Java 11 migration: patterns (remaining b-c) (#1081)

* Moves business-delegate pattern  to java 11

* Moves bytecode pattern  to java 11

* Moves caching pattern  to java 11

* Moves callback pattern  to java 11

* Moves chain pattern  to java 11

* Moves circuit-breaker pattern  to java 11

* Moves collection-pipeline pattern  to java 11

* Moves command pattern  to java 11

* Moves commander pattern  to java 11

* Moves composite pattern  to java 11

* Corrects test cases

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

@@ -49,8 +49,8 @@ public class App {
    * @param args command line args
    */
   public static void main(String[] args) {
-    Wizard wizard = new Wizard();
-    Goblin goblin = new Goblin();
+    var wizard = new Wizard();
+    var goblin = new Goblin();
 
     goblin.printStatus();
 

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

@@ -41,7 +41,7 @@ public class ShrinkSpell extends Command {
   @Override
   public void undo() {
     if (oldSize != null && target != null) {
-      Size temp = target.getSize();
+      var temp = target.getSize();
       target.setSize(oldSize);
       oldSize = temp;
     }

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

@@ -56,7 +56,7 @@ public class Wizard {
    */
   public void undoLastSpell() {
     if (!undoStack.isEmpty()) {
-      Command previousSpell = undoStack.pollLast();
+      var previousSpell = undoStack.pollLast();
       redoStack.offerLast(previousSpell);
       LOGGER.info("{} undoes {}", this, previousSpell);
       previousSpell.undo();
@@ -68,7 +68,7 @@ public class Wizard {
    */
   public void redoLastSpell() {
     if (!redoStack.isEmpty()) {
-      Command previousSpell = redoStack.pollLast();
+      var previousSpell = redoStack.pollLast();
       undoStack.offerLast(previousSpell);
       LOGGER.info("{} redoes {}", this, previousSpell);
       previousSpell.redo();

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

@@ -25,15 +25,12 @@ package com.iluwatar.command;
 
 import org.junit.jupiter.api.Test;
 
-import java.io.IOException;
-
 /**
  * Tests that Command example runs without errors.
  */
 public class AppTest {
   @Test
-  public void test() throws IOException {
-    String[] args = {};
-    App.main(args);
+  public void test() {
+    App.main(new String[]{});
   }
 }

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

@@ -23,23 +23,23 @@
 
 package com.iluwatar.command;
 
-import org.junit.jupiter.api.Test;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import org.junit.jupiter.api.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.
+ *
+ * <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 {
 
@@ -53,8 +53,8 @@ public class CommandTest {
   @Test
   public void testCommand() {
 
-    Wizard wizard = new Wizard();
-    Goblin goblin = new Goblin();
+    var wizard = new Wizard();
+    var goblin = new Goblin();
 
     wizard.castSpell(new ShrinkSpell(), goblin);
     verifyGoblin(goblin, GOBLIN, Size.SMALL, Visibility.VISIBLE);
@@ -79,16 +79,17 @@ public class CommandTest {
    * 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 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 expectedVisibility expected visibility of the goblin
    */
   private void verifyGoblin(Goblin goblin, String expectedName, Size expectedSize,
-      Visibility expectedVisibility) {
+                            Visibility expectedVisibility) {
     assertEquals(expectedName, goblin.toString(), "Goblin's name must be same as expectedName");
     assertEquals(expectedSize, goblin.getSize(), "Goblin's size must be same as expectedSize");
     assertEquals(expectedVisibility, goblin.getVisibility(),
-            "Goblin's visibility must be same as expectedVisibility");
+        "Goblin's visibility must be same as expectedVisibility");
   }
 }