A java.util.concurrent.ScheduledExecutorService interface is a subinterface of ExecutorService interface, and supports future and/or periodic execution of tasks.
Sr.No. | Method & Description |
---|---|
1 | <V> ScheduledFuture<V> schedule(Callable<V> callable, long delay, TimeUnit unit) Creates and executes a ScheduledFuture that becomes enabled after the given delay. |
2 | ScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit) Creates and executes a one-shot action that becomes enabled after the given delay. |
3 | 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. |
4 | 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. |
The following TestThread program shows usage of ScheduledExecutorService interface in thread based environment.
import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; import java.util.concurrent.ScheduledFuture; import java.util.concurrent.TimeUnit; public class TestThread { public static void main(final String[] arguments) throws InterruptedException { final ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1); final ScheduledFuture<?> beepHandler = scheduler.scheduleAtFixedRate(new BeepTask(), 2, 2, TimeUnit.SECONDS); scheduler.schedule(new Runnable() { @Override public void run() { beepHandler.cancel(true); scheduler.shutdown(); } }, 10, TimeUnit.SECONDS); } static class BeepTask implements Runnable { public void run() { System.out.println("beep"); } } }
This will produce the following result.
beep beep beep beep