高并发：队列Queue

查看Queue接口和类树状结构（F4显示）

高并发队列ConcurrentLinkedQueue

无锁，基于链接节点的无界限线程安全队列（不懂），先进先出，元素不能为null； 无界
1.添加 add() / offer()

阻塞队列BlockingQueue

1.取头元素：poll() 取且删除，peek()取而不删

带优先级的PriorityBlockingQueue

元素必须实现Comparable接口。

带超时时间的DelayQueue

元素必须实现Delayed接口。
使用场景：对缓存超时的数据删除、空闲连接关闭。

//应用
import java.util.concurrent.DelayQueue;
public class WangBa implements Runnable {  
    private DelayQueue queue = new DelayQueue();  
    public boolean yinye =true;  
    public void shangji(String name,String id,int money){  
        Wangmin man = new Wangmin(name, id, 1000 * money + System.currentTimeMillis());  
        System.out.println("网名"+man.getName()+" 身份证"+man.getId()+"交钱"+money+"块,开始上机...");  
        this.queue.add(man);  
    }  

    public void xiaji(Wangmin man){  
        System.out.println("网名"+man.getName()+" 身份证"+man.getId()+"时间到下机...");  
    }  

    @Override  
    public void run() {  
        while(yinye){  
            try {  
                Wangmin man = queue.take();  
                xiaji(man);  
            } catch (InterruptedException e) {  
                e.printStackTrace();  
            }  
        }  
    }  

    public static void main(String args[]){  
        try{  
            System.out.println("网吧开始营业");  
            WangBa siyu = new WangBa();  
            Thread shangwang = new Thread(siyu);  
            shangwang.start();  

            siyu.shangji("路人甲", "123", 1);  
            siyu.shangji("路人乙", "234", 10);  
            siyu.shangji("路人丙", "345", 5);  
        }  
        catch(Exception e){  
            e.printStackTrace();
        }  

    }  
}  
//网民（元素）
import java.util.concurrent.Delayed;
import java.util.concurrent.TimeUnit;

public class Wangmin implements Delayed {  

    private String name;  
    //身份证  
    private String id;  
    //截止时间  
    private long endTime;  
    //定义时间工具类
    private TimeUnit timeUnit = TimeUnit.SECONDS;

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

    public String getName(){  
        return this.name;  
    }  

    public String getId(){  
        return this.id;  
    }  

    /** 
     * 用来判断是否到了截止时间 
     */  
    @Override  
    public long getDelay(TimeUnit unit) { 
        //return unit.convert(endTime, TimeUnit.MILLISECONDS) - unit.convert(System.currentTimeMillis(), TimeUnit.MILLISECONDS);
        return endTime - System.currentTimeMillis();
    }  

    /** 
     * 相互批较排序用 
     */  
    @Override  
    public int compareTo(Delayed delayed) {  
        Wangmin w = (Wangmin)delayed;  
        return this.getDelay(this.timeUnit) - w.getDelay(this.timeUnit) > 0 ? 1:0;  
    }  
}