code refactor

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

@@ -30,12 +30,10 @@ package com.iluwatar.command;
  *
  * <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 is
- * executed. 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 a reference of the command object to the invoker object.
+ * receiver. An invoker object (wizard) receives a reference to the command to be executed and
+ * optionally does bookkeeping about the command execution. The invoker does not know anything
+ * about how the command is executed. The client decides which commands to execute at which
+ * points. To execute a command, it passes a reference of the function 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 spells cast, so it is easy to undo them. In addition, the wizard keeps track of

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

@@ -42,21 +42,4 @@ public class Goblin extends Target {
   public String toString() {
     return "Goblin";
   }
-
-  /**
-   * changeSize.
-   */
-  public void changeSize() {
-    var oldSize = getSize() == Size.NORMAL ? Size.SMALL : Size.NORMAL;
-    setSize(oldSize);
-  }
-
-  /**
-   * changeVisibility.
-   */
-  public void changeVisibility() {
-    var visible = getVisibility() == Visibility.INVISIBLE
-            ? Visibility.VISIBLE : Visibility.INVISIBLE;
-    setVisibility(visible);
-  }
 }

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

@@ -62,4 +62,21 @@ public abstract class Target {
   public void printStatus() {
     LOGGER.info("{}, [size={}] [visibility={}]", this, getSize(), getVisibility());
   }
+
+  /**
+   * Changes the size of the target.
+   */
+  public void changeSize() {
+    var oldSize = getSize() == Size.NORMAL ? Size.SMALL : Size.NORMAL;
+    setSize(oldSize);
+  }
+
+  /**
+   * Changes the visibility of the target.
+   */
+  public void changeVisibility() {
+    var visible = getVisibility() == Visibility.INVISIBLE
+            ? Visibility.VISIBLE : Visibility.INVISIBLE;
+    setVisibility(visible);
+  }
 }