BlockingQueue 四组API

# BlockingQueue 四组API

1. 抛出异常

2. 不抛异常

3. 阻塞等待

4. 超时等待

方式	抛出异常	有返回值	阻塞等待	超时等待
添加	add()	offer()	put()	offer(...)
移除	remove()	poll()	take()	poll(..)
判断队列首	element()	peek()

package com.pa.test.JUC.queue;

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.TimeUnit;

public class BlockingQueueTest {
    public static void main(String[] args) throws InterruptedException {
        //test1();
        //test2();
        //test3();
        test4();
    }

    /**
     * 抛出异常
     */
    public static void test1(){
        //设置大小 3个
        ArrayBlockingQueue arrayBlockingQueue = new ArrayBlockingQueue<>(3);
        System.out.println(arrayBlockingQueue.add("a"));
        System.out.println(arrayBlockingQueue.add("b"));
        System.out.println(arrayBlockingQueue.add("c"));
        //添加第四个会有异常 java.lang.IllegalStateException: Queue full
        //System.out.println(arrayBlockingQueue.add("d"));

        System.out.println("===============");
        System.out.println(arrayBlockingQueue.remove());
        //检测队列首元素
        System.out.println(arrayBlockingQueue.element());
        System.out.println(arrayBlockingQueue.remove());
        System.out.println(arrayBlockingQueue.remove());
        //java.util.NoSuchElementException
        //System.out.println(arrayBlockingQueue.remove());
    }

    /**
     * 不抛异常 有返回值
     */
    public static void test2(){
        ArrayBlockingQueue arrayBlockingQueue = new ArrayBlockingQueue<>(3);

        System.out.println(arrayBlockingQueue.offer("a"));
        System.out.println(arrayBlockingQueue.offer("b"));
        System.out.println(arrayBlockingQueue.offer("c"));
        //检测队列首元素
        System.out.println(arrayBlockingQueue.peek());
        //会返回false
        System.out.println(arrayBlockingQueue.offer("d"));
        System.out.println("==================");
        System.out.println(arrayBlockingQueue.poll());
        System.out.println(arrayBlockingQueue.poll());
        System.out.println(arrayBlockingQueue.poll());
        //返回 null
        System.out.println(arrayBlockingQueue.poll());
    }

    /**
     * 阻塞等待 （一直阻塞)
     */
    public static void test3() throws InterruptedException {
        ArrayBlockingQueue arrayBlockingQueue = new ArrayBlockingQueue<>(3);

        arrayBlockingQueue.put("a");
        arrayBlockingQueue.put("b");
        arrayBlockingQueue.put("c");
        //会一直阻塞 程序不会停
        //arrayBlockingQueue.put("d");
        System.out.println("==================");
        System.out.println(arrayBlockingQueue.take());
        System.out.println(arrayBlockingQueue.take());
        System.out.println(arrayBlockingQueue.take());
        //会一直阻塞 程序不会停
        //System.out.println(arrayBlockingQueue.take());
    }

    /**
     * 阻塞 等待 超时
     */
    public static void test4() throws InterruptedException {
        ArrayBlockingQueue arrayBlockingQueue = new ArrayBlockingQueue<>(3);

        System.out.println(arrayBlockingQueue.offer("a"));
        System.out.println(arrayBlockingQueue.offer("b"));
        System.out.println(arrayBlockingQueue.offer("c"));
        //超时2秒 自动放弃
        System.out.println(arrayBlockingQueue.offer("d",2, TimeUnit.SECONDS));
        System.out.println("==================");
        System.out.println(arrayBlockingQueue.poll());
        System.out.println(arrayBlockingQueue.poll());
        System.out.println(arrayBlockingQueue.poll());
        //超时2秒 自动放弃
        System.out.println(arrayBlockingQueue.poll(2,TimeUnit.SECONDS));
    }
}