并发编程复习（八）：队列相关

package cn.lh.queue;import java.util.ArrayList;import java.util.Iterator;import java.util.List;import java.util.Queue;import java.util.concurrent.*;/** * @Author Lee_Hoo * @DATE Created in 2017/9/22 * @Description: ConcurrentLinkedQueue是一个适用于高并发场景下的并发队列，非阻塞，通过无锁方式，实现高并发状态下的高性能，通常它 * 的性能高于BlockingQueue， * 它是一个基于链接节点的无界线程安全队列，先进先出。 * 主要方法：add()和offer()都是加入元素方法，在ConcurrentLinkedQueue中没有区别 *          poll()和peek()都是去元素，区别是前者会删除元素，后者不会 *          BlockingQueue:阻塞队列，有五个实现类 *                ArrayBlockingQueue:内部维护定长数组，没有实现读写分离，生产和消费不能完全并行，可以指定先进先出或者先进后出， *          也叫有界队列。 *                LinkeedBlockingQueue:基于链表的阻塞队列，采用读写分离，从而实现生产和消费完全的并行，是一个无界队列。 *                SynchronousQueue:没有缓冲的队列，生产出的数据会直接被消费者获得被消费 */public class MyQueue {    public static void main(String[] args) throws InterruptedException {        //高性能的无界无阻赛队列：ConcurrentLinkedQueue        Queue q = new ConcurrentLinkedQueue();        q.add("a");        q.offer("b");        q.add("v");        q.add("d");        System.out.println(q.peek());        System.out.println(q.size());        System.out.println(q.poll());        System.out.println(q.size());        //之所以有界，在于构造时就要指定大小        Queue<Object> q1 = new ArrayBlockingQueue(5);        //可以有界也可以无界        //LinkedBlockingQueue<Object> q2 = new LinkedBlockingQueue<>();        LinkedBlockingQueue<Object> q3 = new LinkedBlockingQueue<>(5);        q3.offer("a");        q3.offer("b");        q3.offer("d");        q3.offer("c");        q3.offer("e");        List<Object> list = new ArrayList<>();        q3.drainTo(list,3);        System.out.println(list.size());        //该队列不能添加元素，立即生产立即处理，没有数据缓存，可以这样来理解：生产者和消费者互相等待对方，握手，然后一起离开。       /* SynchronousQueue<Object> ss = new SynchronousQueue<>();        //ss.add("a");//会报错，如果没有线程去take会报错        try {            ss.put(true);        } catch (InterruptedException e) {            e.printStackTrace();        }*/        System.out.println("----------------------------");        //PriorityBlockingQueue:基于优先级的阻塞队列，传入的对象必须实现Comparable接口，内部控制线程同步采用的是公平锁，无界队列        //比较产生的结果如果是负数，那么他的优先级就高        PriorityBlockingQueue<Task> pb = new PriorityBlockingQueue<>();        Task t1 = new Task(1,"张三");        Task t2 = new Task(3,"李四");        Task t3 = new Task(2,"王五");        pb.add(t1);        pb.add(t2);        pb.add(t3);        //排序情况：[Task{id=1, name='张三'}, Task{id=3, name='李四'}, Task{id=2, name='王五'}]        System.out.println(pb);//其实内部存储最先的情况是无序的,没有进行比较排序        //System.out.println(pb.take());//只有当调用take方法只会内部才会进行排序        //System.out.println(pb.remove());//排序        System.out.println(pb.peek());//不排序        //[Task{id=2, name='王五'}, Task{id=3, name='李四'}]，进行了比较排序        System.out.println(pb);    }}

Task类：

package cn.lh.queue;import org.jetbrains.annotations.NotNull;/** * @Author Lee_Hoo * @DATE Created in 2017/9/22 * @Description: */public class Task implements Comparable<Task>{    private int id;    private String name;    public Task(int id, String name) {        this.id = id;        this.name = name;    }    public Task() {    }    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    @Override    public int compareTo(@NotNull Task task) {        return this.id>task.id?1:(this.id<task.id?-1:0);    }    @Override    public String toString() {        return "Task{" +                "id=" + id +                ", name='" + name + '\'' +                '}';    }}

网吧场景详解DelayQueue队列：

网吧类：

package cn.lh.queue;import java.util.concurrent.DelayQueue;/** * @Author Lee_Hoo * @DATE Created in 2017/9/22 * @Description: */public class WangBa implements Runnable{    private DelayQueue<WangMing> queue = new DelayQueue<>();    public boolean yingye = true;    public void shangji(String name,String id,int money){        WangMing wm = new WangMing(id,name,1000*money+System.currentTimeMillis());        System.out.println("网民"+name+"身份证"+id+"交钱"+money+"块"+"开始上机");        this.queue.add(wm);    }    public  void xiaji(WangMing wm){        System.out.println("网名"+wm.getName()+"身份证"+wm.getId()+"下机");    }    @Override    public void run() {        try {            while (yingye){                WangMing man = queue.take();                xiaji(man);            }        }catch (Exception e){            e.printStackTrace();        }    }    public static void main(String[] args) {        try {            System.out.println("开始营业");            WangBa wb = new WangBa();            Thread shangwang = new Thread(wb);            shangwang.start();            wb.shangji("张三","123",1);            wb.shangji("李四","555",10);            wb.shangji("王五","789",5);        }catch (Exception e){            e.printStackTrace();        }    }}

网民类：

package cn.lh.queue;import org.jetbrains.annotations.NotNull;import java.util.concurrent.Delayed;import java.util.concurrent.TimeUnit;/** * @Author Lee_Hoo * @DATE Created in 2017/9/22 * @Description: */public class WangMing implements Delayed {    private String id;    private String name;    private long endTime;    private TimeUnit timeUnit = TimeUnit.SECONDS;    public WangMing(String id, String name, long endTime) {        this.id = id;        this.name = name;        this.endTime = endTime;    }    public String getId() {        return id;    }    public void setId(String id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public long getEndTime() {        return endTime;    }    public void setEndTime(long endTime) {        this.endTime = endTime;    }    @Override    public long getDelay(@NotNull TimeUnit unit) {        return endTime-System.currentTimeMillis();    }    @Override    public int compareTo(@NotNull Delayed o) {        WangMing w = (WangMing) o;        return this.getDelay(this.timeUnit)-w.getDelay(this.timeUnit)>0?1:0;    }}