请问用java怎样用窗口做一个90秒倒计时?

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;

public class Test extends JFrame
{
private JButton btn = new JButton("Start");
private JLabel label = new JLabel();
private int time = 90;
Test() {
setSize(500,300);
setLayout(new FlowLayout());
add(btn);
add(label);
btn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
new Thread(new MyThread()).start();
}
});
setVisible(true);
}

class MyThread implements Runnable
{
public void run() {
while (time > 0)
{
time--;
label.setText(time + "");
try
{
Thread.sleep(1000);
}
catch (Exception e)
{
e.printStackTrace();
}

}

Test.this.dispose();
}
};
public static void main(String[] args)
{
new Test();
}

}

写一个定时器，每一秒执行一次、然后计数器减1，计数器从90开始。。懂？

swing包
timer
也可以用线程