Java by API/java.awt.event/WindowAdapter

extends WindowAdapter

   <source lang="java">

import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JPanel; public class MainClass extends JPanel {

 public MainClass() {
   JButton btn1 = new JButton("Button1");
   add(btn1);
 }
 public static void main(String[] args) {
   JFrame frame = new JFrame();
   frame.getContentPane().add(new MainClass());
   //frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.addWindowListener(new FrameListener());
   
   frame.setSize(200, 200);
   frame.setVisible(true);
 }

} class FrameListener extends WindowAdapter {

  public void windowClosing(WindowEvent e)
 {
   System.exit(0);
 }

}

      </source>