ScheduleAtFixedRate - not catching interupt from FutureTask.cancel()

Question

I'm not quite understanding how to correctly cancel a thread that is spawned with scheduleAtFixedRate.
main() schedules the MyTask runnable to run every second (which works fine). The runnable (MyTask) prints that its running every second. main() waits 5 seconds then calls cancel (implemented by FutureTask). This is where I get confused. cancel() (if called with a true flag) is supposed to interrupt the thread, but I never get a print in my catch for an InterruptException, and I never fall into my Thread.interupted() condition.
So I have 3 questions:
1. When I run this code from eclipse, the runnable does stop running (I stop getting the prints). So it does seem to be getting canceled. However, I don't understand why I'm not catching the thread interrupt.
2. I'm forced to use the application terminate button in Eclipse to stop execution (not sure why it doesn't terminate normally).
3. Whats the advantage of scheduleAtFixedRate over just spawning the thread with a while(shutdownFlag==true) loop (with a sleep at the end of the loop) and using a volatile atomic boolean to set the flag to false and have the thread terminate?
Thanks for any help!
     public static void main(String[] args) {
          final int THREAD_POOL_SIZE = 1;
          final int PERIODIC_TIME = 1;
          final ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(THREAD_POOL_SIZE);
          MyTaskSingleton myTask = MyTaskSingleton.getInstance();          
          try {
                  final ScheduledFuture<?> myTaskHandle =
                              scheduler.scheduleAtFixedRate(myTask, 0, PERIODIC_TIME, TimeUnit.SECONDS);
               Thread.sleep(5000);
               System.out.println("TaskExecutor: MyTask cancel: " + myTaskHandle.cancel(true));
               Thread.sleep(1000);
               System.out.println("TaskExecutor: MyTask is done: " + myTaskHandle.isDone());
          } catch (InterruptedException e) {
               System.out.println("TaskExecutor: caught exception");
               e.printStackTrace();
     }Here is the run method of my runnable class.
public void run() {
          try {
               if (Thread.interrupted()){
                    System.out.println("MyTask: detected thread interrupt");                    
                    throw new InterruptedException();
               System.out.println("MyTask: running...");
          catch(InterruptedException e){
               System.out.println("MyTask: caught Interrupt Exception");
               e.printStackTrace();
     }

Answer 1

1. the only way your runnable will see an interrupted exception, is if it happens to be running when the cancel method is called. however, seeing as your run method is so trivial, the chances of the cancellation happening at the exact right time are very low. add a call to Thread.sleep() in your run method and you have a way better chance of seeing the interruption in the run method.
2. you need to shutdown the executor at the end of the main method. the thread it is using is keeping the application from exiting.
3. because you don't have to write all the code your self. not to mention that you can use 1 thread for multiple scheduled tasks (if you need more than 1).