在工作中停止在Scheduuledexecutorservice中停止工作

Question

注意：这是玩具代码而不是准备好。

我想安排MyTask运行每个固定延迟（例如2秒）。当完成时，这项任务希望自己停止。MyTask的代码为：

public class MyTask implements Runnable {
    MainClass parent;
    AtomicInteger integer = new AtomicInteger(0);
    public MyTask(MainClass parent) {
        this.parent = parent;
    }
    @Override
    public void run() {
        try {
            int valueNow = integer.incrementAndGet();
            System.out.println("Running with value: " + valueNow + " and going to do work");
            Thread.sleep((long)(Math.random() * 10000)); // simulate some work
            System.out.println("Running with value: " + valueNow + " and work over");
            if(valueNow == 5) {
                parent.stopTask();
            }
        } catch (Exception exception) {
            System.out.println("Interrupted");
        }
    }
}

和MainClass是安排它的一个：

public class MainClass {
    private ScheduledExecutorService executorService;
    private ScheduledFuture updateFuture;
    public static void main(String[] args) {
        new MainClass().startMyTask();
    }
    public void startMyTask() {
        System.out.println("Starting MyTask to run every 2 seconds..............");
        executorService = Executors.newScheduledThreadPool(2);
        updateFuture = executorService.scheduleAtFixedRate(new MyTask(this), 1, 2, TimeUnit.SECONDS);
    }
    public void stopTask() {
       System.out.println("Stopping MyTask to run further");
       updateFuture.cancel(true);
    }
}

这只是复制场景的玩具代码。此方法有什么问题我将对父母的引用传递给线程以便可以停止？有什么更好的方法？

Answer 1

好吧，'错误'是您在两个类之间创建一个环状依赖关系。它会起作用，但循环依赖性通常是不可取的。

，但很容易打破周期。您的任务不是通过父本身，而是可以接受Runnable在完成后运行。基本上是一个回调。

public class MyTask implements Runnable {
    Runnable runOnDone;
    AtomicInteger integer = new AtomicInteger(0);
    public MyTask(Runnable runOnDone) {
        this.runOnDone = runOnDone;
    }
    @Override
    public void run() {
        try {
            int valueNow = integer.incrementAndGet();
            System.out.println("Running with value: " + valueNow + " and going to do work");
            Thread.sleep((long)(Math.random() * 10000)); // simulate some work
            System.out.println("Running with value: " + valueNow + " and work over");
            if(valueNow == 5) {
                runOnDone.run();
            }
        } catch (Exception exception) {
            System.out.println("Interrupted");
        }
    }
}

然后可以像这样实例化任务： new MyTask(this::stopTask)

另外，您可以从任务中抛出异常，这也将结束重新安排。请参阅此stackoverflow答案。