Java wait和notifyAll实现简单的阻塞队列

import java.util.concurrent.atomic.AtomicInteger;/** * @author lhd */public class BlockQueue {	/**  * 生产者锁对象  */	private final Object addLock = new Object();	/**  * 消费者锁对象  */	private final Object deleteLock = new Object();	/**  * 队列总大小  */	private final Integer size = 30;	/**  * 数据存放  */	private Object[] queue = new Object[size];	/**  * 存放的数量,使用AtomicInteger是因为普通的int递增递减操作会存在非原子性的问题，会使数量异常  */	private AtomicInteger count = new AtomicInteger(0);	/**  * 生产  * @param o 对象  */	public void add(Object o) {		//获取生产锁,wait方法必须获取到对象锁后才可以调用，否则抛出异常		synchronized (addLock){			//判断是否超过队列大小,超过则进入等待			while (count.get() >= size){				try {					addLock.wait();				}				catch (InterruptedException e) {					e.printStackTrace();				}			}			//存放一个			queue[count.get()] = o;			//递增			int i = count.incrementAndGet();			//打印一下日志			String name = Thread.currentThread().getName();			System.out.println(name + "生产了一个，现有数量" + i);		}		//如果队列有数据，则调用notifyAll唤醒消费者		if (count.get() >= 1){			//notifyAll、notify都需要先获取对象锁,否则会抛出异常			synchronized (deleteLock){				deleteLock.notifyAll();			}		}	}	/**  * 消费  * @return  */	public Object poll(){		Object o;		//先获取对象锁，和生产者类似		synchronized (deleteLock){			//队列里没有数据则等待			while (count.get() <= 0){				try {					deleteLock.wait();				}				catch (InterruptedException e) {					e.printStackTrace();				}			}			//获取数据			o = queue[count.get()];			//递减			int i = count.decrementAndGet();			String name = Thread.currentThread().getName();			System.out.println(name + "消费了一个，现有数量" + i);		}		//如果队列没有满，则可以唤醒生产者		if (count.get() < size){			//需要先获取到锁			synchronized (addLock){				addLock.notifyAll();			}		}		return o;	}	/**  * 简单的测试  * @param args  */	public static void main(String[] args) {		BlockQueue blockQueue = new BlockQueue();		Thread t1 = new Thread(()-> {			while (true){				blockQueue.add(new Object());			}		}		);		Thread t2 = new Thread(()-> {			while (true){				blockQueue.add(new Object());			}		}		);		Thread t3 = new Thread(()-> {			while (true){				blockQueue.add(new Object());			}		}		);		Thread t4 = new Thread(()-> {			while (true){				blockQueue.poll();			}		}		);		Thread t5 = new Thread(()-> {			while (true){				blockQueue.poll();			}		}		);		Thread t6 = new Thread(()-> {			while (true){				blockQueue.poll();			}		}		);		t1.start();		t2.start();		t3.start();		t4.start();		t5.start();		t6.start();	}}

/** * @author lhd */public class JoinTest { public static void main(String[] args) throws InterruptedException {  Thread t1 = new Thread(() -> System.out.println(1));  Thread t2 = new Thread(()-> System.out.println(2));  Thread t3 = new Thread(()-> System.out.println(3));  t1.start();  t1.join();  t2.start();  t2.join();  t3.start();  t3.join(); }}