程序代码：

import java.awt.*;
import java.awt.event.*;
public class MyButton extends Button{
    private MyButton friend=null;
    public void setFriend(MyButton friend)
    {
        this.friend = friend;
    }
    public MyButton(String name)
    {
        super(name);
        enableEvents(AWTEvent.MOUSE_MOTION_EVENT_MASK);
    }
    protected void processMouseMotionEvent(MouseEvent e)
    {
        setVisible(false);
        friend.setVisible(true);
    }
}

public class TestMyButton extends Frame {

    public TestMyButton()
    {
        addWindowListener(new WindowAdapter()
        {
            public void windowClosing(WindowEvent e)
            {
                dispose();
                System.exit(0);
            }
        });
    }
    public static void main(String[] args) {
        // TODO: Add your code here
        System.out.println("Starting TestMyButton");
        TestMyButton mainFrame = new TestMyButton();
        mainFrame.setTitle("TestMyButton!");
        mainFrame.setVisible(true);
        mainFrame.setSize(500,500);
        MyButton btn1= new MyButton("你来抓我啊！");
        MyButton btn2= new MyButton("你来抓我啊！");


        btn1.setFriend(btn2);
        btn2.setFriend(btn1);
        mainFrame.add(btn1,"North");
        mainFrame.add(btn2,"South");
        btn2.setVisible(false);
    }
}