生产者和消费者共享队列，其值来自 HttpRequest

Question

这是生产者/消费者的经典问题。当我引导我的 Spring Boot 应用程序时，我启动了两个线程。我只想在收到 httpRequest 时从 Producer 线程写入共享队列。那么，如何将此值传递给我的生产者线程，以便我可以将其放入共享队列中？有可能吗？

主类

public class ProducerConsumerPattern {
    public static void main(String args[]) {

        // create shared object
        BlockingQueue sharedQueue = new LinkedBlockingQueue();

        // create Producer and Consumer Thread
        Thread prodThread = new Thread(new Producer(sharedQueue));
        Thread consThread = new Thread(new Consumer(sharedQueue));

        // start producer and Consumer thread
        prodThread.start();
        consThread.start();
    }
}

消费类

class Consumer implements Runnable {
    private final BlockingQueue sharedQueue;

    public Consumer (BlockingQueue sharedQueue) {
        this.sharedQueue = sharedQueue;
    }

    @Override
    public void run() {
        while(true) {
            try {
                System.out.println("Consumed: "+ sharedQueue.take());
            } catch (InterruptedException ex) {
                Logger.getLogger(Consumer.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    }
}

生产者类

class Producer implements Runnable {
    private final BlockingQueue sharedQueue;

    public Producer(BlockingQueue sharedQueue) {
        this.sharedQueue = sharedQueue;
    }

    @Override
    public void run() {
        // I don't want to write in the queue the counter values.
        // I want to put my own values, when I receive them from outside **
        for (int i=0; i<10; i++) {
            try {
                System.out.println("Produced: " + i);
                sharedQueue.put(i);
            } catch (InterruptedException ex) {
                Logger.getLogger(Producer.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    }
}

我可以通过@RestController和@RequestMapping获取http参数，但是如何获取Producer线程并将这个新值放入队列？

提前致谢！

Answer 1

您需要获取生产者的句柄才能将任何项目推入队列。在生产者中编写一个方法来推送项目：

public class Producer implements Runnable {
    private final BlockingQueue sharedQueue;

    public Producer(BlockingQueue sharedQueue) {
        this.sharedQueue = sharedQueue;
    }

    public void pushItem(int item) throws InterruptedException {
        System.out.println("Produced: " + item);
        sharedQueue.put(item);
    }

    @Override
    public void run() {
        //I don't want to write in the queue the counter values. I want to put my own values, when I receive them from outside **
        for(int i=0; i<10; i++){
            try {
                System.out.println("Produced: " + i);
                sharedQueue.put(i);
            } catch (InterruptedException ex) {
                //Logger.getLogger(Producer.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
    }
}

现在你需要在 main 方法中编写：

public static void main(String[] args) throws InterruptedException {
        //Creating shared object
        BlockingQueue sharedQueue = new LinkedBlockingQueue();

        //Creating Producer and Consumer Thread
        Producer producer = new Producer(sharedQueue);
        Thread prodThread = new Thread(producer);
        Thread consThread = new Thread(new Consumer(sharedQueue));

        //Starting producer and Consumer thread
        prodThread.start();
        consThread.start();

        producer.pushItem(2000);
    }

项目2000 会被主线程推送，但是顺序不保证。示例运行的输出是：

Produced: 0 Produced: 2000 Produced: 1 Produced: 2 Produced: 3 Consumed: 0 Produced: 4 Consumed: 2000 Produced: 5 Produced: 6 Consumed: 1 Produced: 7 Consumed: 2 Produced: 8 Produced: 9 Consumed: 3 Consumed: 4 Consumed: 5 Consumed: 6 Consumed: 7 Consumed: 8 Consumed: 9