code:

 

import java.util.concurrent.ArrayBlockingQueue;

import java.util.concurrent.BlockingQueue;

public class Queue {

        public static void main(String[] args)  {

                BlockingQueue bqueue = new ArrayBlockingQueue(20);

                for (int i = 0; i < 30; i++) {

                    

                        try {

       bqueue.put(i);

      } catch (InterruptedException e) {

       // TODO Auto-generated catch block

       e.printStackTrace();

      }

                        System.out.println("add items into queue:" + i);

                        if (bqueue.size()==20) {

                         for (int j = 0; j<5;j++) {

                             System.out.println("remove items from queue:" + bqueue.remove());

                            }

                        }

                }

               

                System.out.println("program is over");

        }

}

说明：队列满，线程将被阻塞，所以只有加入了出队操作程序才会被执行到最后一行----System.out.println("program is over");