Resolves checkstyle errors for naked-objects null-object object-mother object-pool observer queue-load-leveling (#1082)

* Reduces checkstyle errors in naked-objects

* Reduces checkstyle errors in null-object

* Reduces checkstyle errors in object-mother

* Reduces checkstyle errors in object-pool

* Reduces checkstyle errors in observer

* Reduces checkstyle errors in queue-load-leveling

naked-objects/dom/src/main/java/domainapp/dom/app/homepage/HomePageService.java

@@ -31,7 +31,8 @@ import org.apache.isis.applib.annotation.NatureOfService;
 import org.apache.isis.applib.annotation.SemanticsOf;
 
 /**
- * HomePage Domain Service
+ * HomePage Domain Service.
+ *
  * @see HomePageViewModel linked view to HomePage
  */
 @DomainService(nature = NatureOfService.VIEW_CONTRIBUTIONS_ONLY)

naked-objects/dom/src/main/java/domainapp/dom/app/homepage/HomePageViewModel.java

@@ -23,16 +23,14 @@
 
 package domainapp.dom.app.homepage;
 
-import java.util.List;
-
-import org.apache.isis.applib.annotation.ViewModel;
-
 import domainapp.dom.modules.simple.SimpleObject;
 import domainapp.dom.modules.simple.SimpleObjects;
+import java.util.List;
+import org.apache.isis.applib.annotation.ViewModel;
 
 /**
- * Model linked to the HomePage
+ * Model linked to the HomePage The underlying layout is specified by json.
- * The underlying layout is specified by json
+ *
  * @see HomePageService - Service Linked to the HomePage
  */
 @ViewModel

naked-objects/dom/src/main/java/domainapp/dom/app/homepage/HomePageViewModel.layout.json

@@ -15,29 +15,29 @@
  *  limitations under the License.
  */
 {
-    "columns": [
+  "columns": [
-        {
+    {
-            "span": 0,
+      "span": 0,
-            "memberGroups": {}
+      "memberGroups": {}
-        },
+    },
-        {
+    {
-            "span": 0,
+      "span": 0,
-            "memberGroups": {}
+      "memberGroups": {}
-        },
+    },
-        {
+    {
-            "span": 0,
+      "span": 0,
-            "memberGroups": {}
+      "memberGroups": {}
-        },
+    },
-        {
+    {
-            "span": 12,
+      "span": 12,
-            "collections": {
+      "collections": {
-                "objects": {
+        "objects": {
-                    "collectionLayout": {
+          "collectionLayout": {
-                        "render": "EAGERLY"
+            "render": "EAGERLY"
-                    }
+          }
-                }
-            }
         }
-    ],
+      }
-    "actions": {}
+    }
+  ],
+  "actions": {}
 }

naked-objects/dom/src/main/java/domainapp/dom/modules/simple/SimpleObject.java

@@ -26,7 +26,6 @@ package domainapp.dom.modules.simple;
 import javax.jdo.JDOHelper;
 import javax.jdo.annotations.IdentityType;
 import javax.jdo.annotations.VersionStrategy;
-
 import org.apache.isis.applib.DomainObjectContainer;
 import org.apache.isis.applib.Identifier;
 import org.apache.isis.applib.annotation.Action;
@@ -43,7 +42,7 @@ import org.apache.isis.applib.services.i18n.TranslatableString;
 import org.apache.isis.applib.util.ObjectContracts;
 
 /**
- * Definition of a Simple Object
+ * Definition of a Simple Object.
  */
 @javax.jdo.annotations.PersistenceCapable(identityType = IdentityType.DATASTORE, schema = "simple",
     table = "SimpleObject")
@@ -87,11 +86,11 @@ public class SimpleObject implements Comparable<SimpleObject> {
   // region > updateName (action)
 
   /**
-   * Event used to update the Name in the Domain
+   * Event used to update the Name in the Domain.
    */
   public static class UpdateNameDomainEvent extends ActionDomainEvent<SimpleObject> {
     public UpdateNameDomainEvent(final SimpleObject source, final Identifier identifier,
-        final Object... arguments) {
+                                 final Object... arguments) {
       super(source, identifier, arguments);
     }
   }

naked-objects/dom/src/main/java/domainapp/dom/modules/simple/SimpleObject.layout.json

@@ -15,42 +15,42 @@
  *  limitations under the License.
  */
 {
-    "columns": [
+  "columns": [
-        {
+    {
-            "span": 6,
+      "span": 6,
-            "memberGroups": {
+      "memberGroups": {
-                "General": {
+        "General": {
-                    "members": {
+          "members": {
-                        "name": {
+            "name": {
-                            "actions": {
+              "actions": {
-                                "updateName": {
+                "updateName": {
-                                    "actionLayout": {
+                  "actionLayout": {
-                                        "position": "BOTTOM"
+                    "position": "BOTTOM"
-                                    }
+                  }
-                                }
-                            }
-                        },
-                        "versionSequence": {
-                            "propertyLayout": {
-                                "name": "version"
-                            }
-                        }
-                    }
                 }
+              }
+            },
+            "versionSequence": {
+              "propertyLayout": {
+                "name": "version"
+              }
             }
-        },
+          }
-        {
-            "span": 0,
-            "memberGroups": {}
-        },
-        {
-            "span": 0,
-            "memberGroups": {}
-        },
-        {
-            "span": 6,
-            "collections": {}
         }
-    ],
+      }
-    "actions": {}
+    },
+    {
+      "span": 0,
+      "memberGroups": {}
+    },
+    {
+      "span": 0,
+      "memberGroups": {}
+    },
+    {
+      "span": 6,
+      "collections": {}
+    }
+  ],
+  "actions": {}
 }

naked-objects/dom/src/main/java/domainapp/dom/modules/simple/SimpleObjects.java

@@ -24,7 +24,6 @@
 package domainapp.dom.modules.simple;
 
 import java.util.List;
-
 import org.apache.isis.applib.DomainObjectContainer;
 import org.apache.isis.applib.Identifier;
 import org.apache.isis.applib.annotation.Action;
@@ -40,7 +39,7 @@ import org.apache.isis.applib.services.eventbus.ActionDomainEvent;
 import org.apache.isis.applib.services.i18n.TranslatableString;
 
 /**
- * Domain Service for Simple Objects
+ * Domain Service for Simple Objects.
  */
 @DomainService(repositoryFor = SimpleObject.class)
 @DomainServiceLayout(menuOrder = "10")
@@ -82,18 +81,18 @@ public class SimpleObjects {
   // endregion
 
   /**
-   * Create Domain Event on SimpleObjects
+   * Create Domain Event on SimpleObjects.
    */
   // region > create (action)
   public static class CreateDomainEvent extends ActionDomainEvent<SimpleObjects> {
     public CreateDomainEvent(final SimpleObjects source, final Identifier identifier,
-        final Object... arguments) {
+                             final Object... arguments) {
       super(source, identifier, arguments);
     }
   }
 
   /**
-   * Create simple object
+   * Create simple object.
    */
   @Action(domainEvent = CreateDomainEvent.class)
   @MemberOrder(sequence = "3")

naked-objects/fixture/src/main/java/domainapp/fixture/DomainAppFixturesProvider.java

@@ -23,14 +23,13 @@
 
 package domainapp.fixture;
 
+import domainapp.fixture.scenarios.RecreateSimpleObjects;
 import org.apache.isis.applib.annotation.DomainService;
 import org.apache.isis.applib.annotation.NatureOfService;
 import org.apache.isis.applib.fixturescripts.FixtureScripts;
 import org.apache.isis.applib.services.fixturespec.FixtureScriptsSpecification;
 import org.apache.isis.applib.services.fixturespec.FixtureScriptsSpecificationProvider;
 
-import domainapp.fixture.scenarios.RecreateSimpleObjects;
-
 /**
  * Specifies where to find fixtures, and other settings.
  */

naked-objects/fixture/src/main/java/domainapp/fixture/modules/simple/SimpleObjectCreate.java

@@ -23,13 +23,12 @@
 
 package domainapp.fixture.modules.simple;
 
-import org.apache.isis.applib.fixturescripts.FixtureScript;
-
 import domainapp.dom.modules.simple.SimpleObject;
 import domainapp.dom.modules.simple.SimpleObjects;
+import org.apache.isis.applib.fixturescripts.FixtureScript;
 
 /**
- * Fixture to create a simple object
+ * Fixture to create a simple object.
  */
 public class SimpleObjectCreate extends FixtureScript {
 
@@ -46,7 +45,7 @@ public class SimpleObjectCreate extends FixtureScript {
   private String name;
 
   /**
-   * Name of the object (required)
+   * Name of the object (required).
    */
   public String getName() {
     return name;

naked-objects/fixture/src/main/java/domainapp/fixture/modules/simple/SimpleObjectsTearDown.java

@@ -27,7 +27,7 @@ import org.apache.isis.applib.fixturescripts.FixtureScript;
 import org.apache.isis.applib.services.jdosupport.IsisJdoSupport;
 
 /**
- * TearDown/Cleanup for SimpleObjects
+ * TearDown/Cleanup for SimpleObjects.
  */
 public class SimpleObjectsTearDown extends FixtureScript {
 

naked-objects/fixture/src/main/java/domainapp/fixture/scenarios/RecreateSimpleObjects.java

@@ -27,19 +27,18 @@ import com.google.common.collect.Lists;
 import domainapp.dom.modules.simple.SimpleObject;
 import domainapp.fixture.modules.simple.SimpleObjectCreate;
 import domainapp.fixture.modules.simple.SimpleObjectsTearDown;
-import org.apache.isis.applib.fixturescripts.FixtureScript;
-
 import java.util.Collections;
 import java.util.List;
+import org.apache.isis.applib.fixturescripts.FixtureScript;
 
 
 /**
- * Create a bunch of simple Objects
+ * Create a bunch of simple Objects.
  */
 public class RecreateSimpleObjects extends FixtureScript {
 
   public final List<String> names = Collections.unmodifiableList(List.of("Foo", "Bar", "Baz",
-          "Frodo", "Froyo", "Fizz", "Bip", "Bop", "Bang", "Boo"));
+      "Frodo", "Froyo", "Fizz", "Bip", "Bop", "Bang", "Boo"));
 
   // region > number (optional input)
   private Integer number;

naked-objects/webapp/src/main/java/domainapp/webapp/SimpleApplication.java

@@ -23,13 +23,6 @@
 
 package domainapp.webapp;
 
-import java.io.IOException;
-import java.io.InputStream;
-import java.nio.charset.Charset;
-import java.util.List;
-
-import javax.servlet.http.HttpServletRequest;
-
 import com.google.common.base.Joiner;
 import com.google.common.io.Resources;
 import com.google.inject.AbstractModule;
@@ -37,30 +30,31 @@ import com.google.inject.Module;
 import com.google.inject.name.Names;
 import com.google.inject.util.Modules;
 import com.google.inject.util.Providers;
-
+import de.agilecoders.wicket.core.Bootstrap;
+import de.agilecoders.wicket.core.settings.IBootstrapSettings;
+import de.agilecoders.wicket.themes.markup.html.bootswatch.BootswatchTheme;
+import de.agilecoders.wicket.themes.markup.html.bootswatch.BootswatchThemeProvider;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.charset.Charset;
+import java.util.List;
+import javax.servlet.http.HttpServletRequest;
+import org.apache.isis.viewer.wicket.viewer.IsisWicketApplication;
+import org.apache.isis.viewer.wicket.viewer.integration.wicket.AuthenticatedWebSessionForIsis;
 import org.apache.wicket.Session;
 import org.apache.wicket.request.IRequestParameters;
 import org.apache.wicket.request.Request;
 import org.apache.wicket.request.Response;
 import org.apache.wicket.request.http.WebRequest;
-
-import org.apache.isis.viewer.wicket.viewer.IsisWicketApplication;
-import org.apache.isis.viewer.wicket.viewer.integration.wicket.AuthenticatedWebSessionForIsis;
-
-import de.agilecoders.wicket.core.Bootstrap;
-import de.agilecoders.wicket.core.settings.IBootstrapSettings;
-import de.agilecoders.wicket.themes.markup.html.bootswatch.BootswatchTheme;
-import de.agilecoders.wicket.themes.markup.html.bootswatch.BootswatchThemeProvider;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 
 /**
  * As specified in <tt>web.xml</tt>.
- * 
+ *
- * <p>
+ * <p>See:
- * See:
+ *
- * 
  * <pre>
  * &lt;filter&gt;
  *   &lt;filter-name&gt;wicket&lt;/filter-name&gt;
@@ -71,7 +65,6 @@ import org.slf4j.LoggerFactory;
  *    &lt;/init-param&gt;
  * &lt;/filter&gt;
  * </pre>
- * 
  */
 public class SimpleApplication extends IsisWicketApplication {
 
@@ -80,11 +73,10 @@ public class SimpleApplication extends IsisWicketApplication {
 
   /**
    * uncomment for a (slightly hacky) way of allowing logins using query args, eg:
-   * 
+   *
    * <tt>{@code ?user=sven&pass=pass}</tt>
-   * 
+   *
-   * <p>
+   * <p>for demos only, obvious.
-   * for demos only, obvious.
    */
   private static final boolean DEMO_MODE_USING_CREDENTIALS_AS_QUERYARGS = false;
 

null-object/src/main/java/com/iluwatar/nullobject/App.java

@@ -24,18 +24,16 @@
 package com.iluwatar.nullobject;
 
 /**
- * 
  * Null Object pattern replaces null values with neutral objects. Many times this simplifies
  * algorithms since no extra null checks are needed.
- * <p>
- * In this example we build a binary tree where the nodes are either normal or Null Objects. No null
- * values are used in the tree making the traversal easy.
  *
+ * <p>In this example we build a binary tree where the nodes are either normal or Null Objects. No
+ * null values are used in the tree making the traversal easy.
  */
 public class App {
   /**
-   * Program entry point
+   * Program entry point.
-   * 
+   *
    * @param args command line args
    */
   public static void main(String[] args) {
@@ -44,7 +42,7 @@ public class App {
         new NodeImpl("1", new NodeImpl("11", new NodeImpl("111", NullNode.getInstance(),
             NullNode.getInstance()), NullNode.getInstance()), new NodeImpl("12",
             NullNode.getInstance(), new NodeImpl("122", NullNode.getInstance(),
-                NullNode.getInstance())));
+            NullNode.getInstance())));
 
     root.walk();
   }

null-object/src/main/java/com/iluwatar/nullobject/Node.java

@@ -24,9 +24,7 @@
 package com.iluwatar.nullobject;
 
 /**
- * 
  * Interface for binary tree node.
- *
  */
 public interface Node {
 

null-object/src/main/java/com/iluwatar/nullobject/NodeImpl.java

@@ -27,9 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
  * Implementation for binary tree's normal nodes.
- *
  */
 public class NodeImpl implements Node {
 
@@ -40,7 +38,7 @@ public class NodeImpl implements Node {
   private final Node right;
 
   /**
-   * Constructor
+   * Constructor.
    */
   public NodeImpl(String name, Node left, Node right) {
     this.name = name;

null-object/src/main/java/com/iluwatar/nullobject/NullNode.java

@@ -24,17 +24,16 @@
 package com.iluwatar.nullobject;
 
 /**
- * 
  * Null Object implementation for binary tree node.
- * <p>
- * Implemented as Singleton, since all the NullNodes are the same.
  *
+ * <p>Implemented as Singleton, since all the NullNodes are the same.
  */
 public final class NullNode implements Node {
 
   private static NullNode instance = new NullNode();
 
-  private NullNode() {}
+  private NullNode() {
+  }
 
   public static NullNode getInstance() {
     return instance;

object-mother/src/main/java/com/iluwatar/objectmother/King.java

@@ -24,7 +24,7 @@
 package com.iluwatar.objectmother;
 
 /**
- * Defines all attributes and behaviour related to the King
+ * Defines all attributes and behaviour related to the King.
  */
 public class King implements Royalty {
   boolean isDrunk = false;
@@ -56,6 +56,7 @@ public class King implements Royalty {
 
   /**
    * Method to flirt to a queen.
+   *
    * @param queen Queen which should be flirted.
    */
   public void flirt(Queen queen) {

object-mother/src/main/java/com/iluwatar/objectmother/Queen.java

@@ -24,7 +24,7 @@
 package com.iluwatar.objectmother;
 
 /**
- * Defines all attributes and behaviour related to the Queen
+ * Defines all attributes and behaviour related to the Queen.
  */
 public class Queen implements Royalty {
   private boolean isDrunk = false;
@@ -61,6 +61,7 @@ public class Queen implements Royalty {
 
   /**
    * Method which is called when the king is flirting to a queen.
+   *
    * @param king King who initialized the flirt.
    * @return A value which describes if the flirt was successful or not.
    */

object-mother/src/main/java/com/iluwatar/objectmother/Royalty.java

@@ -24,7 +24,7 @@
 package com.iluwatar.objectmother;
 
 /**
- * Interface contracting Royalty Behaviour
+ * Interface contracting Royalty Behaviour.
  */
 public interface Royalty {
   void makeDrunk();

object-mother/src/main/java/com/iluwatar/objectmother/RoyaltyObjectMother.java

@@ -24,12 +24,13 @@
 package com.iluwatar.objectmother;
 
 /**
- * Object Mother Pattern generating Royalty Types
+ * Object Mother Pattern generating Royalty Types.
  */
 public final class RoyaltyObjectMother {
 
   /**
    * Method to create a sober and unhappy king. The standard parameters are set.
+   *
    * @return An instance of {@link com.iluwatar.objectmother.King} with the standard properties.
    */
   public static King createSoberUnhappyKing() {
@@ -38,6 +39,7 @@ public final class RoyaltyObjectMother {
 
   /**
    * Method of the object mother to create a drunk king.
+   *
    * @return A drunk {@link com.iluwatar.objectmother.King}.
    */
   public static King createDrunkKing() {
@@ -48,6 +50,7 @@ public final class RoyaltyObjectMother {
 
   /**
    * Method to create a happy king.
+   *
    * @return A happy {@link com.iluwatar.objectmother.King}.
    */
   public static King createHappyKing() {
@@ -58,6 +61,7 @@ public final class RoyaltyObjectMother {
 
   /**
    * Method to create a happy and drunk king.
+   *
    * @return A drunk and happy {@link com.iluwatar.objectmother.King}.
    */
   public static King createHappyDrunkKing() {
@@ -69,6 +73,7 @@ public final class RoyaltyObjectMother {
 
   /**
    * Method to create a flirty queen.
+   *
    * @return A flirty {@link com.iluwatar.objectmother.Queen}.
    */
   public static Queen createFlirtyQueen() {
@@ -79,6 +84,7 @@ public final class RoyaltyObjectMother {
 
   /**
    * Method to create a not flirty queen.
+   *
    * @return A not flirty {@link com.iluwatar.objectmother.Queen}.
    */
   public static Queen createNotFlirtyQueen() {

object-pool/src/main/java/com/iluwatar/object/pool/App.java

@@ -27,32 +27,30 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
  * When it is necessary to work with a large number of objects that are particularly expensive to
  * instantiate and each object is only needed for a short period of time, the performance of an
  * entire application may be adversely affected. An object pool design pattern may be deemed
  * desirable in cases such as these.
- * <p>
+ *
- * The object pool design pattern creates a set of objects that may be reused. When a new object is
+ * <p>The object pool design pattern creates a set of objects that may be reused. When a new object
- * needed, it is requested from the pool. If a previously prepared object is available it is
+ * is needed, it is requested from the pool. If a previously prepared object is available it is
  * returned immediately, avoiding the instantiation cost. If no objects are present in the pool, a
  * new item is created and returned. When the object has been used and is no longer needed, it is
  * returned to the pool, allowing it to be used again in the future without repeating the
  * computationally expensive instantiation process. It is important to note that once an object has
  * been used and returned, existing references will become invalid.
- * <p>
- * In this example we have created {@link OliphauntPool} inheriting from generic {@link ObjectPool}.
- * {@link Oliphaunt}s can be checked out from the pool and later returned to it. The pool tracks
- * created instances and their status (available, inUse).
  *
+ * <p>In this example we have created {@link OliphauntPool} inheriting from generic {@link
+ * ObjectPool}. {@link Oliphaunt}s can be checked out from the pool and later returned to it. The
+ * pool tracks created instances and their status (available, inUse).
  */
 public class App {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
 
   /**
-   * Program entry point
+   * Program entry point.
-   * 
+   *
    * @param args command line args
    */
   public static void main(String[] args) {

object-pool/src/main/java/com/iluwatar/object/pool/ObjectPool.java

@@ -27,7 +27,8 @@ import java.util.HashSet;
 import java.util.Set;
 
 /**
- * Generic object pool
+ * Generic object pool.
+ *
  * @param <T> Type T of Object in the Pool
  */
 public abstract class ObjectPool<T> {
@@ -38,7 +39,7 @@ public abstract class ObjectPool<T> {
   protected abstract T create();
 
   /**
-   * Checkout object from pool
+   * Checkout object from pool.
    */
   public synchronized T checkOut() {
     if (available.isEmpty()) {

object-pool/src/main/java/com/iluwatar/object/pool/Oliphaunt.java

@@ -26,9 +26,7 @@ package com.iluwatar.object.pool;
 import java.util.concurrent.atomic.AtomicInteger;
 
 /**
- * 
+ * Oliphaunts are expensive to create.
- * Oliphaunts are expensive to create
- *
  */
 public class Oliphaunt {
 
@@ -37,7 +35,7 @@ public class Oliphaunt {
   private final int id;
 
   /**
-   * Constructor
+   * Constructor.
    */
   public Oliphaunt() {
     id = counter.incrementAndGet();

object-pool/src/main/java/com/iluwatar/object/pool/OliphauntPool.java

@@ -24,9 +24,7 @@
 package com.iluwatar.object.pool;
 
 /**
- * 
+ * Oliphaunt object pool.
- * Oliphaunt object pool
- *
  */
 public class OliphauntPool extends ObjectPool<Oliphaunt> {
 

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

@@ -30,25 +30,23 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
  * The Observer pattern is a software design pattern in which an object, called the subject,
  * maintains a list of its dependents, called observers, and notifies them automatically of any
  * state changes, usually by calling one of their methods. It is mainly used to implement
  * distributed event handling systems. The Observer pattern is also a key part in the familiar
  * model–view–controller (MVC) architectural pattern. The Observer pattern is implemented in
  * numerous programming libraries and systems, including almost all GUI toolkits.
- * <p>
+ *
- * In this example {@link Weather} has a state that can be observed. The {@link Orcs} and
+ * <p>In this example {@link Weather} has a state that can be observed. The {@link Orcs} and {@link
- * {@link Hobbits} register as observers and receive notifications when the {@link Weather} changes.
+ * Hobbits} register as observers and receive notifications when the {@link Weather} changes.
- * 
  */
 public class App {
 
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
 
   /**
-   * Program entry point
+   * Program entry point.
-   * 
+   *
    * @param args command line args
    */
   public static void main(String[] args) {
@@ -64,13 +62,13 @@ public class App {
 
     // Generic observer inspired by Java Generics and Collection by Naftalin & Wadler
     LOGGER.info("--Running generic version--");
-    GWeather gWeather = new GWeather();
+    GWeather genericWeather = new GWeather();
-    gWeather.addObserver(new GOrcs());
+    genericWeather.addObserver(new GOrcs());
-    gWeather.addObserver(new GHobbits());
+    genericWeather.addObserver(new GHobbits());
 
-    gWeather.timePasses();
+    genericWeather.timePasses();
-    gWeather.timePasses();
+    genericWeather.timePasses();
-    gWeather.timePasses();
+    genericWeather.timePasses();
-    gWeather.timePasses();
+    genericWeather.timePasses();
   }
 }

observer/src/main/java/com/iluwatar/observer/Hobbits.java

@@ -27,9 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
+ * Hobbits.
- * Hobbits
- *
  */
 public class Hobbits implements WeatherObserver {
 

observer/src/main/java/com/iluwatar/observer/Orcs.java

@@ -27,9 +27,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
+ * Orcs.
- * Orcs
- *
  */
 public class Orcs implements WeatherObserver {
 

observer/src/main/java/com/iluwatar/observer/Weather.java

@@ -23,17 +23,14 @@
 
 package com.iluwatar.observer;
 
+import java.util.ArrayList;
+import java.util.List;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.ArrayList;
-import java.util.List;
-
 /**
- * 
  * Weather can be observed by implementing {@link WeatherObserver} interface and registering as
  * listener.
- * 
  */
 public class Weather {
 
@@ -56,7 +53,7 @@ public class Weather {
   }
 
   /**
-   * Makes time pass for weather
+   * Makes time pass for weather.
    */
   public void timePasses() {
     WeatherType[] enumValues = WeatherType.values();

observer/src/main/java/com/iluwatar/observer/WeatherObserver.java

@@ -24,9 +24,7 @@
 package com.iluwatar.observer;
 
 /**
- * 
  * Observer interface.
- * 
  */
 public interface WeatherObserver {
 

observer/src/main/java/com/iluwatar/observer/WeatherType.java

@@ -24,9 +24,7 @@
 package com.iluwatar.observer;
 
 /**
- * 
+ * WeatherType enumeration.
- * WeatherType enumeration
- * 
  */
 public enum WeatherType {
 

observer/src/main/java/com/iluwatar/observer/generic/GHobbits.java

@@ -28,9 +28,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
+ * GHobbits.
- * GHobbits
- *
  */
 public class GHobbits implements Race {
 

observer/src/main/java/com/iluwatar/observer/generic/GOrcs.java

@@ -28,9 +28,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
+ * GOrcs.
- * GOrcs
- *
  */
 public class GOrcs implements Race {
 

observer/src/main/java/com/iluwatar/observer/generic/GWeather.java

@@ -28,9 +28,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
+ * GWeather.
- * GWeather
- *
  */
 public class GWeather extends Observable<GWeather, Race, WeatherType> {
 
@@ -43,7 +41,7 @@ public class GWeather extends Observable<GWeather, Race, WeatherType> {
   }
 
   /**
-   * Makes time pass for weather
+   * Makes time pass for weather.
    */
   public void timePasses() {
     WeatherType[] enumValues = WeatherType.values();

observer/src/main/java/com/iluwatar/observer/generic/Observable.java

@@ -27,7 +27,7 @@ import java.util.List;
 import java.util.concurrent.CopyOnWriteArrayList;
 
 /**
- * Generic observer inspired by Java Generics and Collection by {@literal Naftalin & Wadler}
+ * Generic observer inspired by Java Generics and Collection by {@literal Naftalin & Wadler}.
  *
  * @param <S> Subject
  * @param <O> Observer
@@ -50,7 +50,7 @@ public abstract class Observable<S extends Observable<S, O, A>, O extends Observ
   }
 
   /**
-   * Notify observers
+   * Notify observers.
    */
   @SuppressWarnings("unchecked")
   public void notifyObservers(A argument) {

observer/src/main/java/com/iluwatar/observer/generic/Observer.java

@@ -24,7 +24,8 @@
 package com.iluwatar.observer.generic;
 
 /**
- * Observer
+ * Observer.
+ *
  * @param <S> Observable
  * @param <O> Observer
  * @param <A> Action

observer/src/main/java/com/iluwatar/observer/generic/Race.java

@@ -26,9 +26,7 @@ package com.iluwatar.observer.generic;
 import com.iluwatar.observer.WeatherType;
 
 /**
- * 
+ * Race.
- * Race
- *
  */
 public interface Race extends Observer<GWeather, Race, WeatherType> {
 }

queue-load-leveling/src/main/java/com/iluwatar/queue/load/leveling/App.java

@@ -26,69 +26,69 @@ package com.iluwatar.queue.load.leveling;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
-
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
+ * Many solutions in the cloud involve running tasks that invoke services. In this environment, if a
- * Many solutions in the cloud involve running tasks that invoke services. In this environment, 
+ * service is subjected to intermittent heavy loads, it can cause performance or reliability
- * if a service is subjected to intermittent heavy loads, it can cause performance or reliability issues.
+ * issues.
- * <p>
+ *
- * A service could be a component that is part of the same solution as the tasks that utilize it, or it 
+ * <p>A service could be a component that is part of the same solution as the tasks that utilize
- * could be a third-party service providing access to frequently used resources such as a cache or a storage service.
+ * it, or it could be a third-party service providing access to frequently used resources such as a
- * If the same service is utilized by a number of tasks running concurrently, it can be difficult to predict the 
+ * cache or a storage service. If the same service is utilized by a number of tasks running
- * volume of requests to which the service might be subjected at any given point in time.
+ * concurrently, it can be difficult to predict the volume of requests to which the service might be
- * <p>
+ * subjected at any given point in time.
- * We will build a queue-based-load-leveling to solve above problem. 
+ *
- * Refactor the solution and introduce a queue between the task and the service. 
+ * <p>We will build a queue-based-load-leveling to solve above problem. Refactor the solution and
- * The task and the service run asynchronously. The task posts a message containing the data required 
+ * introduce a queue between the task and the service. The task and the service run asynchronously.
- * by the service to a queue. The queue acts as a buffer, storing the message until it is retrieved 
+ * The task posts a message containing the data required by the service to a queue. The queue acts
- * by the service. The service retrieves the messages from the queue and processes them. 
+ * as a buffer, storing the message until it is retrieved by the service. The service retrieves the
- * Requests from a number of tasks, which can be generated at a highly variable rate, can be passed 
+ * messages from the queue and processes them. Requests from a number of tasks, which can be
- * to the service through the same message queue.
+ * generated at a highly variable rate, can be passed to the service through the same message
- * <p>
+ * queue.
- * The queue effectively decouples the tasks from the service, and the service can handle the messages 
+ *
- * at its own pace irrespective of the volume of requests from concurrent tasks. Additionally, 
+ * <p>The queue effectively decouples the tasks from the service, and the service can handle the
- * there is no delay to a task if the service is not available at the time it posts a message to the queue.
+ * messages at its own pace irrespective of the volume of requests from concurrent tasks.
- * <p>
+ * Additionally, there is no delay to a task if the service is not available at the time it posts a
- * In this example we have a class {@link MessageQueue} to hold the message {@link Message} objects. 
+ * message to the queue.
- * All the worker threads {@link TaskGenerator} will submit the messages to the MessageQueue. 
+ *
- * The service executor class {@link ServiceExecutor} will pick up one task at a time from the Queue and 
+ * <p>In this example we have a class {@link MessageQueue} to hold the message {@link Message}
- * execute them.
+ * objects. All the worker threads {@link TaskGenerator} will submit the messages to the
- *  
+ * MessageQueue. The service executor class {@link ServiceExecutor} will pick up one task at a time
+ * from the Queue and execute them.
  */
 public class App {
-  
+
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
-  
+
   //Executor shut down time limit.
   private static final int SHUTDOWN_TIME = 15;
-  
+
   /**
-   * Program entry point
+   * Program entry point.
-   * 
+   *
    * @param args command line args
    */
   public static void main(String[] args) {
-    
+
     // An Executor that provides methods to manage termination and methods that can 
     // produce a Future for tracking progress of one or more asynchronous tasks.
     ExecutorService executor = null;
-    
+
     try {
       // Create a MessageQueue object.
       MessageQueue msgQueue = new MessageQueue();
-        
+
       LOGGER.info("Submitting TaskGenerators and ServiceExecutor threads.");
-      
+
       // Create three TaskGenerator threads. Each of them will submit different number of jobs.
-      Runnable taskRunnable1 = new TaskGenerator(msgQueue, 5);
+      final Runnable taskRunnable1 = new TaskGenerator(msgQueue, 5);
-      Runnable taskRunnable2 = new TaskGenerator(msgQueue, 1);
+      final Runnable taskRunnable2 = new TaskGenerator(msgQueue, 1);
-      Runnable taskRunnable3 = new TaskGenerator(msgQueue, 2);
+      final Runnable taskRunnable3 = new TaskGenerator(msgQueue, 2);
-      
+
       // Create e service which should process the submitted jobs.
-      Runnable srvRunnable = new ServiceExecutor(msgQueue);
+      final Runnable srvRunnable = new ServiceExecutor(msgQueue);
 
       // Create a ThreadPool of 2 threads and
       // submit all Runnable task for execution to executor..
@@ -96,17 +96,18 @@ public class App {
       executor.submit(taskRunnable1);
       executor.submit(taskRunnable2);
       executor.submit(taskRunnable3);
-      
+
       // submitting serviceExecutor thread to the Executor service.
       executor.submit(srvRunnable);
-      
+
       // Initiates an orderly shutdown.
-      LOGGER.info("Intiating shutdown. Executor will shutdown only after all the Threads are completed.");
+      LOGGER.info("Initiating shutdown."
+          + " Executor will shutdown only after all the Threads are completed.");
       executor.shutdown();
-      
+
       // Wait for SHUTDOWN_TIME seconds for all the threads to complete 
       // their tasks and then shut down the executor and then exit. 
-      if ( !executor.awaitTermination(SHUTDOWN_TIME, TimeUnit.SECONDS) ) {
+      if (!executor.awaitTermination(SHUTDOWN_TIME, TimeUnit.SECONDS)) {
         LOGGER.info("Executor was shut down and Exiting.");
         executor.shutdownNow();
       }

queue-load-leveling/src/main/java/com/iluwatar/queue/load/leveling/Message.java

@@ -24,12 +24,11 @@
 package com.iluwatar.queue.load.leveling;
 
 /**
- *  Message class with only one parameter.
+ * Message class with only one parameter.
- *
+ */
-*/
 public class Message {
   private final String msg;
- 
+
   // Parameter constructor.
   public Message(String msg) {
     this.msg = msg;
@@ -39,7 +38,7 @@ public class Message {
   public String getMsg() {
     return msg;
   }
-  
+
   @Override
   public String toString() {
     return msg;

queue-load-leveling/src/main/java/com/iluwatar/queue/load/leveling/MessageQueue.java

@@ -25,30 +25,27 @@ package com.iluwatar.queue.load.leveling;
 
 import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.BlockingQueue;
-
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
+ * MessageQueue class. In this class we will create a Blocking Queue and submit/retrieve all the
- * MessageQueue class.
+ * messages from it.
- * In this class we will create a Blocking Queue and 
- * submit/retrieve all the messages from it.
  */
 public class MessageQueue {
-  
+
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
-  
+
   private final BlockingQueue<Message> blkQueue;
-  
+
   // Default constructor when called creates Blocking Queue object. 
   public MessageQueue() {
     this.blkQueue = new ArrayBlockingQueue<Message>(1024);
   }
-  
+
   /**
-   * All the TaskGenerator threads will call this method to insert the
+   * All the TaskGenerator threads will call this method to insert the Messages in to the Blocking
-   * Messages in to the Blocking Queue. 
+   * Queue.
    */
   public void submitMsg(Message msg) {
     try {
@@ -59,11 +56,10 @@ public class MessageQueue {
       LOGGER.error(e.getMessage());
     }
   }
-  
+
   /**
-   * All the messages will be retrieved by the ServiceExecutor by 
+   * All the messages will be retrieved by the ServiceExecutor by calling this method and process
-   * calling this method and process them.
+   * them. Retrieves and removes the head of this queue, or returns null if this queue is empty.
-   * Retrieves and removes the head of this queue, or returns null if this queue is empty.
    */
   public Message retrieveMsg() {
     Message retrievedMsg = null;
@@ -72,7 +68,7 @@ public class MessageQueue {
     } catch (Exception e) {
       LOGGER.error(e.getMessage());
     }
-    
+
     return retrievedMsg;
   }
 }

queue-load-leveling/src/main/java/com/iluwatar/queue/load/leveling/ServiceExecutor.java

@@ -27,10 +27,8 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * 
+ * ServiceExecuotr class. This class will pick up Messages one by one from the Blocking Queue and
- *  ServiceExecuotr class.
+ * process them.
- *  This class will pick up Messages one by one from 
- *  the Blocking Queue and process them.
  */
 public class ServiceExecutor implements Runnable {
 

queue-load-leveling/src/main/java/com/iluwatar/queue/load/leveling/Task.java

@@ -22,10 +22,10 @@
  */
 
 package com.iluwatar.queue.load.leveling;
+
 /**
  * Task Interface.
- * 
+ */
-*/
 public interface Task {
   void submit(Message msg);
 }

queue-load-leveling/src/main/java/com/iluwatar/queue/load/leveling/TaskGenerator.java

@@ -27,28 +27,26 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 /**
- * TaskGenerator class.
+ * TaskGenerator class. Each TaskGenerator thread will be a Worker which submit's messages to the
- * Each TaskGenerator thread will be a Worker which submit's messages to the queue.
+ * queue. We need to mention the message count for each of the TaskGenerator threads.
- * We need to mention the message count for each of the TaskGenerator threads.
+ */
- * 
-*/
 public class TaskGenerator implements Task, Runnable {
 
-  
+
   private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
-  
+
   // MessageQueue reference using which we will submit our messages.
   private final MessageQueue msgQueue;
-  
+
   // Total message count that a TaskGenerator will submit.
   private final int msgCount;
-  
+
   // Parameterized constructor.
   public TaskGenerator(MessageQueue msgQueue, int msgCount) {
     this.msgQueue = msgQueue;
     this.msgCount = msgCount;
   }
-  
+
   /**
    * Submit messages to the Blocking Queue.
    */
@@ -59,25 +57,25 @@ public class TaskGenerator implements Task, Runnable {
       LOGGER.error(e.getMessage());
     }
   }
-  
+
   /**
-   * Each TaskGenerator thread will submit all the messages to the Queue.
+   * Each TaskGenerator thread will submit all the messages to the Queue. After every message
-   * After every message submission TaskGenerator thread will sleep for 1 second.
+   * submission TaskGenerator thread will sleep for 1 second.
    */
   public void run() {
-    
+
     int count = this.msgCount;
-    
+
     try {
       while (count > 0) {
         String statusMsg = "Message-" + count + " submitted by " + Thread.currentThread().getName();
         this.submit(new Message(statusMsg));
-        
+
         LOGGER.info(statusMsg);
-        
+
         // reduce the message count.
         count--;
-        
+
         // Make the current thread to sleep after every Message submission.
         Thread.sleep(1000);
       }