Improved the adapter pattern example. Updated the class diagram.

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

@@ -3,14 +3,15 @@ package com.iluwatar;
 /**
  * 
  * Adapter (GnomeEngineer) converts the interface of the
- * target class (GoblinGlider) into suitable one.
+ * target class (GoblinGlider) into suitable one expected
+ * by the client (GnomeEngineeringManager).
  *
  */
 public class App 
 {
     public static void main( String[] args )
     {
-    	GnomeEngineer engineer = new GnomeEngineer();
-    	engineer.operateDevice();
+    	GnomeEngineeringManager manager = new GnomeEngineeringManager();
+    	manager.operateDevice();
     }
 }

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

@@ -2,8 +2,7 @@ package com.iluwatar;
 
 /**
  * 
- * The interface the client knows how
- * to use.
+ * Engineers can operate devices.
  *
  */
 public interface Engineer {

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

@@ -2,9 +2,9 @@ package com.iluwatar;
 
 /**
  * 
- * Adapter class. Adapts the interface of the
- * GoblinGlider into Engineer expected by the
- * client.
+ * Adapter class. Adapts the interface of the device
+ * (GoblinGlider) into Engineer interface expected 
+ * by the client (GnomeEngineeringManager).
  *
  */
 public class GnomeEngineer implements Engineer {

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

@@ -0,0 +1,21 @@
+package com.iluwatar;
+
+/**
+ * 
+ * GnomeEngineering manager uses Engineer to
+ * operate devices.
+ *
+ */
+public class GnomeEngineeringManager implements Engineer {
+
+	private Engineer engineer;
+	
+	public GnomeEngineeringManager() {
+		engineer = new GnomeEngineer();
+	}
+	
+	@Override
+	public void operateDevice() {
+		engineer.operateDevice();
+	}
+}

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

@@ -2,21 +2,20 @@ package com.iluwatar;
 
 /**
  * 
- * Adaptee class.
+ * Device class (adaptee in the pattern).
  *
  */
 public class GoblinGlider {
 
 	public void attachGlider() {
-		System.out.println("glider attached");
+		System.out.println("Glider attached.");
 	}
 	
 	public void gainSpeed() {
-		System.out.println("gaining speed");
+		System.out.println("Gaining speed.");
 	}
 	
 	public void takeOff() {
-		System.out.println("lift-off!");
+		System.out.println("Lift-off!");
 	}
-	
 }