Question

在我的应用程序中我们使用了线程池，我们已经为线程池指定了超时但似乎没有调用超时，下面是代码：

import java.sql.Timestamp;
import java.util.ArrayList;
import java.util.Date;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

public class ThreadPoolDemo extends Thread{

public void run(){
    System.out.println("Starting---" + new Timestamp((new Date()).getTime())  + "--" + Thread.currentThread().getName());
    try {
        Thread.sleep(30000);
    } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    System.out.println("Finishing---" + new Timestamp((new Date()).getTime())  + "--" +Thread.currentThread().getName());
}

public static void main (String[] args){
    ArrayBlockingQueue<Runnable> threadQueue = new ArrayBlockingQueue<Runnable>(5);
    ThreadPoolExecutor thumbnailGeneratorThreadPool = new ThreadPoolExecutor(1, 3,
            5, TimeUnit.SECONDS, threadQueue);
    thumbnailGeneratorThreadPool.allowCoreThreadTimeOut(true);
    ArrayList fTasks = new ArrayList();
    for (int i = 0; i < 15; i++) {
        System.out.println("Submitting Thread : " + (i+1) + "- Current Queue size is : " + threadQueue.size());
        ThreadPoolDemo tpd = new ThreadPoolDemo();
        Future future = thumbnailGeneratorThreadPool.submit(tpd);
    }
    }
}

代码的输出是：

Submitting Thread : 1- Current Queue size is : 0
Submitting Thread : 2- Current Queue size is : 0
Submitting Thread : 3- Current Queue size is : 1
Submitting Thread : 4- Current Queue size is : 2
Submitting Thread : 5- Current Queue size is : 3
Submitting Thread : 6- Current Queue size is : 4
Submitting Thread : 7- Current Queue size is : 5
Submitting Thread : 8- Current Queue size is : 5
Submitting Thread : 9- Current Queue size is : 5
Exception in thread "main" java.util.concurrent.RejectedExecutionException
    at java.util.concurrent.ThreadPoolExecutor$AbortPolicy.rejectedExecution(ThreadPoolExecutor.java:1774)
    at java.util.concurrent.ThreadPoolExecutor.reject(ThreadPoolExecutor.java:768)
    at java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:656)
    at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:78)
    at ThreadPoolDemo.main(ThreadPoolDemo.java:33)
Starting---2016-10-26 14:20:16.254--pool-1-thread-2
Starting---2016-10-26 14:20:16.254--pool-1-thread-3
Starting---2016-10-26 14:20:16.254--pool-1-thread-1
Finishing---2016-10-26 14:20:46.261--pool-1-thread-1
Finishing---2016-10-26 14:20:46.261--pool-1-thread-2
Finishing---2016-10-26 14:20:46.261--pool-1-thread-3
Starting---2016-10-26 14:20:46.261--pool-1-thread-2
Starting---2016-10-26 14:20:46.261--pool-1-thread-3
Starting---2016-10-26 14:20:46.261--pool-1-thread-1
Finishing---2016-10-26 14:21:16.265--pool-1-thread-1
Starting---2016-10-26 14:21:16.265--pool-1-thread-1
Finishing---2016-10-26 14:21:16.265--pool-1-thread-3
Starting---2016-10-26 14:21:16.265--pool-1-thread-3
Finishing---2016-10-26 14:21:16.265--pool-1-thread-2
Finishing---2016-10-26 14:21:46.277--pool-1-thread-1
Finishing---2016-10-26 14:21:46.277--pool-1-thread-3

现在在ThreadPoolExecutor keepAliveTime设置为5秒。

但是，如果我们看到输出，则线程需要30秒才能完成。我不确定为什么InterruptedException没有被线程上的ThreadPoolExecutor调用。

如果线程在指定的超时时间内仍处于活动状态，我想要一种机制来停止线程。

Answer 1

正如评论中已经指出的那样，您没有指定超时。您只指定了ThreadPoolExecutor的 keep-alive 时间。 keep-alive不会终止或中断正在运行的线程，而只会释放Executor的 idle 线程（请参阅getKeepAliveTime）。

如果您想为任务设置超时，则必须使用invokeAll或invokeAny方法而不是submit。另见

java ThreadPoolExecutor超时没有兑现

1 个答案: