIN, Size.SMALL, Visibility.VISIBLE);
-
-    wizard.undoLastSpell();
-    verifyGoblin(goblin, GOBLIN, Size.NORMAL, Visibility.VISIBLE);
-
-    wizard.redoLastSpell();
-    verifyGoblin(goblin, GOBLIN, Size.SMALL, Visibility.VISIBLE);
-
-    wizard.redoLastSpell();
-    verifyGoblin(goblin, GOBLIN, Size.SMALL, Visibility.INVISIBLE);
-  }
-
-  /**
-   * This method asserts that the passed goblin object has the name as expectedName, size as
-   * expectedSize and visibility as expectedVisibility.
-   *
-   * @param goblin a goblin object whose state is to be verified against other parameters
-   * @param expectedName expectedName of the goblin
-   * @param expectedSize expected size of the goblin
-   * @param expectedVisibilty exepcted visibility of the goblin
-   */
-  private void verifyGoblin(Goblin goblin, String expectedName, Size expectedSize,
-      Visibility expectedVisibilty) {
-    assertEquals("Goblin's name must be same as expectedName", expectedName, goblin.toString());
-    assertEquals("Goblin's size must be same as expectedSize", expectedSize, goblin.getSize());
-    assertEquals("Goblin's visibility must be same as expectedVisibility", expectedVisibilty,
-        goblin.getVisibility());
-  }
-}

composite/index.md

@@ -4,9 +4,7 @@ title: Composite
 folder: composite
 permalink: /patterns/composite/
 categories: Structural
-tags:
+tags: Java
- - Java
- - Gang Of Four
 ---
 
 **Intent:** Compose objects into tree structures to represent part-whole
@@ -24,7 +22,3 @@ of objects uniformly.
 
 * [java.awt.Container](http://docs.oracle.com/javase/8/docs/api/java/awt/Container.html) and [java.awt.Component](http://docs.oracle.com/javase/8/docs/api/java/awt/Component.html)
 * [Apache Wicket](https://github.com/apache/wicket) component tree, see [Component](https://github.com/apache/wicket/blob/91e154702ab1ff3481ef6cbb04c6044814b7e130/wicket-core/src/main/java/org/apache/wicket/Component.java) and [MarkupContainer](https://github.com/apache/wicket/blob/b60ec64d0b50a611a9549809c9ab216f0ffa3ae3/wicket-core/src/main/java/org/apache/wicket/MarkupContainer.java)
-
-**Credits**
-
-* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)

composite/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"
+<project
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	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>1.8.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>composite</artifactId>
 	<dependencies>

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

@@ -1,21 +1,16 @@
 package com.iluwatar.composite;
 
 /**
- * The Composite pattern is a partitioning design pattern. The Composite pattern describes that a
+ * 
- * group of objects is to be treated in the same way as a single instance of an object. The intent
+ * With Composite we can treat tree hierarchies of objects with uniform
- * of a composite is to "compose" objects into tree structures to represent part-whole hierarchies.
+ * interface ({@link LetterComposite}). In this example we have sentences composed of
- * Implementing the Composite pattern lets clients treat individual objects and compositions
+ * words composed of letters.
- * uniformly.
- * <p>
- * In this example we have sentences composed of words composed of letters. All of the objects can
- * be treated through the same interface ({@link LetterComposite}).
  * 
  */
 public class App {
 
 	/**
 	 * Program entry point
-   * 
 	 * @param args command line args
 	 */
 	public static void main(String[] args) {

composite/src/main/java/com/iluwatar/composite/Letter.java

@@ -22,4 +22,5 @@ public class Letter extends LetterComposite {
 	protected void printThisAfter() {
 		// nop
 	}
+
 }

composite/src/main/java/com/iluwatar/composite/Messenger.java

@@ -15,19 +15,20 @@ public class Messenger {
 
 		List<Word> words = new ArrayList<Word>();
 
-    words.add(new Word(Arrays.asList(new Letter('W'), new Letter('h'), new Letter('e'), new Letter(
+		words.add(new Word(Arrays.asList(new Letter('W'), new Letter('h'),
-        'r'), new Letter('e'))));
+				new Letter('e'), new Letter('r'), new Letter('e'))));
-    words.add(new Word(Arrays.asList(new Letter('t'), new Letter('h'), new Letter('e'), new Letter(
+		words.add(new Word(Arrays.asList(new Letter('t'), new Letter('h'),
-        'r'), new Letter('e'))));
+				new Letter('e'), new Letter('r'), new Letter('e'))));
 		words.add(new Word(Arrays.asList(new Letter('i'), new Letter('s'))));
 		words.add(new Word(Arrays.asList(new Letter('a'))));
-    words.add(new Word(Arrays.asList(new Letter('w'), new Letter('h'), new Letter('i'), new Letter(
+		words.add(new Word(Arrays.asList(new Letter('w'), new Letter('h'),
-        'p'))));
+				new Letter('i'), new Letter('p'))));
-    words.add(new Word(Arrays.asList(new Letter('t'), new Letter('h'), new Letter('e'), new Letter(
+		words.add(new Word(Arrays.asList(new Letter('t'), new Letter('h'),
-        'r'), new Letter('e'))));
+				new Letter('e'), new Letter('r'), new Letter('e'))));
 		words.add(new Word(Arrays.asList(new Letter('i'), new Letter('s'))));
 		words.add(new Word(Arrays.asList(new Letter('a'))));
-    words.add(new Word(Arrays.asList(new Letter('w'), new Letter('a'), new Letter('y'))));
+		words.add(new Word(Arrays.asList(new Letter('w'), new Letter('a'),
+				new Letter('y'))));
 
 		return new Sentence(words);
 
@@ -37,18 +38,18 @@ public class Messenger {
 
 		List<Word> words = new ArrayList<Word>();
 
-    words.add(new Word(Arrays.asList(new Letter('M'), new Letter('u'), new Letter('c'), new Letter(
+		words.add(new Word(Arrays.asList(new Letter('M'), new Letter('u'),
-        'h'))));
+				new Letter('c'), new Letter('h'))));
-    words.add(new Word(Arrays.asList(new Letter('w'), new Letter('i'), new Letter('n'), new Letter(
+		words.add(new Word(Arrays.asList(new Letter('w'), new Letter('i'),
-        'd'))));
+				new Letter('n'), new Letter('d'))));
-    words.add(new Word(Arrays.asList(new Letter('p'), new Letter('o'), new Letter('u'), new Letter(
+		words.add(new Word(Arrays.asList(new Letter('p'), new Letter('o'),
-        'r'), new Letter('s'))));
+				new Letter('u'), new Letter('r'), new Letter('s'))));
-    words.add(new Word(Arrays.asList(new Letter('f'), new Letter('r'), new Letter('o'), new Letter(
+		words.add(new Word(Arrays.asList(new Letter('f'), new Letter('r'),
-        'm'))));
+				new Letter('o'), new Letter('m'))));
-    words.add(new Word(Arrays.asList(new Letter('y'), new Letter('o'), new Letter('u'), new Letter(
+		words.add(new Word(Arrays.asList(new Letter('y'), new Letter('o'),
-        'r'))));
+				new Letter('u'), new Letter('r'))));
-    words.add(new Word(Arrays.asList(new Letter('m'), new Letter('o'), new Letter('u'), new Letter(
+		words.add(new Word(Arrays.asList(new Letter('m'), new Letter('o'),
-        't'), new Letter('h'))));
+				new Letter('u'), new Letter('t'), new Letter('h'))));
 
 		return new Sentence(words);
 

composite/src/main/java/com/iluwatar/composite/Sentence.java

@@ -24,4 +24,5 @@ public class Sentence extends LetterComposite {
 	protected void printThisAfter() {
 		System.out.print(".");
 	}
+
 }

composite/src/main/java/com/iluwatar/composite/Word.java

@@ -24,4 +24,5 @@ public class Word extends LetterComposite {
 	protected void printThisAfter() {
 		// nop
 	}
+
 }

dao/index.md

@@ -4,9 +4,7 @@ title: Data Access Object
 folder: dao
 permalink: /patterns/dao/
 categories: Architectural
-tags:
+tags: Java
- - Java
- - Difficulty-Beginner
 ---
 
 **Intent:** Object provides an abstract interface to some type of database or
@@ -18,7 +16,3 @@ other persistence mechanism.
 
 * when you want to consolidate how the data layer is accessed
 * when you want to avoid writing multiple data retrieval/persistence layers
-
-**Credits:**
-
-* [J2EE Design Patterns](http://www.amazon.com/J2EE-Design-Patterns-William-Crawford/dp/0596004273/ref=sr_1_2)

dao/pom.xml

@@ -6,64 +6,14 @@
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-    <version>1.8.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>dao</artifactId>
-
 	<dependencies>
 		<dependency>
 			<groupId>junit</groupId>
 			<artifactId>junit</artifactId>
 			<scope>test</scope>
 		</dependency>
-    <dependency>
-      <groupId>log4j</groupId>
-      <artifactId>log4j</artifactId>
-    </dependency>
 	</dependencies>
-
-  <build>
-
-    <!-- 
-    log4j.xml file will be copied both in ${project.build.outputDirectory} 
-    and ${project.build.directory}. Thanks to Sean Patrick Floyd 
-    (http://stackoverflow.com/questions/5637532/maven-how-to-place-resource-file-together-with-jar) 
-    -->
-      
-    <resources>
-      <resource> <!-- regular processing for every resource file -->
-        <directory>src/main/resources</directory>
-      </resource>
-      <resource> <!-- processing with a different output directory for log4j.xml -->
-        <directory>src/main/resources</directory>
-        <includes>
-          <include>log4j.xml</include>
-        </includes>
-        <targetPath>..</targetPath> <!-- relative to target/classes i.e. ${project.build.directory} -->
-      </resource>
-    </resources>
-
-    <plugins>
-
-      <!-- 
-      This will exclude log4j.xml file from generated JAR 
-      -->
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-jar-plugin</artifactId>
-        <version>2.6</version>
-        <configuration>
-          <excludes>
-            <exclude>log4j.xml</exclude>
-          </excludes>
-          <archive>
-            <manifest>
-              <addClasspath>true</addClasspath>
-            </manifest>
-          </archive>
-        </configuration>
-      </plugin>
-
-    </plugins>
-  </build>
 </project>

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

@@ -3,56 +3,51 @@ package com.iluwatar.dao;
 import java.util.ArrayList;
 import java.util.List;
 
-import org.apache.log4j.Logger;
-
 /**
  * 
- * Data Access Object (DAO) is an object that provides an abstract interface to some type of
+ * With the DAO pattern, we can use various method calls to retrieve/add/delete/update data without directly
- * database or other persistence mechanism. By mapping application calls to the persistence layer,
+ * interacting with the data. The below example demonstrates basic operations(CRUD): select, add, update, and delete.
- * DAO provide some specific data operations without exposing details of the database. This
- * isolation supports the Single responsibility principle. It separates what data accesses the
- * application needs, in terms of domain-specific objects and data types (the public interface of
- * the DAO), from how these needs can be satisfied with a specific DBMS.
- * <p>
- * With the DAO pattern, we can use various method calls to retrieve/add/delete/update data without
- * directly interacting with the data. The below example demonstrates basic CRUD operations: select,
- * add, update, and delete.
  * 
  */
 public class App {
 
-  private static Logger LOGGER = Logger.getLogger(App.class);
-
 	/**
-   * Program entry point.
+	 * Program entry point
-   * 
+	 * @param args command line args
-   * @param args command line args.
 	 */
-  public static void main(final String[] args) {
+	public static void main(String[] args) {
-    final CustomerDaoImpl customerDao = new CustomerDaoImpl(generateSampleCustomers());
+
-    LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
+		CustomerDaoImpl customerDao = new CustomerDaoImpl(generateSampleCustomers());
-    LOGGER.info("customerDao.getCusterById(2): " + customerDao.getCustomerById(2));
+
-    final Customer customer = new Customer(4, "Dan", "Danson");
+		System.out.println("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
+		System.out.println("customerDao.getCusterById(2): " + customerDao.getCusterById(2));
+
+		Customer customer = new Customer(4, "Dan", "Danson");
 		customerDao.addCustomer(customer);
-    LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
+
+		System.out.println("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
+
 		customer.setFirstName("Daniel");
 		customer.setLastName("Danielson");
 		customerDao.updateCustomer(customer);
-    LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
+
+		System.out.println("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
+
 		customerDao.deleteCustomer(customer);
-    LOGGER.info("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
+
+		System.out.println("customerDao.getAllCustomers(): " + customerDao.getAllCustomers());
 	}
 
 	/**
-   * Generate customers.
+	 * Generate customers
-   * 
+	 * @return list of customers
-   * @return list of customers.
 	 */
 	public static List<Customer> generateSampleCustomers() {
-    final Customer customer1 = new Customer(1, "Adam", "Adamson");
+		Customer customer1 = new Customer(1, "Adam", "Adamson");
-    final Customer customer2 = new Customer(2, "Bob", "Bobson");
+		Customer customer2 = new Customer(2, "Bob", "Bobson");
-    final Customer customer3 = new Customer(3, "Carl", "Carlson");
+		Customer customer3 = new Customer(3, "Carl", "Carlson");
-    final List<Customer> customers = new ArrayList<Customer>();
+
+		List<Customer> customers = new ArrayList<Customer>();
 		customers.add(customer1);
 		customers.add(customer2);
 		customers.add(customer3);

dao/src/main/java/com/iluwatar/dao/Customer.java

@@ -11,7 +11,7 @@ public class Customer {
     private String firstName;
     private String lastName;
 
-  public Customer(final int id, final String firstName, final String lastName) {
+    public Customer(int id, String firstName, String lastName) {
         this.id = id;
         this.firstName = firstName;
         this.lastName = lastName;
@@ -21,7 +21,7 @@ public class Customer {
         return id;
     }
 
-  public void setId(final int id) {
+    public void setId(int id) {
         this.id = id;
     }
 
@@ -29,7 +29,7 @@ public class Customer {
         return firstName;
     }
 
-  public void setFirstName(final String firstName) {
+    public void setFirstName(String firstName) {
         this.firstName = firstName;
     }
 
@@ -37,32 +37,34 @@ public class Customer {
         return lastName;
     }
 
-  public void setLastName(final String lastName) {
+    public void setLastName(String lastName) {
         this.lastName = lastName;
     }
 
     @Override
     public String toString() {
-    return "Customer{" + "id=" + getId() + ", firstName='" + getFirstName() + '\'' + ", lastName='"
+        return "Customer{" +
-        + getLastName() + '\'' + '}';
+                "id=" + id +
+                ", firstName='" + firstName + '\'' +
+                ", lastName='" + lastName + '\'' +
+                '}';
     }
 
     @Override
-  public boolean equals(final Object o) {
+    public boolean equals(Object o) {
-    boolean isEqual = false;
+        if (this == o) return true;
-    if (this == o) {
+        if (o == null || getClass() != o.getClass()) return false;
-      isEqual = true;
+
-    } else if (o != null && (getClass() == o.getClass())) {
+        Customer customer = (Customer) o;
-      final Customer customer = (Customer) o;
+
-      if (getId() == customer.getId())
+        if (id != customer.id) return false;
-        isEqual = true;
+
-    }
+        return true;
-    return isEqual;
     }
 
     @Override
     public int hashCode() {
-    int result = getId();
+        int result = id;
         return result;
     }
 }

dao/src/main/java/com/iluwatar/dao/CustomerDao.java

@@ -9,13 +9,9 @@ import java.util.List;
  */
 public interface CustomerDao {
 	
-  List<Customer> getAllCustomers();
+    public List<Customer> getAllCustomers();
-
+    public Customer getCusterById(int id);
-  Customer getCustomerById(int id);
+    public void addCustomer(Customer customer);
-
+    public void updateCustomer(Customer customer);
-  void addCustomer(Customer customer);
+    public void deleteCustomer(Customer customer);
-
-  void updateCustomer(Customer customer);
-
-  void deleteCustomer(Customer customer);
 }

dao/src/main/java/com/iluwatar/dao/CustomerDaoImpl.java

@@ -4,12 +4,11 @@ import java.util.List;
 
 /**
  * 
- * The data access object (DAO) is an object that provides an abstract interface to some type of
+ * The data access object (DAO) is an object that provides an abstract interface to some type of database or other persistence mechanism.
- * database or other persistence mechanism. By mapping application calls to the persistence layer,
+ * By mapping application calls to the persistence layer, DAO provide some specific data operations without exposing details of the database.
- * DAO provide some specific data operations without exposing details of the database. This
+ * This isolation supports the Single responsibility principle. It separates what data accesses the application needs, in terms of
- * isolation supports the Single responsibility principle. It separates what data accesses the
+ * domain-specific objects and data types (the public interface of the DAO), from how these needs can be satisfied with a specific DBMS,
- * application needs, in terms of domain-specific objects and data types (the public interface of
+ * database schema, etc.
- * the DAO), from how these needs can be satisfied with a specific DBMS, database schema, etc.
  * 
  */
 public class CustomerDaoImpl implements CustomerDao {
@@ -18,7 +17,7 @@ public class CustomerDaoImpl implements CustomerDao {
     // Note: Normally this would be in the form of an actual database and not part of the Dao Impl.
     private List<Customer> customers;
 
-  public CustomerDaoImpl(final List<Customer> customers) {
+    public CustomerDaoImpl(List<Customer> customers) {
         this.customers = customers;
     }
 
@@ -28,35 +27,31 @@ public class CustomerDaoImpl implements CustomerDao {
     }
 
     @Override
-  public Customer getCustomerById(final int id) {
+    public Customer getCusterById(int id) {
-    Customer customer = null;
+        for (int i = 0; i < customers.size(); i++) {
-    for (final Customer cus : getAllCustomers()) {
+            if (customers.get(i).getId() == id) {
-      if (cus.getId() == id) {
+                return customers.get(i);
-        customer = cus;
-        break;
             }
         }
-    return customer;
+        // No customer found
+        return null;
     }
 
     @Override
-  public void addCustomer(final Customer customer) {
+    public void addCustomer(Customer customer) {
-    if (getCustomerById(customer.getId()) == null) {
         customers.add(customer);
     }
-  }
 
 
     @Override
-  public void updateCustomer(final Customer customer) {
+    public void updateCustomer(Customer customer) {
-    if (getAllCustomers().contains(customer)) {
+        if (customers.contains(customer)) {
-      final int index = getAllCustomers().indexOf(customer);
+            customers.set(customers.indexOf(customer), customer);
-      getAllCustomers().set(index, customer);
         }
     }
 
     @Override
-  public void deleteCustomer(final Customer customer) {
+    public void deleteCustomer(Customer customer) {
-    getAllCustomers().remove(customer);
+        customers.remove(customer);
     }
 }

dao/src/main/resources/log4j.xml

@@ -1,17 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" ?>
-<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
-<log4j:configuration debug="true"
-	xmlns:log4j='http://jakarta.apache.org/log4j/'>
-
-	<appender name="console" class="org.apache.log4j.ConsoleAppender">
-		<layout class="org.apache.log4j.PatternLayout">
-			<param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n" />
-		</layout>
-	</appender>
-
-	<root>
-		<level value="INFO" />
-		<appender-ref ref="console" />
-	</root>
-
-</log4j:configuration>

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

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

dao/src/test/java/com/iluwatar/dao/CustomerDaoImplTest.java

@@ -1,99 +0,0 @@
-package com.iluwatar.dao;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertTrue;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import org.junit.Before;
-import org.junit.Test;
-
-public class CustomerDaoImplTest {
-
-  private CustomerDaoImpl impl;
-  private List<Customer> customers;
-  private static final Customer CUSTOMER = new Customer(1, "Freddy", "Krueger");
-
-  @Before
-  public void setUp() {
-    customers = new ArrayList<Customer>();
-    customers.add(CUSTOMER);
-    impl = new CustomerDaoImpl(customers);
-  }
-
-  @Test
-  public void deleteExistingCustomer() {
-    assertEquals(1, impl.getAllCustomers().size());
-    impl.deleteCustomer(CUSTOMER);
-    assertTrue(impl.getAllCustomers().isEmpty());
-  }
-
-  @Test
-  public void deleteNonExistingCustomer() {
-    final Customer nonExistingCustomer = new Customer(2, "Robert", "Englund");
-    impl.deleteCustomer(nonExistingCustomer);
-    assertEquals(1, impl.getAllCustomers().size());
-  }
-
-  @Test
-  public void updateExistingCustomer() {
-    final String newFirstname = "Bernard";
-    final String newLastname = "Montgomery";
-    final Customer customer = new Customer(CUSTOMER.getId(), newFirstname, newLastname);
-    impl.updateCustomer(customer);
-    final Customer cust = impl.getCustomerById(CUSTOMER.getId());
-    assertEquals(newFirstname, cust.getFirstName());
-    assertEquals(newLastname, cust.getLastName());
-  }
-
-  @Test
-  public void updateNonExistingCustomer() {
-    final int nonExistingId = getNonExistingCustomerId();
-    final String newFirstname = "Douglas";
-    final String newLastname = "MacArthur";
-    final Customer customer = new Customer(nonExistingId, newFirstname, newLastname);
-    impl.updateCustomer(customer);
-    assertNull(impl.getCustomerById(nonExistingId));
-    final Customer existingCustomer = impl.getCustomerById(CUSTOMER.getId());
-    assertEquals(CUSTOMER.getFirstName(), existingCustomer.getFirstName());
-    assertEquals(CUSTOMER.getLastName(), existingCustomer.getLastName());
-  }
-
-  @Test
-  public void addCustomer() {
-    final Customer newCustomer = new Customer(3, "George", "Patton");
-    impl.addCustomer(newCustomer);
-    assertEquals(2, impl.getAllCustomers().size());
-  }
-
-  @Test
-  public void addAlreadyAddedCustomer() {
-    final Customer newCustomer = new Customer(3, "George", "Patton");
-    impl.addCustomer(newCustomer);
-    assertEquals(2, impl.getAllCustomers().size());
-    impl.addCustomer(newCustomer);
-    assertEquals(2, impl.getAllCustomers().size());
-  }
-
-  @Test
-  public void getExistinCustomerById() {
-    assertEquals(CUSTOMER, impl.getCustomerById(CUSTOMER.getId()));
-  }
-
-  @Test
-  public void getNonExistinCustomerById() {
-    final int nonExistingId = getNonExistingCustomerId();
-    assertNull(impl.getCustomerById(nonExistingId));
-  }
-
-  /**
-   * An arbitrary number which does not correspond to an active Customer id.
-   * 
-   * @return an int of a customer id which doesn't exist
-   */
-  private int getNonExistingCustomerId() {
-    return 999;
-  }
-}

dao/src/test/java/com/iluwatar/dao/CustomerTest.java

@@ -1,74 +0,0 @@
-package com.iluwatar.dao;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotEquals;
-
-import org.junit.Before;
-import org.junit.Test;
-
-public class CustomerTest {
-
-  private Customer customer;
-  private static final int ID = 1;
-  private static final String FIRSTNAME = "Winston";
-  private static final String LASTNAME = "Churchill";
-
-  @Before
-  public void setUp() {
-    customer = new Customer(ID, FIRSTNAME, LASTNAME);
-  }
-
-  @Test
-  public void getAndSetId() {
-    final int newId = 2;
-    customer.setId(newId);
-    assertEquals(newId, customer.getId());
-  }
-
-  @Test
-  public void getAndSetFirstname() {
-    final String newFirstname = "Bill";
-    customer.setFirstName(newFirstname);
-    assertEquals(newFirstname, customer.getFirstName());
-  }
-
-  @Test
-  public void getAndSetLastname() {
-    final String newLastname = "Clinton";
-    customer.setLastName(newLastname);
-    assertEquals(newLastname, customer.getLastName());
-  }
-
-  @Test
-  public void notEqualWithDifferentId() {
-    final int newId = 2;
-    final Customer otherCustomer = new Customer(newId, FIRSTNAME, LASTNAME);
-    assertNotEquals(customer, otherCustomer);
-    assertNotEquals(customer.hashCode(), otherCustomer.hashCode());
-  }
-
-  @Test
-  public void equalsWithSameObjectValues() {
-    final Customer otherCustomer = new Customer(ID, FIRSTNAME, LASTNAME);
-    assertEquals(customer, otherCustomer);
-    assertEquals(customer.hashCode(), otherCustomer.hashCode());
-  }
-
-  @Test
-  public void equalsWithSameObjects() {
-    assertEquals(customer, customer);
-    assertEquals(customer.hashCode(), customer.hashCode());
-  }
-
-  @Test
-  public void testToString() {
-    final StringBuffer buffer = new StringBuffer();
-    buffer.append("Customer{id=");
-    buffer.append("" + customer.getId());
-    buffer.append(", firstName='");
-    buffer.append(customer.getFirstName());
-    buffer.append("\', lastName='");
-    buffer.append(customer.getLastName() + "\'}");
-    assertEquals(buffer.toString(), customer.toString());
-  }
-}

decorator/index.md

@@ -4,13 +4,9 @@ title: Decorator
 folder: decorator
 permalink: /patterns/decorator/
 categories: Structural
-tags:
+tags: Java
- - Java
- - Gang Of Four
 ---
 
-**Also known as:** Wrapper
-
 **Intent:** Attach additional responsibilities to an object dynamically.
 Decorators provide a flexible alternative to subclassing for extending
 functionality.
@@ -22,7 +18,3 @@ functionality.
 * to add responsibilities to individual objects dynamically and transparently, that is, without affecting other objects
 * for responsibilities that can be withdrawn
 * when extension by subclassing is impractical. Sometimes a large number of independent extensions are possible and would produce an explosion of subclasses to support every combination. Or a class definition may be hidden or otherwise unavailable for subclassing
-
-**Credits**
-
-* [Design Patterns: Elements of Reusable Object-Oriented Software](http://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612)

decorator/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"
+<project
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	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>1.8.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>decorator</artifactId>
 	<dependencies>

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

@@ -2,21 +2,18 @@ package com.iluwatar.decorator;
 
 /**
  * 
- * The Decorator pattern is a more flexible alternative to subclassing. The Decorator class
+ * Decorator pattern is a more flexible alternative to subclassing. The decorator
- * implements the same interface as the target and uses composition to "decorate" calls to the
+ * class implements the same interface as the target and uses composition to
- * target. Using the Decorator pattern it is possible to change the behavior of the class during
+ * "decorate" calls to the target.
- * runtime.
  * <p>
- * In this example we show how the simple {@link Troll} first attacks and then flees the battle.
+ * Using decorator pattern it is possible to change class behavior during
- * Then we decorate the {@link Troll} with a {@link SmartTroll} and perform the attack again. You
+ * runtime, as the example shows.
- * can see how the behavior changes after the decoration.
  * 
  */
 public class App {
 
 	/**
 	 * Program entry point
-   * 
 	 * @param args command line args
 	 */
 	public static void main(String[] args) {
@@ -26,13 +23,11 @@ public class App {
 		Hostile troll = new Troll();
 		troll.attack();
 		troll.fleeBattle();
-    System.out.printf("Simple troll power %d.\n", troll.getAttackPower());
 
 		// change the behavior of the simple troll by adding a decorator
 		System.out.println("\nA smart looking troll surprises you.");
 		Hostile smart = new SmartTroll(troll);
 		smart.attack();
 		smart.fleeBattle();
-    System.out.printf("Smart troll power %d.\n", smart.getAttackPower());
 	}
 }

decorator/src/main/java/com/iluwatar/decorator/Hostile.java

@@ -9,8 +9,6 @@ public interface Hostile {
 
 	void attack();
 
-  int getAttackPower();
-
 	void fleeBattle();
 
 }

decorator/src/main/java/com/iluwatar/decorator/SmartTroll.java

@@ -1,9 +1,10 @@
 package com.iluwatar.decorator;
 
 /**
- * SmartTroll is a decorator for {@link Hostile} objects. The calls to the {@link Hostile} interface
+ * SmartTroll is a decorator for {@link Hostile} objects.
- * are intercepted and decorated. Finally the calls are delegated to the decorated {@link Hostile}
+ * The calls to the {@link Hostile} interface are intercepted
- * object.
+ * and decorated. Finally the calls are delegated
+ * to the decorated {@link Hostile} object.
  *
  */
 public class SmartTroll implements Hostile {
@@ -20,15 +21,10 @@ public class SmartTroll implements Hostile {
 		decorated.attack();
 	}
 
-  @Override
-  public int getAttackPower() {
-    // decorated troll power + 20 because it is smart
-    return decorated.getAttackPower() + 20;
-  }
-
 	@Override
 	public void fleeBattle() {
 		System.out.println("The troll calls for help!");
 		decorated.fleeBattle();
 	}
+
 }

decorator/src/main/java/com/iluwatar/decorator/Troll.java

@@ -11,12 +11,8 @@ public class Troll implements Hostile {
 		System.out.println("The troll swings at you with a club!");
 	}
 
-  @Override
-  public int getAttackPower() {
-    return 10;
-  }
-
 	public void fleeBattle() {
 		System.out.println("The troll shrieks in horror and runs away!");
 	}
+
 }

dependency-injection/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"
+<project
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	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>1.8.0</version>
+		<version>1.6.0</version>
 	</parent>
 	<artifactId>dependency-injection</artifactId>
 	<dependencies>

dependency-injection/src/main/java/com/iluwatar/dependency/injection/AdvancedWizard.java

@@ -2,8 +2,9 @@ package com.iluwatar.dependency.injection;
 
 /**
  * 
- * AdvancedWizard implements inversion of control. It depends on abstraction that can be injected
+ * AdvancedWizard implements inversion of control.
- * through its constructor.
+ * It depends on abstraction that can be injected through
+ * its constructor.
  *
  */
 public class AdvancedWizard implements Wizard {

dependency-injection/src/main/java/com/iluwatar/dependency/injection/App.java

@@ -10,28 +10,27 @@ import com.google.inject.Injector;
  *  - High-level modules should not depend on low-level modules. Both should depend on abstractions.
  *  - Abstractions should not depend on details. Details should depend on abstractions.
  *  <p>
- * In this example we show you three different wizards. The first one ({@link SimpleWizard}) is a
+ *  In this example we show you three different wizards. The first one ({@link SimpleWizard}) is a naive 
- * naive implementation violating the inversion of control principle. It depends directly on a
+ *  implementation violating the inversion of control principle. It depends directly on a concrete
- * concrete implementation which cannot be changed.
+ *  implementation which cannot be changed.
  *  <p>
- * The second wizard ({@link AdvancedWizard}) is more flexible. It does not depend on any concrete
+ *  The second wizard ({@link AdvancedWizard}) is more flexible. It does not depend on any concrete implementation 
- * implementation but abstraction. It utilizes Dependency Injection pattern allowing its
+ *  but abstraction. It utilizes Dependency Injection pattern allowing its {@link Tobacco} dependency to be
- * {@link Tobacco} dependency to be injected through its constructor. This way, handling the
+ *  injected through its constructor. This way, handling the dependency is no longer the wizard's
- * dependency is no longer the wizard's responsibility. It is resolved outside the wizard class.
+ *  responsibility. It is resolved outside the wizard class.
  *  <p>
- * The third example takes the pattern a step further. It uses Guice framework for Dependency
+ *  The third example takes the pattern a step further. It uses Guice framework for Dependency Injection.
- * Injection. {@link TobaccoModule} binds a concrete implementation to abstraction. Injector is then
+ *  {@link TobaccoModule} binds a concrete implementation to abstraction. Injector is then used to create
- * used to create {@link GuiceWizard} object with correct dependencies.
+ *  {@link GuiceWizard} object with correct dependencies.
  *
  */
 public class App {
 	
 	/**
 	 * Program entry point
-   * 
 	 * @param args command line args
 	 */
-  public static void main(String[] args) {
+    public static void main( String[] args ) {
     	SimpleWizard simpleWizard = new SimpleWizard();
     	simpleWizard.smoke();
     	

dependency-injection/src/main/java/com/iluwatar/dependency/injection/GuiceWizard.java

@@ -4,8 +4,9 @@ import javax.inject.Inject;
 
 /**
  * 
- * GuiceWizard implements inversion of control. Its dependencies are injected through its
+ * GuiceWizard implements inversion of control.
- * constructor by Guice framework.
+ * Its dependencies are injected through its constructor
+ * by Guice framework.
  *
  */
 public class GuiceWizard implements Wizard {

dependency-injection/src/main/java/com/iluwatar/dependency/injection/SimpleWizard.java

@@ -2,8 +2,8 @@ package com.iluwatar.dependency.injection;
 
 /**
  * 
- * Naive Wizard implementation violating the inversion of control principle. It should depend on
+ * Naive Wizard implementation violating the inversion of control principle.
- * abstraction instead.
+ * It should depend on abstraction instead.
  *
  */
 public class SimpleWizard implements Wizard {