Java 阻塞队列 BlockingQueue

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阻塞队列：只是队列的拓展，传统队列当满的时候会抛出异常，而阻塞队列会一直等待，不会报错，当然，里面包含的方法如下：

抛出异常特殊值阻塞超时插入add(e)offer(e)put(e)offer(e, time, unit)移除remove()poll()take()poll(time, unit)检查element()peek()不可用不可用

我们发现添加方法有四种，我们这里分别演示一下效果，

add(e)

public class QueueDemo {public static void main(String[] args) throws InterruptedException {ArrayBlockingQueue<Integer> queue = new ArrayBlockingQueue<Integer>(20);for (int i = 0; i < 30; i++) {queue.add(i);// queue.offer(i);// queue.put(i);System.out.println("add number is --->" + i);}System.out.println("END");}}

结果：

add number is --->0add number is --->1add number is --->2add number is --->3add number is --->4add number is --->5add number is --->6add number is --->7add number is --->8add number is --->9add number is --->10add number is --->11add number is --->12add number is --->13add number is --->14add number is --->15add number is --->16add number is --->17add number is --->18add number is --->19Exception in thread "main" java.lang.IllegalStateException: Queue fullat java.util.AbstractQueue.add(Unknown Source)at java.util.concurrent.ArrayBlockingQueue.add(Unknown Source)at com.yonyou.thread.QueueDemo.main(QueueDemo.java:9)

开辟了size为20的队列，但是添加进去30个Integer对象，则超过临界区大小，抛出异常。

queue.offer(i);

add number is --->0add number is --->1add number is --->2add number is --->3add number is --->4add number is --->5add number is --->6add number is --->7add number is --->8add number is --->9add number is --->10add number is --->11add number is --->12add number is --->13add number is --->14add number is --->15add number is --->16add number is --->17add number is --->18add number is --->19add number is --->20add number is --->21add number is --->22add number is --->23add number is --->24add number is --->25add number is --->26add number is --->27add number is --->28add number is --->29END

结果正常输出，该方法放弃大小限制，无限制容量扩展。

到达临界区放不进去了。。。队列处于阻塞状态。。。等待有空闲空间。

queue.offer(i, 2000, TimeUnit.MILLISECONDS);

结果也不会受到size大小限制，会根据我们提前设置好的2s 依次入队结果没有影响。

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