ICode9

精准搜索请尝试: 精确搜索
首页 > 其他分享> 文章详细

阻塞队列

2022-04-18 22:35:17  阅读:168  来源: 互联网

标签:poll 队列 System 阻塞 put println blockingQueue out


BlockingQueue

方式 抛出异常 有返回值,不抛出异常 阻塞等待 超时等待
添加 boolean add(E e) boolean offer(E e) void put(E e) boolean offer(E e, long timeout, TimeUnit unit)
移除 E remove() E poll() E take() E poll(long timeout, TimeUnit unit)
检测队首元素 E element() E peek() - -
    /*
    抛出异常
     */
    public static void test1() {
        // 参数:队列的大小
        ArrayBlockingQueue<Object> blockingQueue = new ArrayBlockingQueue<>(3);

        System.out.println(blockingQueue.add("a"));
        System.out.println(blockingQueue.add("b"));
        System.out.println(blockingQueue.add("c"));

        // java.lang.IllegalStateException: Queue full 抛出异常!
//        System.out.println(blockingQueue.add("d"));

        System.out.println("=========================");
        System.out.println(blockingQueue.remove());
        System.out.println(blockingQueue.element());//查看队首元素是谁
        System.out.println(blockingQueue.remove());
        System.out.println(blockingQueue.remove());

        // java.util.NoSuchElementException
//        System.out.println(blockingQueue.remove());
    }

    /*
    有返回值,没有异常
     */
    public static void test2() {
        // 参数:队列的大小
        ArrayBlockingQueue<Object> blockingQueue = new ArrayBlockingQueue<>(3);

        System.out.println(blockingQueue.offer("a"));
        System.out.println(blockingQueue.offer("b"));
        System.out.println(blockingQueue.offer("c"));

//        System.out.println(blockingQueue.offer("d"));//false 不抛出异常

        System.out.println(blockingQueue.peek());
        System.out.println("===========================");
        System.out.println(blockingQueue.poll());
        System.out.println(blockingQueue.poll());
        System.out.println(blockingQueue.poll());
        System.out.println(blockingQueue.poll());//null 不抛出异常
    }

    /*
    等待,阻塞(一直阻塞)
     */
    public static void test3() throws InterruptedException {
        // 参数:队列的大小
        ArrayBlockingQueue<Object> blockingQueue = new ArrayBlockingQueue<>(3);

        blockingQueue.put("a");
        blockingQueue.put("b");
        blockingQueue.put("c");
//        blockingQueue.put("d");//队列没有位置,一直阻塞
        System.out.println(blockingQueue.take());
        System.out.println(blockingQueue.take());
        System.out.println(blockingQueue.take());
        System.out.println(blockingQueue.take());
    }
    /*
    等待,阻塞(等待超时)
     */
    public static void test4() throws InterruptedException {
        // 参数:队列的大小
        ArrayBlockingQueue<Object> blockingQueue = new ArrayBlockingQueue<>(3);

        blockingQueue.offer("a");
        blockingQueue.offer("b");
        blockingQueue.offer("c");
//        blockingQueue.offer("d",2, TimeUnit.SECONDS);//等待超过两秒就退出

        System.out.println(blockingQueue.poll());
        System.out.println(blockingQueue.poll());
        System.out.println(blockingQueue.poll());
        System.out.println(blockingQueue.poll(2, TimeUnit.SECONDS));//等待超过两秒就退出
    }

SynchronousQueue

/*
同步队列
和其他的BlockingQueue不一样,SynchronousQueue不存储元素
put了一个元素,必须从里面先take取出来,否则不能再put进去取!
 */
public class SynchronousQueueDemo {
    public static void main(String[] args) {
        BlockingQueue<String> blockingQueue = new SynchronousQueue<>();//同步队列

        new Thread(() -> {
            try {
                System.out.println(Thread.currentThread().getName() + " put 1");
                blockingQueue.put("1");
                System.out.println(Thread.currentThread().getName() + " put 2");
                blockingQueue.put("2");
                System.out.println(Thread.currentThread().getName() + " put 3");
                blockingQueue.put("3");
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }, "T1").start();

        new Thread(() -> {
            try {
                TimeUnit.SECONDS.sleep(2);
                System.out.println(Thread.currentThread().getName() + "=>" + blockingQueue.take());
                TimeUnit.SECONDS.sleep(2);
                System.out.println(Thread.currentThread().getName() + "=>" + blockingQueue.take());
                TimeUnit.SECONDS.sleep(2);
                System.out.println(Thread.currentThread().getName() + "=>" + blockingQueue.take());

            } catch (InterruptedException e) {
                e.printStackTrace();
            }

        }, "T2").start();
    }
}

标签:poll,队列,System,阻塞,put,println,blockingQueue,out
来源: https://www.cnblogs.com/singob/p/16163141.html

本站声明: 1. iCode9 技术分享网(下文简称本站)提供的所有内容,仅供技术学习、探讨和分享;
2. 关于本站的所有留言、评论、转载及引用,纯属内容发起人的个人观点,与本站观点和立场无关;
3. 关于本站的所有言论和文字,纯属内容发起人的个人观点,与本站观点和立场无关;
4. 本站文章均是网友提供,不完全保证技术分享内容的完整性、准确性、时效性、风险性和版权归属;如您发现该文章侵犯了您的权益,可联系我们第一时间进行删除;
5. 本站为非盈利性的个人网站,所有内容不会用来进行牟利,也不会利用任何形式的广告来间接获益,纯粹是为了广大技术爱好者提供技术内容和技术思想的分享性交流网站。

专注分享技术,共同学习,共同进步。侵权联系[81616952@qq.com]

Copyright (C)ICode9.com, All Rights Reserved.

ICode9版权所有