Java并发包相关组件(2)

1. Exchanger

用于线程之间的数据交换

//生产者生产出固定的数量后与消费者的产品容器进行交换
class Producer implements Runnable{
    private Queue<String> products;
    private Exchanger<Queue> exchanger;
    private int maxNum;
    private int id;
    private static int allId;

    public Producer(Queue<String> products,Exchanger exchanger,int maxNum) {
        this.products = products;
        this.exchanger = exchanger;
        this.maxNum = maxNum;
        this.id = allId++;
    }

    @Override
    public void run() {
        try {
            while (!Thread.interrupted()){
                synchronized (Producer.class){
                    while (products.size() >= this.maxNum){
                        this.products = exchanger.exchange(products);
                    }
                }
                System.out.println("生产者" + this.id + "号开始生产");
                TimeUnit.MILLISECONDS.sleep(new Random().nextInt(1000) + 500);
                products.offer("产品-----" + "生产者" + this.id + "号");
                System.out.println("生产者" + this.id + "生产完毕");
            }
        }
        catch (Exception e){
            e.printStackTrace();
        }
    }
}

//消费者的产品队列为空的时候与生产者的产品队列进行交换
class Consumer implements Runnable{
    private Queue<String> products;
    private Exchanger<Queue> exchanger;
    private int id;
    private static int allId;

    public Consumer(Queue<String> products,Exchanger exchanger) {
        this.products = products;
        this.exchanger = exchanger;
        this.id = allId++;
    }

    @Override
    public void run() {
        while (!Thread.interrupted()){
            try {
                //保证只有一个线程会进行队列的交换
                synchronized (Consumer.class){
                    while (products.isEmpty()){
                        exchanger.exchange(products);
                    }
                    System.out.println("消费者" + this.id + "开始消费" + products.poll());
                }

                TimeUnit.MILLISECONDS.sleep(new Random().nextInt(1000) + 500);
                System.out.println("消费者" + this.id + "消费结束");
            }
            catch (Exception e){
                e.printStackTrace();
            }
        }
    }
}

//main
class Main{
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        ExecutorService executorService = Executors.newFixedThreadPool(4);
        Queue<String> producerList = new LinkedList<>();
        Queue<String> consumerList = new LinkedList<>();
        Exchanger exchanger = new Exchanger();

        for(int i = 0;i < 2;i++){
            executorService.submit(new Producer(producerList,exchanger,5));
            executorService.submit(new Consumer(consumerList,exchanger));
        }

    }
}