java中DelayQueue实例用法详解

public class DelayObject implements Delayed {
  private String data;
  private long startTime;
  public DelayObject(String data, long delayInMilliseconds) {
    this.data = data;
    this.startTime = System.currentTimeMillis() + delayInMilliseconds;
}

package org.dromara.hmily.demo.springcloud.account.service;
 
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}\n",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 + '\'' +
        '}';
  }
}

begin time:2019-05-31T11:58:24.445
name:{item1}, time:{2019-05-31T11:58:29.262}
name:{item2}, time:{2019-05-31T11:58:34.262}
name:{item3}, time:{2019-05-31T11:58:39.262}