How to stop the task scheduled in java.util.Timer class

Either call cancel() on the Timer if that's all it's doing, or cancel() on the TimerTask if the timer itself has other tasks which you wish to continue.

Keep a reference to the timer somewhere, and use:

timer.cancel();
timer.purge();

to stop whatever it's doing. You could put this code inside the task you're performing with a static int to count the number of times you've gone around, e.g.

private static int count = 0;
public static void run() {
     count++;
     if (count >= 6) {
         timer.cancel();
         timer.purge();
         return;
     }

     ... perform task here ....

}