decrease number of checkstyle errors in singleton, strategy and visitor patterns #1021 (#1054)

* fix checkstlye errors - visitor pattern

* fix checkstlye errors - strategy pattern

* fix checkstlye errors - singleton pattern

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

@@ -24,19 +24,18 @@
 package com.iluwatar.visitor;
 
 /**
- * 
- * Visitor pattern defines mechanism to apply operations on nodes in hierarchy. New operations can
- * be added without altering the node interface.
- * <p>
- * In this example there is a unit hierarchy beginning from {@link Commander}. This hierarchy is
+ * <p>Visitor pattern defines mechanism to apply operations on nodes in hierarchy. New operations
+ * can be added without altering the node interface.</p>
+ *
+ * <p>In this example there is a unit hierarchy beginning from {@link Commander}. This hierarchy is
  * traversed by visitors. {@link SoldierVisitor} applies its operation on {@link Soldier}s,
- * {@link SergeantVisitor} on {@link Sergeant}s and so on.
+ * {@link SergeantVisitor} on {@link Sergeant}s and so on.</p>
  * 
  */
 public class App {
 
   /**
-   * Program entry point
+   * Program entry point.
    * 
    * @param args command line args
    */

visitor/src/main/java/com/iluwatar/visitor/Commander.java

@@ -24,9 +24,7 @@
 package com.iluwatar.visitor;
 
 /**
- * 
- * Commander
- *
+ * Commander.
  */
 public class Commander extends Unit {
 

visitor/src/main/java/com/iluwatar/visitor/CommanderVisitor.java

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

visitor/src/main/java/com/iluwatar/visitor/Sergeant.java

@@ -24,9 +24,7 @@
 package com.iluwatar.visitor;
 
 /**
- * 
- * Sergeant
- *
+ * Sergeant.
  */
 public class Sergeant extends Unit {
 

visitor/src/main/java/com/iluwatar/visitor/SergeantVisitor.java

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

visitor/src/main/java/com/iluwatar/visitor/Soldier.java

@@ -24,9 +24,7 @@
 package com.iluwatar.visitor;
 
 /**
- * 
- * Soldier
- *
+ * Soldier.
  */
 public class Soldier extends Unit {
 

visitor/src/main/java/com/iluwatar/visitor/SoldierVisitor.java

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

visitor/src/main/java/com/iluwatar/visitor/Unit.java

@@ -24,9 +24,7 @@
 package com.iluwatar.visitor;
 
 /**
- * 
  * Interface for the nodes in hierarchy.
- * 
  */
 public abstract class Unit {
 
@@ -37,7 +35,7 @@ public abstract class Unit {
   }
 
   /**
-   * Accept visitor
+   * Accept visitor.
    */
   public void accept(UnitVisitor visitor) {
     for (var child : children) {

visitor/src/main/java/com/iluwatar/visitor/UnitVisitor.java

@@ -24,9 +24,7 @@
 package com.iluwatar.visitor;
 
 /**
- * 
  * Visitor interface.
- * 
  */
 public interface UnitVisitor {
 

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

@@ -26,9 +26,7 @@ package com.iluwatar.visitor;
 import org.junit.jupiter.api.Test;
 
 /**
- * 
- * Application test
- *
+ * Application test.
  */
 public class AppTest {
 

visitor/src/test/java/com/iluwatar/visitor/CommanderTest.java

@@ -27,14 +27,14 @@ import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.verify;
 
 /**
- * Date: 12/30/15 - 19:45 PM
+ * Date: 12/30/15 - 19:45 PM.
  *
  * @author Jeroen Meulemeester
  */
 public class CommanderTest extends UnitTest<Commander> {
 
   /**
-   * Create a new test instance for the given {@link Commander}
+   * Create a new test instance for the given {@link Commander}.
    */
   public CommanderTest() {
     super(Commander::new);

visitor/src/test/java/com/iluwatar/visitor/CommanderVisitorTest.java

@@ -26,14 +26,14 @@ package com.iluwatar.visitor;
 import java.util.Optional;
 
 /**
- * Date: 12/30/15 - 18:43 PM
+ * Date: 12/30/15 - 18:43 PM.
  *
  * @author Jeroen Meulemeester
  */
 public class CommanderVisitorTest extends VisitorTest<CommanderVisitor> {
 
   /**
-   * Create a new test instance for the given visitor
+   * Create a new test instance for the given visitor.
    */
   public CommanderVisitorTest() {
     super(

visitor/src/test/java/com/iluwatar/visitor/SergeantTest.java

@@ -27,14 +27,14 @@ import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.verify;
 
 /**
- * Date: 12/30/15 - 19:45 PM
+ * Date: 12/30/15 - 19:45 PM.
  *
  * @author Jeroen Meulemeester
  */
 public class SergeantTest extends UnitTest<Sergeant> {
 
   /**
-   * Create a new test instance for the given {@link Sergeant}
+   * Create a new test instance for the given {@link Sergeant}.
    */
   public SergeantTest() {
     super(Sergeant::new);

visitor/src/test/java/com/iluwatar/visitor/SergeantVisitorTest.java

@@ -26,14 +26,14 @@ package com.iluwatar.visitor;
 import java.util.Optional;
 
 /**
- * Date: 12/30/15 - 18:36 PM
+ * Date: 12/30/15 - 18:36 PM.
  *
  * @author Jeroen Meulemeester
  */
 public class SergeantVisitorTest extends VisitorTest<SergeantVisitor> {
 
   /**
-   * Create a new test instance for the given visitor
+   * Create a new test instance for the given visitor.
    */
   public SergeantVisitorTest() {
     super(

visitor/src/test/java/com/iluwatar/visitor/SoldierTest.java

@@ -27,14 +27,14 @@ import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.verify;
 
 /**
- * Date: 12/30/15 - 19:45 PM
+ * Date: 12/30/15 - 19:45 PM.
  *
  * @author Jeroen Meulemeester
  */
 public class SoldierTest extends UnitTest<Soldier> {
 
   /**
-   * Create a new test instance for the given {@link Soldier}
+   * Create a new test instance for the given {@link Soldier}.
    */
   public SoldierTest() {
     super(Soldier::new);

visitor/src/test/java/com/iluwatar/visitor/SoldierVisitorTest.java

@@ -26,14 +26,14 @@ package com.iluwatar.visitor;
 import java.util.Optional;
 
 /**
- * Date: 12/30/15 - 18:59 PM
+ * Date: 12/30/15 - 18:59 PM.
  *
  * @author Jeroen Meulemeester
  */
 public class SoldierVisitorTest extends VisitorTest<SoldierVisitor> {
 
   /**
-   * Create a new test instance for the given visitor
+   * Create a new test instance for the given visitor.
    */
   public SoldierVisitorTest() {
     super(

visitor/src/test/java/com/iluwatar/visitor/UnitTest.java

@@ -23,18 +23,18 @@
 
 package com.iluwatar.visitor;
 
-import org.junit.jupiter.api.Test;
-
-import java.util.Arrays;
-import java.util.function.Function;
-
 import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 
+import java.util.Arrays;
+import java.util.function.Function;
+
+import org.junit.jupiter.api.Test;
+
 /**
- * Date: 12/30/15 - 18:59 PM
+ * Date: 12/30/15 - 18:59 PM.
  * Test related to Units
  * @param <U> Type of Unit
  * @author Jeroen Meulemeester
@@ -42,12 +42,12 @@ import static org.mockito.Mockito.verifyNoMoreInteractions;
 public abstract class UnitTest<U extends Unit> {
 
   /**
-   * Factory to create new instances of the tested unit
+   * Factory to create new instances of the tested unit.
    */
   private final Function<Unit[], U> factory;
 
   /**
-   * Create a new test instance for the given unit type {@link U}
+   * Create a new test instance for the given unit type {@link U}.
    *
    * @param factory Factory to create new instances of the tested unit
    */
@@ -74,7 +74,7 @@ public abstract class UnitTest<U extends Unit> {
   }
 
   /**
-   * Verify if the correct visit method is called on the mock, depending on the tested instance
+   * Verify if the correct visit method is called on the mock, depending on the tested instance.
    *
    * @param unit          The tested unit instance
    * @param mockedVisitor The mocked {@link UnitVisitor} who should have gotten a visit by the unit

visitor/src/test/java/com/iluwatar/visitor/VisitorTest.java

@@ -23,6 +23,8 @@
 
 package com.iluwatar.visitor;
 
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
 import ch.qos.logback.classic.Logger;
 import ch.qos.logback.classic.spi.ILoggingEvent;
 import ch.qos.logback.core.AppenderBase;
@@ -35,10 +37,8 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.slf4j.LoggerFactory;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
 /**
- * Date: 12/30/15 - 18:59 PM
+ * Date: 12/30/15 - 18:59 PM.
  * Test case for Visitor Pattern
  * @param <V> Type of UnitVisitor
  * @author Jeroen Meulemeester
@@ -58,34 +58,36 @@ public abstract class VisitorTest<V extends UnitVisitor> {
   }
 
   /**
-   * The tested visitor instance
+   * The tested visitor instance.
    */
   private final V visitor;
 
   /**
-   * The optional expected response when being visited by a commander
+   * The optional expected response when being visited by a commander.
    */
   private final Optional<String> commanderResponse;
 
   /**
-   * The optional expected response when being visited by a sergeant
+   * The optional expected response when being visited by a sergeant.
    */
   private final Optional<String> sergeantResponse;
 
   /**
-   * The optional expected response when being visited by a soldier
+   * The optional expected response when being visited by a soldier.
    */
   private final Optional<String> soldierResponse;
 
   /**
-   * Create a new test instance for the given visitor
+   * Create a new test instance for the given visitor.
    *
    * @param commanderResponse The optional expected response when being visited by a commander
    * @param sergeantResponse  The optional expected response when being visited by a sergeant
    * @param soldierResponse   The optional expected response when being visited by a soldier
    */
-  public VisitorTest(final V visitor, final Optional<String> commanderResponse,
-                     final Optional<String> sergeantResponse, final Optional<String> soldierResponse) {
+  public VisitorTest(final V visitor,
+                     final Optional<String> commanderResponse,
+                     final Optional<String> sergeantResponse,
+                     final Optional<String> soldierResponse) {
 
     this.visitor = visitor;
     this.commanderResponse = commanderResponse;