Timer

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

public class JavaSimpleTimer extends JPanel implements ActionListener  
{  
 int miliseconds=0;  
 int seconds=0;  
 int minutes=0;  
   
 Timer myTimer;  
 Font timerFont=new Font("Verdana",Font.BOLD,24);  
   
 public JavaSimpleTimer()  
 {  
  myTimer=new Timer(10,this);    
  JFrame myFrame=new JFrame("Simple Timer");    
  myFrame.add(this);  
  myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
  myFrame.setSize(200,100);  
  myFrame.setVisible(true);  
  myTimer.setInitialDelay(0);  
  myTimer.start();  
 }  
  
 public void paint(Graphics g)  
 {  
  super.paint(g);  
  String mili=Integer.toString(miliseconds);  
  String sec=Integer.toString(seconds);  
  String min=Integer.toString(minutes);  
    
  if(mili.length()==1)  
  {  
   mili="0"+mili;  
  }  
  if(sec.length()==1)  
  {  
   sec="0"+sec;  
  }  
  if(min.length()==1)  
  {  
   min="0"+min;  
  }  
    
  g.setFont(timerFont);  
    
  g.drawString(min+" :",20,20);  
  g.drawString(sec+" :",80,20);  
  g.drawString(mili,140,20);  
 }  
   
 public void actionPerformed(ActionEvent event)  
 {  
  miliseconds=miliseconds+1;  
  if(miliseconds==100)  
  {  
   miliseconds=0;  
   seconds=seconds+1;  
  }  
  if(seconds==60)  
  {  
   seconds=0;  
   minutes=minutes+1;  
  }  
  repaint();  
 }  
   
 public static void main(String[]args)  
 {  
  JavaSimpleTimer myTest=new JavaSimpleTimer();  
 }  
}

Output:-