709: Highlights

• Inner classes are classes defined inside other classes.
• Inner classes are available only in the class in which they are defined, and in that class's subclasses.
• If you want to create an application with a window such that the application terminates when the close button is clicked, then define a subclass of the JFrame class, then define an inner subclass of the WindowListener class, then define an appropriate windowClosing method for that inner class, and then connect an instance of the inner class to the JFrame subclass instance using addWindowListener:

  import javax.swing.*; 
  import java.awt.event.*; 
  public class application name extends JFrame { 
   public static void main (String argv []) { 
    new application name (title); 
   } 
   public application name(String title) { 
    super(title); 
    setSize(width, height); 
    addWindowListener(new LocalWindowListener()); 
    show(); 
   } 
   // Define window listener 
   private class LocalWindowListener extends WindowAdapter { 
    public void windowClosing(WindowEvent e) { 
      System.exit(0); 
    } 
   } 
  }