java怎么样实现一定概率时执行某个操作

public class ScheduledExecutorServiceTest {

private final ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);

public void beepForAnHour() {
    final Runnable beeper = new Runnable() {
        public void run() {
            //你的操作
            System.out.println("beep:"+Thread.currentThread().getName());
        }
    };
    //2000用随机数
    final ScheduledFuture<?> beeperHandle = scheduler.scheduleAtFixedRate(beeper, 0, 2000, TimeUnit.MILLISECONDS);
    scheduler.schedule(new Runnable() {
        public void run() {
            beeperHandle.cancel(true);
        }
    }, 36500, TimeUnit.DAYS);
}

public static void main(String[] args) {
    new ScheduledExecutorServiceTest().beepForAnHour();
}
}