Set version number for monthly release

Fix #216 Repository vs DAO

CODE_COVERAGE.md

@@ -0,0 +1,13 @@
+# 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 
+
+

abstract-factory/index.md

@@ -9,6 +9,8 @@ tags:
  - Gang Of Four
 ---
 
+**Also known as:** Kit
+
 **Intent:** Provide an interface for creating families of related or dependent
 objects without specifying their concrete classes.
 

abstract-factory/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>abstract-factory</artifactId>
   <dependencies>

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

@@ -3,21 +3,18 @@ package com.iluwatar.abstractfactory;
 
 /**
  * 
- * The Abstract Factory pattern provides a way to encapsulate a group of individual 
+ * The Abstract Factory pattern provides a way to encapsulate a group of individual factories that
- * factories that have a common theme without specifying their concrete classes. In 
+ * have a common theme without specifying their concrete classes. In normal usage, the client
- * normal usage, the client software creates a concrete implementation of the abstract 
+ * software creates a concrete implementation of the abstract factory and then uses the generic
- * factory and then uses the generic interface of the factory to create the concrete 
+ * interface of the factory to create the concrete objects that are part of the theme. The client
- * objects that are part of the theme. The client does not know (or care) which 
+ * does not know (or care) which concrete objects it gets from each of these internal factories,
- * concrete objects it gets from each of these internal factories, since it uses only 
+ * since it uses only the generic interfaces of their products. This pattern separates the details
- * the generic interfaces of their products. This pattern separates the details of 
+ * of implementation of a set of objects from their general usage and relies on object composition,
- * implementation of a set of objects from their general usage and relies on object 
+ * as object creation is implemented in methods exposed in the factory interface.
- * 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
+ * The essence of the Abstract Factory pattern is a factory interface ({@link KingdomFactory}) and
- * ({@link KingdomFactory}) and its implementations ({@link ElfKingdomFactory},
+ * its implementations ({@link ElfKingdomFactory}, {@link OrcKingdomFactory}). The example uses both
- * {@link OrcKingdomFactory}). The example uses both concrete implementations to 
+ * concrete implementations to create a king, a castle and an army.
- * create a king, a castle and an army.
  * 
  */
 public class App {
@@ -26,8 +23,10 @@ public class App {
   private Castle castle;
   private Army army;
 
+
   /**
    * Creates kingdom
+   * 
    * @param factory
    */
   public void createKingdom(final KingdomFactory factory) {
@@ -79,4 +78,33 @@ 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

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

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

@@ -1,4 +1,5 @@
 package com.iluwatar.abstractfactory;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
 

adapter/index.md

@@ -9,6 +9,8 @@ tags:
  - 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.

adapter/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>adapter</artifactId>
   <dependencies>
@@ -14,5 +14,10 @@
       <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

@@ -1,31 +1,28 @@
 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.
  * 
- * An adapter helps two incompatible interfaces to work together. This is the real 
+ * <p>There are two variations of the Adapter pattern: The class adapter implements the adaptee's
- * world definition for an adapter. Interfaces may be incompatible but the inner 
+ * interface whereas the object adapter uses composition to contain the adaptee in the adapter
- * functionality should suit the need. The Adapter design pattern allows otherwise 
+ * object. This example uses the object adapter approach.
- * 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}).
  * 
+ * <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();
+    Engineer manager = new GnomeEngineeringManager(new GnomeEngineer());
     manager.operateDevice();
   }
 }

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

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

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

@@ -1,20 +1,26 @@
 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

@@ -0,0 +1,68 @@
+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

@@ -1,19 +0,0 @@
-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

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>async-method-invocation</artifactId>
   <dependencies>

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

@@ -4,23 +4,24 @@ import java.util.concurrent.Callable;
 
 /**
  * This application demonstrates the async method invocation pattern. Key parts of the pattern are
- * <code>AsyncResult</code> which is an intermediate container for an asynchronously evaluated value,
+ * <code>AsyncResult</code> which is an intermediate container for an asynchronously evaluated
- * <code>AsyncCallback</code> which can be provided to be executed on task completion and
+ * value, <code>AsyncCallback</code> which can be provided to be executed on task completion and
  * <code>AsyncExecutor</code> that manages the execution of the async tasks.
  * <p>
- * The main method shows example flow of async invocations. The main thread starts multiple tasks with
+ * The main method shows example flow of async invocations. The main thread starts multiple tasks
- * variable durations and then continues its own work. When the main thread has done it's job it collects
+ * with variable durations and then continues its own work. When the main thread has done it's job
- * the results of the async tasks. Two of the tasks are handled with callbacks, meaning the callbacks are
+ * it collects the results of the async tasks. Two of the tasks are handled with callbacks, meaning
- * executed immediately when the tasks complete.
+ * the callbacks are executed immediately when the tasks complete.
  * <p>
- * Noteworthy difference of thread usage between the async results and callbacks is that the async results
+ * Noteworthy difference of thread usage between the async results and callbacks is that the async
- * are collected in the main thread but the callbacks are executed within the worker threads. This should be
+ * results are collected in the main thread but the callbacks are executed within the worker
- * noted when working with thread pools.
+ * threads. This should be noted when working with thread pools.
  * <p>
- * Java provides its own implementations of async method invocation pattern. FutureTask, CompletableFuture
+ * Java provides its own implementations of async method invocation pattern. FutureTask,
- * and ExecutorService are the real world implementations of this pattern. But due to the nature of parallel
+ * CompletableFuture and ExecutorService are the real world implementations of this pattern. But due
- * programming, the implementations are not trivial. This example does not take all possible scenarios into
+ * to the nature of parallel programming, the implementations are not trivial. This example does not
- * account but rather provides a simple version that helps to understand the pattern.
+ * take all possible scenarios into account but rather provides a simple version that helps to
+ * understand the pattern.
  *
  * @see AsyncResult
  * @see AsyncCallback
@@ -40,8 +41,10 @@ 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 = executor.startProcess(lazyval(20, 400), callback("Callback result 4"));
+    AsyncResult<Integer> asyncResult4 =
-		AsyncResult<String> asyncResult5 = executor.startProcess(lazyval("callback", 600), callback("Callback result 5"));
+        executor.startProcess(lazyval(20, 400), callback("Callback result 4"));
+    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

@@ -18,5 +18,4 @@ 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

@@ -38,5 +38,4 @@ 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

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

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

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

bridge/index.md

@@ -9,6 +9,8 @@ tags:
  - Gang Of Four
 ---
 
+**Also known as:** Handle/Body
+
 **Intent:** Decouple an abstraction from its implementation so that the two can
 vary independently.
 

bridge/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>bridge</artifactId>
   <dependencies>

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

@@ -2,41 +2,38 @@ package com.iluwatar.bridge;
 
 /**
  * 
- * The Bridge pattern can also be thought of as two layers of abstraction. With Bridge, 
+ * The Bridge pattern can also be thought of as two layers of abstraction. With Bridge, you can
- * you can decouple an abstraction from its implementation so that the two can vary independently.
+ * decouple an abstraction from its implementation so that the two can vary independently.
  * <p>
- * In Bridge pattern both abstraction ({@link MagicWeapon}) and implementation
+ * In Bridge pattern both abstraction ({@link MagicWeapon}) and implementation (
- * ({@link MagicWeaponImpl}) have their own class hierarchies. The interface of the
+ * {@link MagicWeaponImpl}) have their own class hierarchies. The interface of the implementations
- * implementations can be changed without affecting the clients.
+ * 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(
+    BlindingMagicWeapon blindingMagicWeapon = new BlindingMagicWeapon(new Excalibur());
-				new Excalibur());
     blindingMagicWeapon.wield();
     blindingMagicWeapon.blind();
     blindingMagicWeapon.swing();
     blindingMagicWeapon.unwield();
 
-		FlyingMagicWeapon flyingMagicWeapon = new FlyingMagicWeapon(
+    FlyingMagicWeapon flyingMagicWeapon = new FlyingMagicWeapon(new Mjollnir());
-				new Mjollnir());
     flyingMagicWeapon.wield();
     flyingMagicWeapon.fly();
     flyingMagicWeapon.swing();
     flyingMagicWeapon.unwield();
 
-		SoulEatingMagicWeapon soulEatingMagicWeapon = new SoulEatingMagicWeapon(
+    SoulEatingMagicWeapon soulEatingMagicWeapon = new SoulEatingMagicWeapon(new Stormbringer());
-				new Stormbringer());
     soulEatingMagicWeapon.wield();
     soulEatingMagicWeapon.swing();
     soulEatingMagicWeapon.eatSoul();
     soulEatingMagicWeapon.unwield();
-
   }
 }

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

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

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

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

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

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

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

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

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

builder/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>builder</artifactId>
   <dependencies>

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

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

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

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

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

@@ -95,8 +95,7 @@ public class Hero {
 
     public HeroBuilder(Profession profession, String name) {
       if (profession == null || name == null) {
-				throw new IllegalArgumentException(
+        throw new IllegalArgumentException("profession and name can not be null");
-						"profession and name can not be null");
       }
       this.profession = profession;
       this.name = name;

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

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

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

@@ -13,5 +13,4 @@ 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>1.7.0</version>
+		<version>1.8.0</version>
 	</parent>
 	<artifactId>business-delegate</artifactId>
 	<dependencies>
@@ -15,5 +15,10 @@
 			<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

@@ -1,29 +1,34 @@
 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.
  * 
- * The Business Delegate pattern adds an abstraction layer between the presentation and business tiers.
+ * <p>Some of the services the Business Delegate uses are instantiated directly, and some can be
- * By using the pattern we gain loose coupling between the tiers. The Business Delegate encapsulates
+ * retrieved through service lookups. The Business Delegate itself may contain business logic too
- * knowledge about how to locate, connect to, and interact with the business objects that make up
+ * potentially tying together multiple service calls, exception handling, retrying etc.
- * 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

@@ -1,16 +1,18 @@
 package com.iluwatar.business.delegate;
 
 /**
- * 
  * BusinessDelegate separates the presentation and business tiers
- *
  */
 public class BusinessDelegate {
 
-	private BusinessLookup lookupService = new BusinessLookup();
+    private BusinessLookup lookupService;
     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

@@ -1,17 +1,31 @@
 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 new EjbService();
+      return ejbService;
     } else {
-			return new JmsService();
+      return 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

@@ -1,19 +0,0 @@
-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

@@ -0,0 +1,78 @@
+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/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>caching</artifactId>
   <dependencies>

callback/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>callback</artifactId>
   <dependencies>

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

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

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

@@ -11,5 +11,4 @@ public class SimpleTask extends Task {
   public void execute() {
     System.out.println("Perform some important activity and after call the callback method.");
   }
-
 }

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

@@ -5,8 +5,8 @@ import org.junit.Test;
 import static org.junit.Assert.assertEquals;
 
 /**
- * Add a field as a counter. Every time the callback method is called increment this
+ * Add a field as a counter. Every time the callback method is called increment this field. Unit
- * field. Unit test checks that the field is being incremented.
+ * test checks that the field is being incremented.
  *
  * Could be done with mock objects as well where the call method call is verified.
  */

chain/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>chain</artifactId>
   <dependencies>

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

@@ -2,30 +2,29 @@ package com.iluwatar.chain;
 
 /**
  * 
- * The Chain of Responsibility pattern is a design pattern consisting of command 
+ * The Chain of Responsibility pattern is a design pattern consisting of command objects and a
- * objects and a series of processing objects. Each processing object contains 
+ * series of processing objects. Each processing object contains logic that defines the types of
- * logic that defines the types of command objects that it can handle; the rest are 
+ * command objects that it can handle; the rest are passed to the next processing object in the
- * passed to the next processing object in the chain. A mechanism also exists for 
+ * chain. A mechanism also exists for adding new processing objects to the end of this chain.
- * adding new processing objects to the end of this chain.
  * <p>
- * In this example we organize the request handlers ({@link RequestHandler}) into a
+ * In this example we organize the request handlers ({@link RequestHandler}) into a chain where each
- * chain where each handler has a chance to act on the request on its turn. Here
+ * handler has a chance to act on the request on its turn. Here the king ({@link OrcKing}) makes
- * the king ({@link OrcKing}) makes requests and the military orcs ({@link OrcCommander}, 
+ * requests and the military orcs ({@link OrcCommander}, {@link OrcOfficer}, {@link OrcSoldier})
- * {@link OrcOfficer}, {@link OrcSoldier}) form the handler chain.
+ * 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,
+    king.makeRequest(new Request(RequestType.TORTURE_PRISONER, "torture prisoner"));
-				"torture prisoner"));
     king.makeRequest(new Request(RequestType.COLLECT_TAX, "collect tax"));
 
   }

command/index.md

@@ -9,6 +9,8 @@ tags:
  - 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.

command/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>command</artifactId>
   <dependencies>
@@ -14,5 +14,10 @@
       <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

@@ -2,21 +2,22 @@ package com.iluwatar.command;
 
 /**
  * 
- * The Command pattern is a behavioral design pattern in which an object is used to encapsulate all information 
+ * The Command pattern is a behavioral design pattern in which an object is used to encapsulate all
- * needed to perform an action or trigger an event at a later time. This information includes the method name, 
+ * information needed to perform an action or trigger an event at a later time. This information
- * the object that owns the method and values for the method parameters.
+ * 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 
+ * Four terms always associated with the command pattern are command, receiver, invoker and client.
- * object (spell) knows about the receiver (target) and invokes a method of the receiver. Values for parameters of 
+ * A command object (spell) knows about the receiver (target) and invokes a method of the receiver.
- * the receiver method are stored in the command. The receiver then does the work. An invoker object (wizard) 
+ * Values for parameters of the receiver method are stored in the command. The receiver then does
- * knows how to execute a command, and optionally does bookkeeping about the command execution. The invoker 
+ * the work. An invoker object (wizard) knows how to execute a command, and optionally does
- * does not know anything about a concrete command, it knows only about command interface. Both an invoker object 
+ * bookkeeping about the command execution. The invoker does not know anything about a concrete
- * and several command objects are held by a client object (app). The client decides which commands to execute at 
+ * command, it knows only about command interface. Both an invoker object and several command
- * which points. To execute a command, it passes the command object to the invoker object.
+ * objects are held by a client object (app). The client decides which commands to execute at which
+ * points. To execute a command, it passes the command object to the invoker object.
  * <p>
- * In other words, in this example the wizard casts spells on the goblin. The wizard keeps track of the previous
+ * In other words, in this example the wizard casts spells on the goblin. The wizard keeps track of
- * spells cast, so it is easy to undo them. In addition, the wizard keeps track of the spells undone, so they
+ * the previous spells cast, so it is easy to undo them. In addition, the wizard keeps track of the
- * can be redone.
+ * spells undone, so they can be redone.
  * 
  * 
  */
@@ -24,6 +25,7 @@ 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,
+    System.out.println(String.format("%s, [size=%s] [visibility=%s]", this, getSize(),
-				getSize(), getVisibility()));
+        getVisibility()));
     System.out.println();
   }
 }

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

@@ -13,8 +13,7 @@ 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

@@ -1,19 +0,0 @@
-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

@@ -0,0 +1,71 @@
+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/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>composite</artifactId>
   <dependencies>

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

@@ -1,20 +1,21 @@
 package com.iluwatar.composite;
 
 /**
- * The Composite pattern is a partitioning design pattern. The Composite pattern 
+ * The Composite pattern is a partitioning design pattern. The Composite pattern describes that a
- * describes that a group of objects is to be treated in the same way as a single 
+ * group of objects is to be treated in the same way as a single instance of an object. The intent
- * instance of an object. The intent of a composite is to "compose" objects into 
+ * of a composite is to "compose" objects into tree structures to represent part-whole hierarchies.
- * tree structures to represent part-whole hierarchies. Implementing the Composite 
+ * Implementing the Composite pattern lets clients treat individual objects and compositions
- * pattern lets clients treat individual objects and compositions uniformly.
+ * uniformly.
  * <p>
- * In this example we have sentences composed of words composed of letters. All of
+ * In this example we have sentences composed of words composed of letters. All of the objects can
- * the objects can be treated through the same interface ({@link LetterComposite}).
+ * 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

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

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

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

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

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

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

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

dao/pom.xml

@@ -6,7 +6,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-		<version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>dao</artifactId>
 
@@ -21,4 +21,49 @@
       <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

@@ -7,14 +7,16 @@ import org.apache.log4j.Logger;
 
 /**
  * 
- * Data Access Object (DAO) is an object that provides an abstract interface to some type of database or other 
+ * Data Access Object (DAO) is an object that provides an abstract interface to some type of
- * persistence mechanism. By mapping application calls to the persistence layer, DAO provide some specific data 
+ * database or other persistence mechanism. By mapping application calls to the persistence layer,
- * operations without exposing details of the database. This isolation supports the Single responsibility principle. 
+ * DAO provide some specific data operations without exposing details of the database. This
- * It separates what data accesses the application needs, in terms of domain-specific objects and data types 
+ * isolation supports the Single responsibility principle. It separates what data accesses the
- * (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
+ * 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
+ * With the DAO pattern, we can use various method calls to retrieve/add/delete/update data without
- * interacting with the data. The below example demonstrates basic CRUD operations: select, add, update, and delete.
+ * directly interacting with the data. The below example demonstrates basic CRUD operations: select,
+ * add, update, and delete.
  * 
  */
 public class App {

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

@@ -14,7 +14,7 @@ public class CustomerDaoImplTest {
 
   private CustomerDaoImpl impl;
   private List<Customer> customers;
-  private static final Customer CUSTOMER = new Customer(1, "Freddy", "Kruger");
+  private static final Customer CUSTOMER = new Customer(1, "Freddy", "Krueger");
 
   @Before
   public void setUp() {

decorator/index.md

@@ -9,6 +9,8 @@ tags:
  - 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.

decorator/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>decorator</artifactId>
   <dependencies>

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

@@ -2,21 +2,21 @@ package com.iluwatar.decorator;
 
 /**
  * 
- * The Decorator pattern is a more flexible alternative to subclassing. The Decorator
+ * The Decorator pattern is a more flexible alternative to subclassing. The Decorator class
- * class implements the same interface as the target and uses composition to
+ * implements the same interface as the target and uses composition to "decorate" calls to the
- * "decorate" calls to the target. Using the Decorator pattern it is possible to 
+ * target. Using the Decorator pattern it is possible to change the behavior of the class during
- * change the behavior of the class during runtime.
+ * runtime.
  * <p>
- * In this example we show how the simple {@link Troll} first attacks and then
+ * In this example we show how the simple {@link Troll} first attacks and then flees the battle.
- * flees the battle. Then we decorate the {@link Troll} with a {@link SmartTroll}
+ * Then we decorate the {@link Troll} with a {@link SmartTroll} and perform the attack again. You
- * and perform the attack again. You can see how the behavior changes after the
+ * can see how the behavior changes after the decoration.
- * decoration.
  * 
  */
 public class App {
 
   /**
    * Program entry point
+   * 
    * @param args command line args
    */
   public static void main(String[] args) {

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

@@ -1,10 +1,9 @@
 package com.iluwatar.decorator;
 
 /**
- * SmartTroll is a decorator for {@link Hostile} objects.
+ * SmartTroll is a decorator for {@link Hostile} objects. The calls to the {@link Hostile} interface
- * The calls to the {@link Hostile} interface are intercepted
+ * are intercepted and decorated. Finally the calls are delegated to the decorated {@link Hostile}
- * and decorated. Finally the calls are delegated
+ * object.
- * to the decorated {@link Hostile} object.
  *
  */
 public class SmartTroll implements Hostile {
@@ -32,5 +31,4 @@ public class SmartTroll implements Hostile {
     System.out.println("The troll calls for help!");
     decorated.fleeBattle();
   }
-
 }

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

@@ -19,5 +19,4 @@ public class Troll implements Hostile {
   public void fleeBattle() {
     System.out.println("The troll shrieks in horror and runs away!");
   }
-
 }

dependency-injection/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>dependency-injection</artifactId>
   <dependencies>

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

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

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

@@ -10,27 +10,28 @@ 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 naive 
+ * In this example we show you three different wizards. The first one ({@link SimpleWizard}) is a
- *  implementation violating the inversion of control principle. It depends directly on a concrete
+ * naive implementation violating the inversion of control principle. It depends directly on a
- *  implementation which cannot be changed.
+ * concrete implementation which cannot be changed.
  * <p>
- *  The second wizard ({@link AdvancedWizard}) is more flexible. It does not depend on any concrete implementation 
+ * The second wizard ({@link AdvancedWizard}) is more flexible. It does not depend on any concrete
- *  but abstraction. It utilizes Dependency Injection pattern allowing its {@link Tobacco} dependency to be
+ * implementation but abstraction. It utilizes Dependency Injection pattern allowing its
- *  injected through its constructor. This way, handling the dependency is no longer the wizard's
+ * {@link Tobacco} dependency to be injected through its constructor. This way, handling the
- *  responsibility. It is resolved outside the wizard class.
+ * dependency is no longer the wizard's responsibility. It is resolved outside the wizard class.
  * <p>
- *  The third example takes the pattern a step further. It uses Guice framework for Dependency Injection.
+ * The third example takes the pattern a step further. It uses Guice framework for Dependency
- *  {@link TobaccoModule} binds a concrete implementation to abstraction. Injector is then used to create
+ * Injection. {@link TobaccoModule} binds a concrete implementation to abstraction. Injector is then
- *  {@link GuiceWizard} object with correct dependencies.
+ * used to create {@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

@@ -4,9 +4,8 @@ import javax.inject.Inject;
 
 /**
  * 
- * GuiceWizard implements inversion of control.
+ * GuiceWizard implements inversion of control. Its dependencies are injected through its
- * Its dependencies are injected through its constructor
+ * constructor by Guice framework.
- * 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.
+ * Naive Wizard implementation violating the inversion of control principle. It should depend on
- * It should depend on abstraction instead.
+ * abstraction instead.
  *
  */
 public class SimpleWizard implements Wizard {

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

@@ -8,6 +8,7 @@ package com.iluwatar.dependency.injection;
 public abstract class Tobacco {
 
   public void smoke(Wizard wizard) {
-		System.out.println(String.format("%s smoking %s", wizard.getClass().getSimpleName(), this.getClass().getSimpleName()));
+    System.out.println(String.format("%s smoking %s", wizard.getClass().getSimpleName(), this
+        .getClass().getSimpleName()));
   }
 }

double-checked-locking/pom.xml

@@ -3,7 +3,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>double-checked-locking</artifactId>
   <dependencies>

double-checked-locking/src/main/java/com/iluwatar/doublechecked/locking/App.java

@@ -6,21 +6,21 @@ import java.util.concurrent.TimeUnit;
 
 /**
  * 
- * Double Checked Locking is a concurrency design pattern used to reduce the overhead 
+ * Double Checked Locking is a concurrency design pattern used to reduce the overhead of acquiring a
- * of acquiring a lock by first testing the locking criterion (the "lock hint") without 
+ * lock by first testing the locking criterion (the "lock hint") without actually acquiring the
- * actually acquiring the lock. Only if the locking criterion check indicates that 
+ * lock. Only if the locking criterion check indicates that locking is required does the actual
- * locking is required does the actual locking logic proceed.
+ * locking logic proceed.
  * <p>
- * In {@link Inventory} we store the items with a given size. However, we do not store
+ * In {@link Inventory} we store the items with a given size. However, we do not store more items
- * more items than the inventory size. To address concurrent access problems we
+ * than the inventory size. To address concurrent access problems we use double checked locking to
- * use double checked locking to add item to inventory. In this method, the
+ * add item to inventory. In this method, the thread which gets the lock first adds the item.
- * thread which gets the lock first adds the item.
  * 
  */
 public class App {
 
   /**
    * Program entry point
+   * 
    * @param args command line args
    */
   public static void main(String[] args) {
@@ -28,8 +28,7 @@ public class App {
     ExecutorService executorService = Executors.newFixedThreadPool(3);
     for (int i = 0; i < 3; i++) {
       executorService.execute(() -> {
-                while (inventory.addItem(new Item()))
+        while (inventory.addItem(new Item()));
-                    ;
       });
     }
 

double-checked-locking/src/main/java/com/iluwatar/doublechecked/locking/Inventory.java

@@ -28,8 +28,7 @@ public class Inventory {
       try {
         if (items.size() < inventorySize) {
           items.add(item);
-					System.out.println(Thread.currentThread()
+          System.out.println(Thread.currentThread() + ": items.size()=" + items.size()
-							+ ": items.size()=" + items.size()
               + ", inventorySize=" + inventorySize);
           return true;
         }
@@ -39,5 +38,4 @@ public class Inventory {
     }
     return false;
   }
-
 }

double-dispatch/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>double-dispatch</artifactId>
   <dependencies>

double-dispatch/src/main/java/com/iluwatar/doubledispatch/App.java

@@ -6,20 +6,20 @@ import java.util.List;
 /**
  * 
  * When a message with a parameter is sent to an object, the resultant behaviour is defined by the
- * implementation of that method in the receiver. Sometimes the behaviour must also be determined 
+ * implementation of that method in the receiver. Sometimes the behaviour must also be determined by
- * by the type of the parameter.
+ * the type of the parameter.
  * <p>
- * One way to implement this would be to create multiple instanceof-checks for the methods parameter.
+ * One way to implement this would be to create multiple instanceof-checks for the methods
- * However, this creates a maintenance issue. When new types are added we would also need to change
+ * parameter. However, this creates a maintenance issue. When new types are added we would also need
- * the method's implementation and add a new instanceof-check. This violates the single responsibility
+ * to change the method's implementation and add a new instanceof-check. This violates the single
- * principle - a class should have only one reason to change.
+ * responsibility principle - a class should have only one reason to change.
  * <p>
  * Instead of the instanceof-checks a better way is to make another virtual call on the parameter
  * object. This way new functionality can be easily added without the need to modify existing
  * implementation (open-closed principle).
  * <p>
- * In this example we have hierarchy of objects ({@link GameObject}) that can collide to each other. Each
+ * In this example we have hierarchy of objects ({@link GameObject}) that can collide to each other.
- * object has its own coordinates which are checked against the other objects' coordinates. If
+ * Each object has its own coordinates which are checked against the other objects' coordinates. If
  * there is an overlap, then the objects collide utilizing the Double Dispatch pattern.
  *
  */
@@ -27,9 +27,10 @@ public class App {
 
   /**
    * Program entry point
+   * 
    * @param args command line args
    */
-    public static void main( String[] args ) {
+  public static void main(String[] args) {
     // initialize game objects and print their status
     List<GameObject> objects = new ArrayList<>();
     objects.add(new FlamingAsteroid(0, 0, 5, 5));
@@ -40,7 +41,10 @@ public class App {
     System.out.println("");
 
     // collision check
-    	objects.stream().forEach(o1 -> objects.stream().forEach(o2 -> { if (o1 != o2 && o1.intersectsWith(o2)) o1.collision(o2); } ));
+    objects.stream().forEach(o1 -> objects.stream().forEach(o2 -> {
+      if (o1 != o2 && o1.intersectsWith(o2))
+        o1.collision(o2);
+    }));
     System.out.println("");
 
     // output eventual object statuses

double-dispatch/src/main/java/com/iluwatar/doubledispatch/GameObject.java

@@ -2,8 +2,7 @@ package com.iluwatar.doubledispatch;
 
 /**
  * 
- * Game objects have coordinates and some
+ * Game objects have coordinates and some other status information.
- * other status information.
  *
  */
 public abstract class GameObject extends Rectangle {

double-dispatch/src/main/java/com/iluwatar/doubledispatch/Meteoroid.java

@@ -18,21 +18,25 @@ public class Meteoroid extends GameObject {
 
   @Override
   public void collisionResolve(FlamingAsteroid asteroid) {
-		System.out.println(String.format("%s hits %s.", asteroid.getClass().getSimpleName(), this.getClass().getSimpleName()));
+    System.out.println(String.format("%s hits %s.", asteroid.getClass().getSimpleName(), this
+        .getClass().getSimpleName()));
   }
 
   @Override
   public void collisionResolve(Meteoroid meteoroid) {
-		System.out.println(String.format("%s hits %s.", meteoroid.getClass().getSimpleName(), this.getClass().getSimpleName()));
+    System.out.println(String.format("%s hits %s.", meteoroid.getClass().getSimpleName(), this
+        .getClass().getSimpleName()));
   }
 
   @Override
   public void collisionResolve(SpaceStationMir mir) {
-		System.out.println(String.format("%s hits %s.", mir.getClass().getSimpleName(), this.getClass().getSimpleName()));
+    System.out.println(String.format("%s hits %s.", mir.getClass().getSimpleName(), this.getClass()
+        .getSimpleName()));
   }
 
   @Override
   public void collisionResolve(SpaceStationIss iss) {
-		System.out.println(String.format("%s hits %s.", iss.getClass().getSimpleName(), this.getClass().getSimpleName()));
+    System.out.println(String.format("%s hits %s.", iss.getClass().getSimpleName(), this.getClass()
+        .getSimpleName()));
   }
 }

double-dispatch/src/main/java/com/iluwatar/doubledispatch/Rectangle.java

@@ -2,8 +2,7 @@ package com.iluwatar.doubledispatch;
 
 /**
  * 
- * Rectangle has coordinates and can be checked for overlap against
+ * Rectangle has coordinates and can be checked for overlap against other Rectangles.
- * other Rectangles.
  *
  */
 public class Rectangle {
@@ -23,18 +22,22 @@ public class Rectangle {
   public int getLeft() {
     return left;
   }
+
   public int getTop() {
     return top;
   }
+
   public int getRight() {
     return right;
   }
+
   public int getBottom() {
     return bottom;
   }
 
   boolean intersectsWith(Rectangle r) {
-		return !(r.getLeft() > getRight() || r.getRight() < getLeft() || r.getTop() > getBottom() || r.getBottom() < getTop());
+    return !(r.getLeft() > getRight() || r.getRight() < getLeft() || r.getTop() > getBottom() || r
+        .getBottom() < getTop());
   }
 
   @Override

double-dispatch/src/main/java/com/iluwatar/doubledispatch/SpaceStationMir.java

@@ -18,34 +18,31 @@ public class SpaceStationMir extends GameObject {
 
   @Override
   public void collisionResolve(FlamingAsteroid asteroid) {
-		System.out.println(String.format("%s hits %s. %s is damaged! %s is set on fire!", 
+    System.out.println(String.format("%s hits %s. %s is damaged! %s is set on fire!", asteroid
-				asteroid.getClass().getSimpleName(), this.getClass().getSimpleName(), 
+        .getClass().getSimpleName(), this.getClass().getSimpleName(), this.getClass()
-				this.getClass().getSimpleName(), this.getClass().getSimpleName()));
+        .getSimpleName(), this.getClass().getSimpleName()));
     setDamaged(true);
     setOnFire(true);
   }
 
   @Override
   public void collisionResolve(Meteoroid meteoroid) {
-		System.out.println(String.format("%s hits %s. %s is damaged!", 
+    System.out.println(String.format("%s hits %s. %s is damaged!", meteoroid.getClass()
-				meteoroid.getClass().getSimpleName(), this.getClass().getSimpleName(), 
+        .getSimpleName(), this.getClass().getSimpleName(), this.getClass().getSimpleName()));
-				this.getClass().getSimpleName()));
     setDamaged(true);
   }
 
   @Override
   public void collisionResolve(SpaceStationMir mir) {
-		System.out.println(String.format("%s hits %s. %s is damaged!", 
+    System.out.println(String.format("%s hits %s. %s is damaged!", mir.getClass().getSimpleName(),
-				mir.getClass().getSimpleName(), this.getClass().getSimpleName(), 
+        this.getClass().getSimpleName(), this.getClass().getSimpleName()));
-				this.getClass().getSimpleName()));
     setDamaged(true);
   }
 
   @Override
   public void collisionResolve(SpaceStationIss iss) {
-		System.out.println(String.format("%s hits %s. %s is damaged!", 
+    System.out.println(String.format("%s hits %s. %s is damaged!", iss.getClass().getSimpleName(),
-				iss.getClass().getSimpleName(), this.getClass().getSimpleName(), 
+        this.getClass().getSimpleName(), this.getClass().getSimpleName()));
-				this.getClass().getSimpleName()));
     setDamaged(true);
   }
 }

double-dispatch/src/test/java/com/iluwatar/doubledispatch/RectangleTest.java

@@ -14,9 +14,9 @@ public class RectangleTest {
 
   @Test
   public void test() {
-		Assert.assertTrue(new Rectangle(0,0,1,1).intersectsWith(new Rectangle(0,0,1,1)));
+    Assert.assertTrue(new Rectangle(0, 0, 1, 1).intersectsWith(new Rectangle(0, 0, 1, 1)));
-		Assert.assertTrue(new Rectangle(0,0,1,1).intersectsWith(new Rectangle(-1,-5,7,8)));
+    Assert.assertTrue(new Rectangle(0, 0, 1, 1).intersectsWith(new Rectangle(-1, -5, 7, 8)));
-		Assert.assertFalse(new Rectangle(0,0,1,1).intersectsWith(new Rectangle(2,2,3,3)));
+    Assert.assertFalse(new Rectangle(0, 0, 1, 1).intersectsWith(new Rectangle(2, 2, 3, 3)));
-		Assert.assertFalse(new Rectangle(0,0,1,1).intersectsWith(new Rectangle(-2,-2,-1,-1)));
+    Assert.assertFalse(new Rectangle(0, 0, 1, 1).intersectsWith(new Rectangle(-2, -2, -1, -1)));
   }
 }

event-aggregator/pom.xml

@@ -4,7 +4,7 @@
 	<parent>
 		<groupId>com.iluwatar</groupId>
 		<artifactId>java-design-patterns</artifactId>
-		<version>1.7.0</version>
+		<version>1.8.0</version>
 	</parent>
 	<artifactId>event-aggregator</artifactId>
 	<dependencies>

event-aggregator/src/main/java/com/iluwatar/event/aggregator/App.java

@@ -5,22 +5,23 @@ import java.util.List;
 
 /**
  * 
- * A system with lots of objects can lead to complexities when a client wants to subscribe 
+ * A system with lots of objects can lead to complexities when a client wants to subscribe to
- * to events. The client has to find and register for each object individually, if each 
+ * events. The client has to find and register for each object individually, if each object has
- * object has multiple events then each event requires a separate subscription.
+ * multiple events then each event requires a separate subscription.
  * <p>
- * An Event Aggregator acts as a single source of events for many objects. It registers 
+ * An Event Aggregator acts as a single source of events for many objects. It registers for all the
- * for all the events of the many objects allowing clients to register with just the aggregator.
+ * events of the many objects allowing clients to register with just the aggregator.
  * <p>
  * In the example {@link LordBaelish}, {@link LordVarys} and {@link Scout} deliver events to
- * {@link KingsHand}. {@link KingsHand}, the event aggregator, then delivers the events
+ * {@link KingsHand}. {@link KingsHand}, the event aggregator, then delivers the events to
- * to {@link KingJoffrey}.
+ * {@link KingJoffrey}.
  *
  */
 public class App {
 
   /**
    * Program entry point
+   * 
    * @param args command line args
    */
   public static void main(String[] args) {
@@ -34,8 +35,8 @@ public class App {
     emitters.add(new LordVarys(kingsHand));
     emitters.add(new Scout(kingsHand));
 
-		for (Weekday day: Weekday.values()) {
+    for (Weekday day : Weekday.values()) {
-			for (EventEmitter emitter: emitters) {
+      for (EventEmitter emitter : emitters) {
         emitter.timePasses(day);
       }
     }

event-aggregator/src/main/java/com/iluwatar/event/aggregator/Event.java

@@ -7,7 +7,8 @@ package com.iluwatar.event.aggregator;
  */
 public enum Event {
 
-	STARK_SIGHTED("Stark sighted"), WARSHIPS_APPROACHING("Warships approaching"), TRAITOR_DETECTED("Traitor detected");
+  STARK_SIGHTED("Stark sighted"), WARSHIPS_APPROACHING("Warships approaching"), TRAITOR_DETECTED(
+      "Traitor detected");
 
   private String description;
 

event-aggregator/src/main/java/com/iluwatar/event/aggregator/EventEmitter.java

@@ -26,7 +26,7 @@ public abstract class EventEmitter {
   }
 
   protected void notifyObservers(Event e) {
-		for (EventObserver obs: observers) {
+    for (EventObserver obs : observers) {
       obs.onEvent(e);
     }
   }

event-aggregator/src/main/java/com/iluwatar/event/aggregator/KingsHand.java

@@ -2,8 +2,7 @@ package com.iluwatar.event.aggregator;
 
 /**
  * 
- * KingsHand observes events from multiple sources and delivers them
+ * KingsHand observes events from multiple sources and delivers them to listeners.
- * to listeners.
  *
  */
 public class KingsHand extends EventEmitter implements EventObserver {

event-aggregator/src/main/java/com/iluwatar/event/aggregator/Weekday.java

@@ -7,7 +7,8 @@ package com.iluwatar.event.aggregator;
  */
 public enum Weekday {
 
-	MONDAY("Monday"), TUESDAY("Tuesday"), WEDNESDAY("Wednesday"), THURSDAY("Thursday"), FRIDAY("Friday"), SATURDAY("Saturday"), SUNDAY("Sunday");
+  MONDAY("Monday"), TUESDAY("Tuesday"), WEDNESDAY("Wednesday"), THURSDAY("Thursday"), FRIDAY(
+      "Friday"), SATURDAY("Saturday"), SUNDAY("Sunday");
 
   private String description;
 

event-aggregator/src/test/java/com/iluwatar/event/aggregator/AppTest.java

@@ -1,4 +1,5 @@
 package com.iluwatar.event.aggregator;
+
 import org.junit.Test;
 
 import com.iluwatar.event.aggregator.App;

execute-around/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>execute-around</artifactId>
   <dependencies>

execute-around/src/main/java/com/iluwatar/execute/around/App.java

@@ -4,23 +4,24 @@ import java.io.FileWriter;
 import java.io.IOException;
 
 /**
- * The Execute Around idiom specifies some code to be executed before and after
+ * The Execute Around idiom specifies some code to be executed before and after a method. Typically
- * a method. Typically the idiom is used when the API has methods to be executed in
+ * the idiom is used when the API has methods to be executed in pairs, such as resource
- * pairs, such as resource allocation/deallocation or lock acquisition/release.
+ * allocation/deallocation or lock acquisition/release.
  * <p>
- * In this example, we have {@link SimpleFileWriter} class that opens and closes the file
+ * In this example, we have {@link SimpleFileWriter} class that opens and closes the file for the
- * for the user. The user specifies only what to do with the file by providing the
+ * user. The user specifies only what to do with the file by providing the {@link FileWriterAction}
- * {@link FileWriterAction} implementation.
+ * implementation.
  *
  */
 public class App {
 
   /**
    * Program entry point
+   * 
    * @param args command line args
    * @throws IOException
    */
-    public static void main( String[] args ) throws IOException {
+  public static void main(String[] args) throws IOException {
 
     new SimpleFileWriter("testfile.txt", new FileWriterAction() {
 

execute-around/src/main/java/com/iluwatar/execute/around/SimpleFileWriter.java

@@ -5,9 +5,8 @@ import java.io.IOException;
 
 /**
  * 
- * SimpleFileWriter handles opening and closing file for the user. The user
+ * SimpleFileWriter handles opening and closing file for the user. The user only has to specify what
- * only has to specify what to do with the file resource through {@link FileWriterAction}
+ * to do with the file resource through {@link FileWriterAction} parameter.
- * parameter.
  *
  */
 public class SimpleFileWriter {

facade/pom.xml

@@ -5,7 +5,7 @@
   <parent>
     <groupId>com.iluwatar</groupId>
     <artifactId>java-design-patterns</artifactId>
-    <version>1.7.0</version>
+    <version>1.8.0</version>
   </parent>
   <artifactId>facade</artifactId>
   <dependencies>

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

@@ -2,21 +2,22 @@ package com.iluwatar.facade;
 
 /**
  * 
- * The Facade design pattern is often used when a system is very complex or difficult 
+ * The Facade design pattern is often used when a system is very complex or difficult to understand
- * to understand because the system has a large number of interdependent classes or 
+ * because the system has a large number of interdependent classes or its source code is
- * its source code is unavailable. This pattern hides the complexities of the larger 
+ * unavailable. This pattern hides the complexities of the larger system and provides a simpler
- * system and provides a simpler interface to the client. It typically involves a single 
+ * interface to the client. It typically involves a single wrapper class which contains a set of
- * wrapper class which contains a set of members required by client. These members access 
+ * members required by client. These members access the system on behalf of the facade client and
- * the system on behalf of the facade client and hide the implementation details.
+ * hide the implementation details.
  * <p>
- * In this example the Facade is ({@link DwarvenGoldmineFacade}) and it provides a simpler 
+ * In this example the Facade is ({@link DwarvenGoldmineFacade}) and it provides a simpler interface
- * interface to the goldmine subsystem.
+ * to the goldmine subsystem.
  * 
  */
 public class App {
 
   /**
    * Program entry point
+   * 
    * @param args command line args
    */
   public static void main(String[] args) {

facade/src/main/java/com/iluwatar/facade/DwarvenCartOperator.java

@@ -16,5 +16,4 @@ public class DwarvenCartOperator extends DwarvenMineWorker {
   public String name() {
     return "Dwarf cart operator";
   }
-
 }