how to start and stop the scheduledexecutorservice multiple times

Question

I am using ScheduledExecutorService, and after I call it's cancel method on scheduleFuture, I can't schedule a Runnable on it. Calling scheduleAtFixedRate(runnable, INITIAL_DELAY, INTERVAL, TimeUnit.SECONDS) after cancel() , nothing happens. Is there any way to restart the ScheduledExecutorService after cancel() method is called?

Answer 1

Please review notes on Future and its implementation FutureTask .

The effect of calling cancel() method is that:

• subsequent calls to isDone() will always return true. Subsequent
calls to isCancelled() will always return true if this method
returned true.
• Once the computation has completed, the computation cannot be restarted or cancelled.

Meaning, if a call to isDone() returns true , whether or not you made a call to cancel() , you can't use same instance of your service.