详解Java阻塞队列(BlockingQueue)的实现原理

package MyThread;

import java.util.Random;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.TimeUnit;

public class BlockingQueueTest {
  //生产者
  public static class Producer implements Runnable{
    private final BlockingQueue<Integer> blockingQueue;
    private volatile boolean flag;
    private Random random;

    public Producer(BlockingQueue<Integer> blockingQueue) {
      this.blockingQueue = blockingQueue;
      flag=false;
      random=new Random();

    }
    public void run() {
      while(!flag){
        int info=random.nextInt(100);
        try {
          blockingQueue.put(info);
          System.out.println(Thread.currentThread().getName()+" produce "+info);
          Thread.sleep(50);
        } catch (InterruptedException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
        }        
      }
    }
    public void shutDown(){
      flag=true;
    }
  }
  //消费者
  public static class Consumer implements Runnable{
    private final BlockingQueue<Integer> blockingQueue;
    private volatile boolean flag;
    public Consumer(BlockingQueue<Integer> blockingQueue) {
      this.blockingQueue = blockingQueue;
    }
    public void run() {
      while(!flag){
        int info;
        try {
          info = blockingQueue.take();
          System.out.println(Thread.currentThread().getName()+" consumer "+info);
          Thread.sleep(50);
        } catch (InterruptedException e) {
          // TODO Auto-generated catch block
          e.printStackTrace();
        }        
      }
    }
    public void shutDown(){
      flag=true;
    }
  }
  public static void main(String[] args){
    BlockingQueue<Integer> blockingQueue = new LinkedBlockingQueue<Integer>(10);
    Producer producer=new Producer(blockingQueue);
    Consumer consumer=new Consumer(blockingQueue);
    //创建5个生产者，5个消费者
    for(int i=0;i<10;i++){
      if(i<5){
        new Thread(producer,"producer"+i).start();
      }else{
        new Thread(consumer,"consumer"+(i-5)).start();
      }
    }

    try {
      Thread.sleep(1000);
    } catch (InterruptedException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    producer.shutDown();
    consumer.shutDown();

  }
}

public ArrayBlockingQueue(int capacity, boolean fair) {

    if (capacity <= 0)
      throw new IllegalArgumentException();
    //创建数组  
    this.items = new Object[capacity];
    //创建锁和阻塞条件
    lock = new ReentrantLock(fair);  
    notEmpty = lock.newCondition();
    notFull = lock.newCondition();
  }
//添加元素的方法
public void put(E e) throws InterruptedException {
    checkNotNull(e);
    final ReentrantLock lock = this.lock;
    lock.lockInterruptibly();
    try {
      while (count == items.length)
        notFull.await();
      //如果队列不满就入队
      enqueue(e);
    } finally {
      lock.unlock();
    }
  }
 //入队的方法
 private void enqueue(E x) {
    final Object[] items = this.items;
    items[putIndex] = x;
    if (++putIndex == items.length)
      putIndex = 0;
    count++;
    notEmpty.signal();
  }
 //移除元素的方法
 public E take() throws InterruptedException {
    final ReentrantLock lock = this.lock;
    lock.lockInterruptibly();
    try {
      while (count == 0)
        notEmpty.await();
      return dequeue();
    } finally {
      lock.unlock();
    }
  }
 //出队的方法
 private E dequeue() {
    final Object[] items = this.items;
    @SuppressWarnings("unchecked")
    E x = (E) items[takeIndex];
    items[takeIndex] = null;
    if (++takeIndex == items.length)
      takeIndex = 0;
    count--;
    if (itrs != null)
      itrs.elementDequeued();
    notFull.signal();
    return x;