Comment fermer la fenêtre en Java

//Frame1.java   
import java.awt.*;   
import java.awt.event.*;   
import javax.swing.*;   
public class Frame1 extends JFrame {   
public Frame1() {   
enableEvents(AWTEvent.WINDOW_EVENT_MASK);   
this.setSize(new Dimension(400, 300));   
this.setTitle("Frame1");   
}   
protected void processWindowEvent(WindowEvent e) {   
super.processWindowEvent(e);   
if (e.getID() == WindowEvent.WINDOW_CLOSING) {   
System.exit(0);   
}   
}   
}

//Frame1.java   
import java.awt.*;   
import java.awt.event.*;   
public class Frame1 extends Frame implements WindowListener {   
public Frame1() {   
this.setSize(new Dimension(400, 300));   
this.setTitle("Frame1");   
this.addWindowListener(this);   
}   
public void windowClosing(WindowEvent windowEvent) {   
System.exit(0);   
}   
public void windowOpened(WindowEvent windowEvent) { }   
public void windowClosed(WindowEvent windowEvent) { }   
public void windowIconified(WindowEvent windowEvent) { }   
public void windowDeiconified(WindowEvent windowEvent) { }   
public void windowActivated(WindowEvent windowEvent) { }   
public void windowDeactivated(WindowEvent windowEvent) { }   
}

//Frame1.java   
import java.awt.*;   
import java.awt.event.*;   
public class Frame1 extends WindowAdapter {   
public Frame1() {   
Frame f=new Frame();   
f.setSize(new Dimension(400, 300));   
f.setTitle("Frame1");   
f.addWindowListener(this);   
f.setVisible(true);   
}   
public static void main(String[] s){   
new Frame1();   
}   
public void windowClosing(WindowEvent windowEvent) {   
System.exit(0);   
}   
}

//Frame1.java   
import java.awt.*;   
import java.awt.event.*;   
public class Frame1 extends Frame {   
public Frame1() {   
this.setSize(new Dimension(400, 300));   
this.setTitle("Frame1");   
this.addWindowListener(new winAdapter());   
this.setVisible(true);   
}   
public static void main(String[] s){   
new Frame1();   
}   
}   
class winAdapter extends WindowAdapter{   
public void windowClosing(WindowEvent windowEvent) {   
System.exit(0);   
}   
}

//Frame1.java   
import java.awt.*;   
import java.awt.event.*;   
public class Frame1 extends Frame {   
public Frame1() {   
this.setSize(new Dimension(400, 300));   
this.setTitle("Frame1");   
this.addWindowListener(new winEventHandle());   
this.setVisible(true);   
}   
public static void main(String[] s){   
new Frame1();   
}   
}   
class winEventHandle implements WindowListener {   
public void windowClosing(WindowEvent windowEvent) {   
System.exit(0);   
}   
public void windowOpened(WindowEvent windowEvent) { }   
public void windowClosed(WindowEvent windowEvent) { }   
public void windowIconified(WindowEvent windowEvent) { }   
public void windowDeiconified(WindowEvent windowEvent) { }   
public void windowActivated(WindowEvent windowEvent) { }   
public void windowDeactivated(WindowEvent windowEvent) { }   
}

//Frame1.java   
import java.awt.*;   
import java.awt.event.*;   
public class Frame1{   
public Frame1(){   
Frame f=new Frame();   
f.addWindowListener(new WindowAdapter(){   
public void windowClosing(WindowEvent e){   
System.exit(0);   
}   
});   
f.setSize(new Dimension(400, 300));   
f.setVisible(true);   
}   
public static void main(String[] s){   
new Frame1();   
}   
}

setDefaultCloseOperation(EXIT_ON_CLOSE);

this.addWindowListener(new java.awt.event.WindowAdapter() {   
public void windowClosing(java.awt.event.WindowEvent e) {   
System.exit(0);   
}   
});