求JAVA編程源代碼 要求時鐘+計時器的功能

import java.util.Date;

import java.util.*;

import javax.swing.*;

import java.awt.Graphics;

import java.util.Calendar;

import java.util.GregorianCalendar;

//通過Runnable接口定義線程類

public class RunnableThread extends JApplet implements Runnable

{

Thread clockThread;

public void start()

{

if (clockThread==null)

{

clockThread=new Thread(this,"Clock");

clockThread.start();

}

}

public void run()

{

while(clockThread!=null)

{

repaint();//實際上是顯示壹個時鐘

try

{

clockThread.sleep(1000);

}catch(InterruptedException e) {}

}

}

public void paint(Graphics g)

{

super.paint(g);

Calendar now = GregorianCalendar.getInstance();

g.drawString(now.get(Calendar.HOUR)+":"+now.get(Calendar.MINUTE)+":"+now.get(Calendar.SECOND),5,10);

}

public void stop()

{

clockThread = null;

clockThread=null;

}

}