如何在一段时间后退出while循环？ [英] How to exit a while loop after a certain time?

问题描述

我有一个while循环，我希望它在经过一段时间后退出。

I have a while loop and I want it to exit after some time has elapsed.

例如：

while(condition and 10 sec has not passed){

}

推荐答案

long startTime = System.currentTimeMillis(); //fetch starting time
while(false||(System.currentTimeMillis()-startTime)<10000)
{
    // do something
}

因此声明

(System.currentTimeMillis()-startTime)<10000

检查它是否为10秒或循环开始后10,000毫秒。

Checks if it has been 10 seconds or 10,000 milliseconds since the loop started.

编辑

正如@Julien指出的那样如果你的代码块在while循环中需要花费很多时间，这可能会失败。因此使用 ExecutorService 将是一个不错的选择。

As @Julien pointed out, this may fail if your code block inside the while loop takes a lot of time.Thus using ExecutorService would be a good option.

首先我们必须实现Runnable

First we would have to implement Runnable

class MyTask implements Runnable
{
    public void run() { 
        // add your code here
    }
}

然后我们可以像这样使用ExecutorService，

Then we can use ExecutorService like this,

ExecutorService executor = Executors.newSingleThreadExecutor();
executor.invokeAll(Arrays.asList(new MyTask()), 10, TimeUnit.SECONDS); // Timeout of 10 seconds.
executor.shutdown();

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