using a timer

import java.util.*;
import java.text.*;

public class Timer implements Runnable {

static SimpleDateFormat df=new SimpleDateFormat("dd.MM.yy hh:mm.ss");
Thread ticker=null;

public Timer() {}

public void start() {
if (ticker!=null && ticker.isAlive()) {
System.err.println("Timer is already running");
return;
}
ticker=new Thread(this);
ticker.start();
}
public void stop () {
ticker.interrupt();
ticker=null;
}

public void run() {
System.out.println("Timer started");
while (true) {
try {
ticker.sleep(1000);
}
catch (InterruptedException ex) {
System.out.println("Timer stopping");
return;
}
System.out.println(df.format(new java.util.Date(System.currentTimeMillis())));
}
}

public static void main(String[] args) {
Timer t = new Timer();
t.start();
}

}