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);
}
}

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 + '\'' +
'}';
}
}

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();
}
}
}

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;
}
}