How do I make a delay in Java?

If you want to pause then use java.util.concurrent.TimeUnit:

TimeUnit.SECONDS.sleep(1);

To sleep for one second or

TimeUnit.MINUTES.sleep(1);

To sleep for a minute.

As this is a loop, this presents an inherent problem – drift. Every time you run code and then sleep you will be drifting a little bit from running, say, every second. If this is an issue then don’t use sleep.

Further, sleep isn’t very flexible when it comes to control.

For running a task every second or at a one second delay I would strongly recommend a ScheduledExecutorService and either scheduleAtFixedRate or scheduleWithFixedDelay.

For example, to run the method myTask every second (Java 8):

public static void main(String[] args) {
    final ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();
    executorService.scheduleAtFixedRate(App::myTask, 0, 1, TimeUnit.SECONDS);
}

private static void myTask() {
    System.out.println("Running");
}

And in Java 7:

public static void main(String[] args) {
    final ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();
    executorService.scheduleAtFixedRate(new Runnable() {
        @Override
        public void run() {
            myTask();
        }
    }, 0, 1, TimeUnit.SECONDS);
}

private static void myTask() {
    System.out.println("Running");
}

Leave a Comment