java 延时队列使用

import java.time.LocalDateTime;

import java.time.format.DateTimeFormatter;

import java.util.concurrent.DelayQueue;

import java.util.concurrent.Delayed;

import java.util.concurrent.TimeUnit;

 

/**

 * @description: 延时队列测试

 * @author: hh

 */

public class DelayedQueneTest {

 

    public static void main(String[] args) throws InterruptedException {

        Item item1 = new Item("item1", 5, TimeUnit.SECONDS);

        Item item2 = new Item("item2",10, TimeUnit.SECONDS);

        Item item3 = new Item("item3",15, TimeUnit.SECONDS);

        DelayQueue<Item> queue = new DelayQueue<>();

        queue.put(item1);

        queue.put(item2);

        queue.put(item3);

        System.out.println("begin time:" + LocalDateTime.now().format(DateTimeFormatter.ISO_LOCAL_DATE_TIME));

        for (int i = 0; i < 3; i++) {

            Item take = queue.take();

            System.out.format("name:{%s}, time:{%s} ",take.name, LocalDateTime.now().format(DateTimeFormatter.ISO_DATE_TIME));

        }

    }

 

}

 

class Item implements Delayed{

    /* 触发时间*/

    private long time;

    String name;

 

    public Item(String name, long time, TimeUnit unit) {

        this.name = name;

        this.time = System.currentTimeMillis() + (time > 0? unit.toMillis(time): 0);

    }

 

    @Override

    public long getDelay(TimeUnit unit) {

        return time - System.currentTimeMillis();

    }

 

    @Override

    public int compareTo(Delayed o) {

        Item item = (Item) o;

        long diff = this.time - item.time;

        if (diff <= 0) {// 改成>=会造成问题

            return -1;

        }else {

            return 1;

        }

    }

 

    @Override

    public String toString() {

        return "Item{" +

                "time=" + time +

                ", name='" + name + ''' +

                '}';

    }

}

 

 

 

转自： https://www.cnblogs.com/hhan/p/10678466.html