多线程与高并发(12)——BlockingQueue

BlockingQueue主要用来控制线程通信，当生产者试图向阻塞队列中放入元素而BlockingQueue已满，则该线程被阻塞。当消费者试图向阻塞队列中取出元素而BlockingQueue已满，则该线程被阻塞。(这里元素添加、删除使用put()，take()方法才会阻塞，使用add()/offer()，remove()/pull()则有其它表现)

BlockingQueue的一个基于数组的实现类就是ArrayBlockingQueue，请看下列示例代码。

class Producer extends Thread {
    private BlockingQueue<String> bq;

    public Producer(BlockingQueue<String> bq) {
        this.bq = bq;
    }

    @Override
    public void run() {
        String[] str = new String[] { "hello,", "world!", "I'm wz" };
        for (int i = 0; i < 99999; i++) {
            System.out.println(getName() + "start produce item!");
            try {
                Thread.sleep(200);
                bq.put(str[i % 3]);
            } catch (Exception e) {
                e.printStackTrace();
            }
            System.out.println(getName() + "finish produce item!" + bq);
        }

    }
}

class Consumer extends Thread {
    private BlockingQueue<String> bq;

    public Consumer(BlockingQueue<String> bq) {
        this.bq = bq;
    }

    @Override
    public void run() {
        while (true) {
            System.out.println(getName() + "start Consume item!");
            try {
                Thread.sleep(200);
                bq.take();
            } catch (Exception e) {
                e.printStackTrace();
            }
            System.out.println(getName() + "finish Consume item!" + bq);
        }
    }
}

public class BlockingQueueTest {
    public static void main(String[] args) {
        BlockingQueue<String> bq = new ArrayBlockingQueue<>(1);
        new Producer(bq).start();
        new Producer(bq).start();
        new Producer(bq).start();
        new Consumer(bq).start();
    }
}