import java.awt.Graphics;
import java.awt.Color;
import java.util.Date;
import java.awt.Font;
import java.awt.*;
public class Digital extends java.applet.Applet implements Runnable{
Font m_fntFont = new Font("TimesRoman",Font.BOLD,24);
Date m_dntdate;
Thread m_thrunner;
public void run(){
while (true){
m_dntdate = new Date();
repaint();
try{
Thread.sleep(1000);
}//final try
catch(InterruptedException e){}
}//final while
}//final run
public void paint(Graphics g){
g.setFont(m_fntFont);
g.drawString(String.valueOf(m_dntdate),10,150);
}//final void paint
public void strat(){
if (m_thrunner == null){ //na verdade o exemplo estava if(runThread == null) mais nao rodava, e desta forma rodou
m_thrunner = new Thread(this);
m_thrunner.start();
}//final if
}//final void start
public void stop(){
if(m_thrunner != null){
m_thrunner.stop();
m_thrunner = null;
}//final if
}//final void stop
}//final do applet
<HTML>
<HEAD>
<TITLE> hTML COM JAVA </TITLE>
</HEAD><BODY bgcolor = "teal">
<font size="40" color = "green" > UM RELOGIO DIGITAL </p>
<APPLET CODE ="Digital.class" width="400" height="100" >
</APPLET>
</BODY>
</HTML>
antecipadamente agradeço