awt windowopened 不好用

import java.awt.*;
import java.awt.event.*;
import javax.swing.JOptionPane;public class WindowEventTest extends Frame implements ActionListener, WindowListener {    Button b1 = new Button("ok");
    TextField t1 = new TextField("mainclass");    public WindowEventTest() {
        setLayout(new FlowLayout());
        b1.addActionListener(this);        setSize(200, 200);
        setVisible(true);
        add(b1);
        add(t1);
        addWindowListener(this);
    }    public void actionPerformed(ActionEvent e) {
        Object source = e.getSource();
        if (source == b1) {
            t1.setText("hello");
        }    }    public void windowClosing(WindowEvent e) {
        //System.exit(1);
        this.dispose();
//        int result=JOptionPane.showConfirmDialog(this,"请确认是否退出程序");
//        if(result==JOptionPane.YES_OPTION){
//            System.exit(0);
//        }    }    public void windowActivated(WindowEvent e) {
        System.out.println("activated");
    }    public void windowClosed(WindowEvent e) {
        System.out.println("closed");
    }    public void windowDeactivated(WindowEvent e) {
        System.out.println("deactivated");
    }    public void windowDeiconified(WindowEvent e) {
        System.out.println("Deiconified");    }    public void windowIconified(WindowEvent e) {
        System.out.println("Iconified");
    }    public void windowOpened(WindowEvent e) {
       
        System.out.println("Opened");
    }    public static void main(String[] args) {
        new WindowEventTest();
    }
}请教各位，为什么public void windowOpened(WindowEvent e) {
       
        System.out.println("Opened");
    } 不起作用 谢谢各位了