java.util.concurrent 之四：LinkedBlockingQueue
并发库中的BlockingQueue是一个比较好玩的类，顾名思义，就是阻塞队列。该类主要提供了两个方法put()和take()，前者将一个对象放到队列尾部，如果队列已经满了，就等待直到有空闲节点；后者从head取一个对象，如果没有对象，就等待直到有可取的对象。

package test;import java.util.concurrent.BlockingQueue;import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.LinkedBlockingQueue;public class MyBlockingQueue extends Thread{public static BlockingQueue<String> queue=new LinkedBlockingQueue<String>(3);private int index;public MyBlockingQueue(int i){this.index=i;}public void run(){try{queue.put(String.valueOf(this.index));System.out.println("put {"+this.index+"} into queue!");}catch(Exception e){e.printStackTrace();}}public static void main(String args[]){ExecutorService service=Executors.newCachedThreadPool();for( int i=0; i<10; i++){service.submit(new MyBlockingQueue(i));}Thread thread = new Thread(){public void run(){try{while(true){Thread.sleep((int)(Math.random()*1000));if(MyBlockingQueue.queue.isEmpty()) break;String str=MyBlockingQueue.queue.take();System.out.println("take {" + str+"} out of queue!");}}catch(Exception e){e.printStackTrace();}}};service.submit(thread);service.shutdown();}}

put {0} into queue!put {1} into queue!put {3} into queue!take {0} out of queue!put {2} into queue!take {1} out of queue!put {7} into queue!take {3} out of queue!put {5} into queue!take {2} out of queue!put {4} into queue!take {7} out of queue!put {6} into queue!put {9} into queue!take {5} out of queue!take {4} out of queue!put {8} into queue!take {6} out of queue!take {9} out of queue!take {8} out of queue!