Java ThreadPool报表

Question

我设置了一个工作线程池来执行一些工作，我希望将这些工作记录在一个中心位置。

更准确地说，我将Thread类扩展为worker类，用于检查并发队列的状态。如果它是空的，那么它会等待。当元素被另一个线程添加时，notify()唤醒工作线程。一旦他们完成了任务，他们就等待队列中的下一个元素。

让每个线程在每个任务结束时报告其状态的最佳实践是什么？

public class PoolWorker extends Thread {

public ConcurrentLinkedQueue<Device> q;

public PoolWorker(ConcurrentLinkedQueue<Device> q, String type){
    this.q = q;         
    this.type = type;
}

@Override 
public void run(){
    while (true)
    {
        Device d = null;
        try{
            synchronized(q){
                while(q.isEmpty())
                {
                    q.wait(); // wait for a notify()
                }
                d = q.remove();

            }
                            // do some work
                            // report status of work completed 
             }
}

Answer 1

如前所述，最好的方法是使用BlockingQueue。以下是示例代码：

public class PoolWorker extends Thread {
    public ArrayBlockingQueue<String> q;
    public String type;

    public PoolWorker(ArrayBlockingQueue<String> q, String type) {
        this.q = q;
        this.type = type;
    }

    @Override
    public void run() {
        while(true){
            String work = null;
            try {
                System.out.println("PoolWorker.run:waiting .............");
                work = q.take();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("PoolWorker.run..work: " + work);
        }

    }

    public static void main(String[] args) throws InterruptedException {
        ArrayBlockingQueue<String> pool = new ArrayBlockingQueue<String>(100);
        PoolWorker worker = new PoolWorker(pool, "Something");

        worker.start();
        addWork(pool, "work1");
        addWork(pool, "work2");
        addWork(pool, "work3");
        addWork(pool, "work4");
        addWork(pool, "work5");
        //Just give enough time to run
        Thread.sleep(5000);
    }


    private static void addWork(ArrayBlockingQueue<String> pool, String work) throws InterruptedException {
        System.out.println("PoolWorker.addWork: " + work);
        pool.put(work);
    }
}

在Java文档中也有很好的示例代码：http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/BlockingQueue.html

Answer 2

试着这样做

ExecutorService exec = Executors.newFixedThreadPool(10);
    Runnable runn = new Runnable() 
    {
        @Override
        public void run() 
        {
            System.out.println("");
        }
    };
    exec.execute(runn);