BlockingQueue

BlockingQueue要求当队列为空或满时就会阻塞线程

方式	有返回值，抛出异常	有返回值，不抛出异常	没有返回值，阻塞等待	有返回值，超时等待
添加	add()	offer()	put()	offer(..)
移除	remove()	poll()	take()	poll(..)
检测队首元素	element()	peek()	-	-

public static void main(String[] args) {
        // 3代表队列的容量
        BlockingQueue<String> objects = new ArrayBlockingQueue<>(3);
        objects.add("a");
        objects.add("c");
        objects.add("b");
        //objects.add("d"); 报错Queue full
        //System.out.println(objects.offer("d"));输出false
        // objects.put("d"); 阻塞等待
        //objects.offer("d",2, TimeUnit.SECONDS);等待两秒，超时放弃.2代表时间，TimeUtil.Seconds代表时间单位
        System.out.println(objects.remove());
        System.out.println(objects.remove());
        System.out.println(objects.remove());
        //System.out.println(objects.remove());//报错NoSuchElementException
        //System.out.println(objects.poll()); 输出null
        //objects.take();阻塞等待
        //objects.poll(2,TimeUnit.SECONDS);等待两秒，超时放弃
       

    }

SynchronousQueue 同步队列

没有容量，放完必须取。

public class BlockingQueueTest {
    public static void main(String[] args) {
        BlockingQueue<String > objects = new SynchronousQueue<>();

        new Thread(()->{

            try {
                System.out.println(Thread.currentThread().getName()+"put");
                objects.put(String.valueOf(1));
                System.out.println(Thread.currentThread().getName()+"put");
                objects.put(String.valueOf(2));
                System.out.println(Thread.currentThread().getName()+"put");
                objects.put(String.valueOf(2));

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

        }).start();
        new Thread(()->{
            try {
                Thread.sleep(2);
                System.out.println(Thread.currentThread().getName()+"get"+objects.take());
                Thread.sleep(2);
                System.out.println(Thread.currentThread().getName()+"get"+objects.take());
                Thread.sleep(2);
                System.out.println(Thread.currentThread().getName()+"get"+objects.take());
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }).start();

    }

}
Thread-0put
Thread-1get1
Thread-0put
Thread-1get2
Thread-0put
Thread-1get2