java阻塞队列以及非阻塞队列

来源：互联网发布：java布局思想编辑：程序博客网时间：2024/05/16 04:58

1.阻塞队列：是线程安全的
队列满后，如果没有消费者消费队列，那么生存者会阻塞，除非通过
blockingQueue.offer("an apple",5,TimeUnit.SECONDS);//队列满了，指定时间后，不再阻塞

对列空了，如果没有生产者生产队列，那么消费者会阻塞，除非通过
blockingQueue.poll(1, TimeUnit.SECONDS); //队列空时，指定阻塞时间后返回，不会一直阻塞

public class BlockQueueDemo {    private static BlockingQueue blockingQueue = new LinkedBlockingDeque(2);//使用了CAS，lock以及lock.condition的await(),signal（） 有两个condition    static class Producer implements Runnable {        private String name;        public Producer(String name) {            this.name = name;        }        public void run() {            try {                System.out.println(name + " start produce");                blockingQueue.put("an apple");//                blockingQueue.offer("an apple",5,TimeUnit.SECONDS);//队列满了，指定时间后，不再阻塞                System.out.println(name + " end produce");            } catch (InterruptedException e) {                e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.            }            //To change body of implemented methods use File | Settings | File Templates.        }    }    static class Consumer implements Runnable {        private String name;        public Consumer(String name) {            this.name = name;        }        public void run() {            try {                System.out.println(name + " start consumer");//                blockingQueue.take();     //队列空了，会一直阻塞，                blockingQueue.poll(1, TimeUnit.SECONDS); //队列空时，指定阻塞时间后返回，不会一直阻塞                System.out.println(name + " end consumer");            } catch (InterruptedException e) {                e.printStackTrace();  //To change body of catch statement use File | Settings | File Templates.            }        }    }    public static void main(String[] args) {        Producer producer1 = new Producer("producer1");        Producer producer2 = new Producer("producer2");        ExecutorService executorService = Executors.newCachedThreadPool();        executorService.submit(producer1);        executorService.submit(producer2);        executorService.submit(producer1);        Consumer consumer = new Consumer("consumer1");        executorService.submit(consumer);    }}

2.非阻塞队列：是线程安全的

public class NoBlockQueue {    private static ConcurrentLinkedQueue<Integer> concurrentLinkedQueue = new ConcurrentLinkedQueue<Integer>();//使用了CAS原语    public static void main(String[] args) {        ExecutorService executorService = Executors.newFixedThreadPool(2);        executorService.submit(new Producer("producer1"));        executorService.submit(new Producer("producer2"));        executorService.submit(new Producer("producer3"));        executorService.submit(new Consumer("consumer1"));    }    static class Producer implements Runnable {        private String name;        public Producer(String name) {            this.name = name;        }        public void run() {            for (int i = 1; i < 10; ++i) {                System.out.println(name+ " start producer " + i);                concurrentLinkedQueue.add(i);                System.out.println(name+"end producer " + i);            }        }    }    static class Consumer implements Runnable {        private String name;        public Consumer(String name) {            this.name = name;        }        public void run() {            for (int i = 0; i < 10; ++i) {                System.out.println(name+" start Consumer " + i);                System.out.println(concurrentLinkedQueue.poll());                System.out.println(name+" end Consumer " + i);            }        }    }}

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