DelayQueue延迟阻塞队列

1、DelayQueue:

      带有延迟时间的Queue，其中的元素只有当其指定了延迟时间到了，才能够从队列中获取元素。DelayQueue中的元素必须实现Delay接口，DelayQueue是一个没有大小限制的队列，应用场景很多，比如对缓存超时的数据进行移除、任务超时处理、空闲连接关闭等。

2、示例如下：

package net.oschina.tkj.mulitcoding.blockqueue.delayqueue;

import java.util.concurrent.Delayed;
import java.util.concurrent.TimeUnit;

/**
 * 网民,放入延迟的时间队列 DelayQueue里面，元素要实现Delayed接口
 * 
 * @author Freedom
 * 
 */
public class NetPerson implements Delayed {

	private final int id; // 身份证
	private final String name;
	private final long endTime;

	public NetPerson(int id, String name, long endTime) {
		this.id = id;
		this.name = name;
		this.endTime = endTime;
	}

	public int getId() {
		return id;
	}

	public String getName() {
		return name;
	}

	public long getEndTime() {
		return endTime;
	}

	@Override
	public int compareTo(Delayed o) {
		NetPerson p = (NetPerson) o;
		return this.getDelay(TimeUnit.SECONDS) - p.getDelay(TimeUnit.SECONDS) > 0 ? 1
				: -1;
	}

	@Override
	public long getDelay(TimeUnit unit) {
		return endTime - System.currentTimeMillis();
	}

	@Override
	public String toString() {
		return "NetPerson [id=" + id + ", name=" + name + ", endTime="
				+ endTime + "]";
	}

}

package net.oschina.tkj.mulitcoding.blockqueue.delayqueue;

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.DelayQueue;

/**
 * 网吧类，为线程的任务类
 * 
 * @author Freedom
 * 
 */
public class NetBar implements Runnable {

	// 定义一个阻塞的延迟的队列
	private static BlockingQueue<NetPerson> queue = new DelayQueue<>();

	// 登记用户上网的信息
	public void registNetPerson(int id, String name, long money) {
		NetPerson person = new NetPerson(id, name, 1000 * money
				+ System.currentTimeMillis());
		System.out.println("用户：" + person + " 开始上网...");
		queue.add(person);
	}

	/*
	 * 用户下机
	 */
	public void endPlay(NetPerson p) {
		System.out.println("用户：" + p + " 上机时间到了，下机...");
	}

	@Override
	public void run() {
		NetPerson p = null;
		try {
			while (true) {
				p = queue.take();
				endPlay(p);
				Thread.sleep(500);
			}
		} catch (InterruptedException e) {
			e.printStackTrace();
		}

	}

	/**
	 * 主函数
	 * 
	 * @param args
	 */
	public static void main(String[] args) {

		System.out.println("新的一天，网吧营业开始...");
		NetBar bar = new NetBar();
		Thread t1 = new Thread(bar);
		bar.registNetPerson(411, "张三", 10);
		bar.registNetPerson(342, "李四", 5);
		bar.registNetPerson(675, "王五", 3);

		t1.start();

	}

}