延时队列DelayQueue

自定义延迟队列

import lombok.Data;

import java.util.concurrent.Delayed;
import java.util.concurrent.TimeUnit;

/**
 * @Description: 实现Delayed接口，重写getDelay（）和compareTo（）方法
 */
@Data
public class MyDelayQueue implements Delayed {

    private long time;
    private String desc;
    

    public MyDelayQueue(long time, String desc) {
        this.time = time * 1000 + System.currentTimeMillis();
        this.desc = desc;
    }

    //判断是否过期
    @Override
    public long getDelay(TimeUnit unit) {
        return time - System.currentTimeMillis();
    }

   //任务排序
    @Override
    public int compareTo(Delayed o) {
        MyDelayQueue delayTask = (MyDelayQueue) o;
        return time - delayTask.getTime() <= 0 ? -1 : 1;
    }
}
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测试

import com.alibaba.fastjson.JSONObject;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Objects;
import java.util.concurrent.DelayQueue;

/**
 * @Description:测试上面实现的延迟队列
 */
public class TestMyDelayQueue {
    public static void main(String[] args) throws InterruptedException {
        DelayQueue<MyDelayQueue> queue = new DelayQueue<>();
        queue.put(new MyDelayQueue(10, "10s后到期"));
        queue.put(new MyDelayQueue(30, "30s后到期"));
        queue.put(new MyDelayQueue(20, "20s后到期"));
        System.out.println("任务开始执行时间：" + new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").format(new Date()));
        while (queue.size() > 0) {
            MyDelayQueue delayTask = queue.take();
            if (Objects.nonNull(delayTask)) {
                System.out.println("过期任务：" + delayTask.getDesc() + "过期时间：" + new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").format(new Date(delayTask.getTime())));
            }
        }
    }
}
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控制台打印

任务开始执行时间：2022-11-10 01:06:47
过期任务：10s后到期过期时间：2022-11-10 01:06:57
过期任务：20s后到期过期时间：2022-11-10 01:07:07
过期任务：30s后到期过期时间：2022-11-10 01:07:17

Process finished with exit code 0
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