问题描述

帮忙看看这个程序的输出？

package thread.forkjoinpool;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.PriorityBlockingQueue;
import java.util.concurrent.TimeUnit;

public class Main3 {

static class Event implements Comparable<Event>{    private int id;    private int priority;    /**     * @param id     * @param priority     */    public Event(int id int priority) {        this.id = id;        this.priority = priority;    }    public int compareTo(Event o) {        if(o==null) throw new IllegalArgumentException();        if(this.priority>o.priority) return 1;        else if(this.priority<o.priority) return -1;        return 0;    }    /* (non-Javadoc)     * @see java.lang.Object#toString()     */    @Override    public String toString() {        return ""Event [id="" + id + "" priority="" + priority + ""]"";    }}static class Run implements Runnable{    private PriorityBlockingQueue<Event> queue;    /**     * @param queue     */    public Run(PriorityBlockingQueue<Event> queue) {        this.queue = queue;    }    public void run() {        for (int i = 10; i > 0; i--) {            Event event = new Event(i i);            queue.add(event);        }    }}public static void main(String[] args) {    PriorityBlockingQueue<Event> queue = new PriorityBlockingQueue<Event>();    ExecutorService newCachedThreadPool = Executors.newCachedThreadPool();    Run run = new Run(queue);    newCachedThreadPool.execute(run);    newCachedThreadPool.shutdown();    try {        boolean awaitTermination = newCachedThreadPool.awaitTermination(10 TimeUnit.SECONDS);        if(awaitTermination){            System.out.println(""任务结束"");        }    } catch (InterruptedException e) {        e.printStackTrace();    }    System.out.println(queue);    for (int i = 0; i < queue.size(); i++) {        System.out.println(queue.size());        Event poll = queue.poll();        System.out.println(queue.size());        System.out.println(""结果：""+poll);    }}

}

任务结束
[Event [id=1 priority=1] Event [id=2 priority=2] Event [id=5 priority=5] Event [id=4 priority=4] Event [id=3 priority=3] Event [id=9 priority=9] Event [id=6 priority=6] Event [id=10 priority=10] Event [id=7 priority=7] Event [id=8 priority=8]]
10
9
结果：Event [id=1 priority=1]
9
8
结果：Event [id=2 priority=2]
8
7
结果：Event [id=3 priority=3]
7
6
结果：Event [id=4 priority=4]
6
5
结果：Event [id=5 priority=5]

这个为什么只输出了5个记录？但是集合的大小是对的

解决方案

 for (int i = 0; i < queue.size(); i++) {        System.out.println(queue.size());        Event poll = queue.poll();//每次poll一个，queue长度在不断改变，当移除5个，的时候queue.size()就只有5了，而这时候i也是5，for条件(i<queue.size())不成立，退出循环，所以就移除了5个，也就是一半        System.out.println(queue.size());        System.out.println(""结果：""+poll);    }    改成    for (int i = queue.size()-1; i >=0; i--) {        System.out.println(queue.size());        Event poll = queue.poll();        System.out.println(queue.size());        System.out.println(""结果：""+poll);    }        或者        while(queue.size()>0){        System.out.println(queue.size());        Event poll = queue.poll();        System.out.println(queue.size());        System.out.println(""结果：""+poll);    }        如果有帮助，记得采纳一下哦

解决方案二：
帮忙看看这段程序啊

解决方案三：
调试下，是不是主线程先退出了。