JAVA倒计时小程序

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Date;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JButton;

public class TestSuspend{
	public static void main(String[] args){
		JFrame jf = new JFrame("Timer");
		JButton pause = new JButton("Pause");
		JLabel clock = new JLabel("Timer");
		clock.setBackground(Color.GREEN);
		clock.setOpaque(true);
		clock.setHorizontalAlignment(JLabel.CENTER);
		jf.add(clock,"Center");
		jf.add(pause,"North");
		jf.setSize(140,80);
		jf.setLocation(500,300);
		jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		jf.setVisible(true);

		MyThread mt = new MyThread(clock,10000);
		mt.start();
		MyListener ml = new MyListener(clock,mt);
		pause.addActionListener(ml);
	}	
}

class MyThread extends Thread{
	private JLabel clock;
	private long time;
	private long end;
	
	public MyThread(JLabel clock,long time){
		this.clock = clock;	
		this.time = time;
	}
	public void init(){
		long start = new Date().getTime();
		end = start + time;
	}	
	public void run(){
		this.init();
		while(true){
			long now = new Date().getTime();
			time = end - now;
			if(time > 0){
				String s = this.convert(time);	
				clock.setText(s);
			}else{
				break;	
			}
			try{
				Thread.sleep(10);	
			}catch(InterruptedException e){
				e.printStackTrace();	
			}
		}
		clock.setText("时间到!");	
		clock.setBackground(Color.RED);
	}	
	public String convert(long time){
		long h = time / 3600000;
		long m = (time % 3600000) / 60000;
		long s = (time % 60000) / 1000;
		long ms = (time % 1000) / 10;
		String ph = h<10 ? "0":"";
		String pm = m<10 ? "0":"";
		String ps = s<10 ? "0":"";	
		String pms = ms<10 ? "0":"";	
		String txt = ph + h + ":" + pm + m + ":" + ps + s + "." + pms + ms; 
		return txt;
	}	
}

class MyListener implements ActionListener{
	private JLabel clock;
	private MyThread mt;
	private boolean running= true;
	
	public MyListener(JLabel clock,MyThread mt){
		this.clock = clock;
		this.mt = mt;
	}	
	public void actionPerformed(ActionEvent e){
		if(!mt.isAlive())
			return;
		JButton jb = (JButton)(e.getSource());
		if(running){
			jb.setText("Replay");
			clock.setBackground(Color.YELLOW);
			mt.suspend();
		}else{
			jb.setText("Pause");
			clock.setBackground(Color.green);
			mt.init();
			mt.resume();
		}
		running = !running;
	}	
}