public abstract void windowActivated(WindowEvent e);
public abstract void windowClosed(WindowEvent e);
public abstract void windowClosing(WindowEvent e);
public abstract void windowDeactivated(WindowEvent e);
public abstract void windowDeiconified(WindowEvent e);
public abstract void windowIconified(WindowEvent e);
public abstract void windowOpened(WindowEvent e);

import java.awt.*;
import java.awt.event.WindowEvent;
import java.awt.event.WindowListener;
public class WindowExample extends Frame implements WindowListener{
WindowExample(){
addWindowListener(this);

setSize(400,400);
setLayout(null);
setVisible(true);
}

public static void main(String[] args) {
new WindowExample();
}
public void windowActivated(WindowEvent arg0) {
System.out.println("activated");
}
public void windowClosed(WindowEvent arg0) {
System.out.println("closed");
}
public void windowClosing(WindowEvent arg0) {
System.out.println("closing");
dispose();
}
public void windowDeactivated(WindowEvent arg0) {
System.out.println("deactivated");
}
public void windowDeiconified(WindowEvent arg0) {
System.out.println("deiconified");
}
public void windowIconified(WindowEvent arg0) {
System.out.println("iconified");
}
public void windowOpened(WindowEvent arg0) {
System.out.println("opened");
}
}