scheduleAtFixedRate vs scheduleWithFixedDelay

Question

What\'s the main difference between scheduleAtFixedRate and scheduleWithFixedDelay methods of ScheduledExecutorService?

scheduler.s         


        

Answer 1

If you read the Java Doc it will be clearer

ScheduledFuture scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit) Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given period; that is executions will commence after initialDelay then initialDelay+period, then initialDelay + 2 * period, and so on.

ScheduledFuture scheduleWithFixedDelay(Runnable command, long initialDelay, long delay, TimeUnit unit) Creates and executes a periodic action that becomes enabled first after the given initial delay, and subsequently with the given delay between the termination of one execution and the commencement of the next.