java多线程实现简单队列

最新推荐文章于 2022-09-12 10:07:39 发布

转载最新推荐文章于 2022-09-12 10:07:39 发布 · 176 阅读

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原文链接：http://www.cnblogs.com/dquery/p/6395553.html

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#java

本文通过实现一个具备容量限制的队列类，演示了如何使用synchronized关键字和wait/notify方法来实现线程间的同步。当队列满时，新增元素的线程将被阻塞，直到其他线程从中取出元素。

　　1.创建Queue.java

public class Queue {
	
	private LinkedList<Object> list = new LinkedList<Object>() ;
	
	private final int minSize = 0 ; ;
	
	private final int maxSize ;
	
	private AtomicInteger count = new AtomicInteger(0) ;
	
	public Queue(int size){
		this.maxSize = size ;
	}
	private final Object lock = new Object() ;
	
	public void put(Object o){
		synchronized(lock){
			while(size() == this.maxSize){
				try {
					lock.wait();
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
			list.add(o) ;
			//计数器增加
			count.incrementAndGet() ;
			//通知唤醒
			lock.notify();
		}
	}
	
	
	private int size(){
		return count.get() ;
	}
	
	public Object take(){
		Object res = null ;
		synchronized(lock){
			while(size() == this.minSize){
				try {
					lock.wait();
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
			}
			res = list.removeFirst();
			//计数器减1
			count.decrementAndGet() ;
			lock.notify();
		}
		return res ;
		
	}
	
	public static void main(String[] args) {
		
		final Queue mq = new Queue(3) ;
		
		mq.put("a");
		mq.put("b");
		mq.put("c");
		
		new Thread(new Runnable() {
			
			@Override
			public void run() {
				mq.put("g");
				System.out.println("put1 secceseful");
				mq.put("f");
				System.out.println("put2 secceseful");
			}
		}).start();
		
		
		new Thread(new Runnable() {
			
			@Override
			public void run() {
				System.out.println("take value = "+mq.take() );
			}
		}).start();
		
		
	}
}

　　运行结果如下：