java - 当另一个线程终止时终止 Thread.Sleep() ？

Question

我不断从线程内的线程收到中断，它不会让我因此而破坏主线程。我仍然想使用 Thread.sleep() 来减慢循环速度。

主线程:

startEngine.setOnAction((ActionEvent e) -> {

        executor.submit(new Runnable() {
            @Override
            public void run() {
                while (!Thread.currentThread().isInterrupted()) {
                    lifeInstance.runEngine();
                }

            }

        });

    });

stopEngine.setOnAction((ActionEvent e) -> {
        executor.shutdownNow();
    });

executor.submit 正在调用 lifeInstance.runEngine()，即:

public void runEngine() {

    //logic...

    try {
        Thread.sleep(1000);
    } catch (InterruptedException ex) {
        Logger.getLogger(LifeEngine.class.getName()).log(Level.SEVERE, null, ex);

        return;
    }
}

错误:

//从 runEngine() 打印出内容

Nov 06, 2016 6:04:52 PM thecell.LifeEngine runEngine
SEVERE: null
java.lang.InterruptedException: sleep interrupted
    at java.lang.Thread.sleep(Native Method)
    at thecell.LifeEngine.runEngine(LifeEngine.java:66)
    at UIControls.RightControls$1.run(RightControls.java:48)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

//不断从 runEngine() 中打印出内容

Answer 1

因为当 runEngine() 方法在 InterruptedException 上返回时，isInterrupted() 返回 false。

摘自《Java并发实践》一书:

Blocking library methods like Thread.sleep and Object.wait try to detect when a thread has been interrupted and return early. They respond to interruption by clearing the interrupted status and throwing InterruptedException, indicating that the blocking operation completed early due to interruption.

当你得到异常时，中断状态被清除。您可以在返回前重置它:

} catch (InterruptedException ex) {
    Logger.getLogger(LifeEngine.class.getName()).log(Level.SEVERE, null, ex);
    Thread.currentThread().interrupt();
    return;
}

实际上，您应该这样做，因为您的任务代码是由线程池执行的，并且在任务代码处理完中断状态后保留中断状态是一个很好的行为。这样线程池也能响应中断。