如何延迟Java？ [英] How do I make a delay in Java?

问题描述

我正在尝试用Java做一些事情，我需要在while循环中等待/延迟一段时间。

I am trying to do something in Java and I need something to wait / delay for an amount of seconds in a while loop.

while (true) {
    if (i == 3) {
        i = 0;
    }

    ceva[i].setSelected(true);

    // I need to wait here

    ceva[i].setSelected(false);

    // I need to wait here

    i++;
}

我想构建一个步序器，我是Java的新手。有什么建议吗？

I want to build a step sequencer and I'm new to Java. Any suggestions?

推荐答案

如果你想暂停，那就用 java.util.concurrent.TimeUnit ：

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

TimeUnit.SECONDS.sleep(1);

睡一秒或

TimeUnit.MINUTES.sleep(1);

睡一分钟。

由于这是一个循环，这提出了一个固有的问题 - 漂移。每次你运行代码然后再睡觉时，你会每隔一秒就跑步一次。如果这是一个问题，那么不要使用 sleep 。

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.

此外， sleep 在控制方面不是很灵活。

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

对于每秒或延迟一秒运行任务，我会强烈推荐 ScheduledExecutorService 和 scheduleAtFixedRate 或 scheduleWithFixedDelay 。

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

例如，运行方法 myTask 每秒（Java 8）：

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");
}

在Java 7中：

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");
}

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