Redis使用Zset实现延时队列

最新推荐文章于 2024-10-31 17:34:22 发布

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最新推荐文章于 2024-10-31 17:34:22 发布

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分类专栏： Redis 文章标签： redis java

本文链接：https://blog.youkuaiyun.com/qq_26412535/article/details/119937253

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该博客展示了如何使用 Redis 的 Zset 结构实现延迟队列。生产者生成10个订单并设置不同延迟时间，消费者通过两种方式（轮询和查询条件）从 Redis 中取出并消费待执行的任务。示例代码包括了连接配置、订单生产及消费的详细步骤。

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package com.frame.cache.util;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.Iterator;
import java.util.Random;
import java.util.Set;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig;

import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.Tuple;

/**
 * @program: RedisZsetTest
 * @description: redis实现延时队列
 **/
public class RedisZsetTest {

    private static final String ADDR = "120.19.107.165";
    private static final int PORT = 6379;
    private static GenericObjectPoolConfig jedisPoolConfig = new GenericObjectPoolConfig();
    private static JedisPool jedisPool = new JedisPool(jedisPoolConfig,ADDR, PORT,500,"hradmin20180330");
    private static CountDownLatch cdl = new CountDownLatch(10);

    public static Jedis getJedis() {
        return jedisPool.getResource();
    }

    /**
     * 生产者,生成10个订单
     * @throws ParseException 
     */
    public void productionDelayMessage() throws Exception {
    	Jedis jedis = RedisZsetTest.getJedis();
        for (int i = 0; i < 10; i++) {
            Calendar instance = Calendar.getInstance();
            // 10秒后执行
            Random random = new Random();
            int nextInt = random.nextInt(10) + 10;
            instance.add(Calendar.SECOND, nextInt);
            Long score = (instance.getTimeInMillis()) / 1000;
           
            int orderId = random.nextInt(100) + 10;
            
            jedis.zadd("orderId", score, StringUtils.join("000000000", orderId));
            System.out.println("生产订单: " + StringUtils.join("000000000", orderId) + " 当前时间：" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()));
            System.out.println(nextInt + "秒后执行, 分数:"+score+",执行时间:" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(instance.getTime()));
            System.out.println();
        }
        jedis.close();
    }

    //消费者，取订单, 方式1, 轮询取
    public static void consumerDelayMessage1() {
        Jedis jedis = RedisZsetTest.getJedis();
        while (true) {
        	 Calendar instance = Calendar.getInstance();
        	 long nowTime = instance.getTimeInMillis() / 1000;
        	
            Set<Tuple> order = jedis.zrangeWithScores("orderId", 0, 0);
            if (order == null || order.isEmpty()) {
                System.out.println("当前没有等待的任务");
                try {
                    TimeUnit.MICROSECONDS.sleep(500);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                continue;
            }
            Tuple tuple = (Tuple) order.toArray()[0];//取出分值最小的那个
            double score = tuple.getScore();
            String element = tuple.getElement();
            
            System.out.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + ":redis消费了一个任务：消费的订单OrderId为" + element);

            if (nowTime >= score) {
            	Long orderId = jedis.zrem("orderId", element);
                if (orderId > 0) {
                    System.err.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + ":redis消费了一个任务：消费的订单OrderId为" + element);
                }
            }
        }
    }
    
    //消费者，取订单, 方式2, 查对应条件的
    public static void consumerDelayMessage2() {
    	while (true) {
    		Jedis jedis = RedisZsetTest.getJedis();
    		Calendar instance = Calendar.getInstance();
			Long nowTime = instance.getTimeInMillis() / 1000;
			Set<String> zrangeByScore = jedis.zrangeByScore("orderId", "0", nowTime.toString());//小于当前时间得值
			
			if(zrangeByScore.size()==0){
				try {
                    TimeUnit.MICROSECONDS.sleep(1000);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
				jedis.close();
                continue;
			}
			
			Iterator<String> iterator = zrangeByScore.iterator();
			while (iterator.hasNext()) {
				String next = iterator.next();
				Long result = jedis.zrem("orderId", next);
				if (result != null && result > 0) {
					System.err.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date())
							+ ":redis消费了一个任务：消费的订单OrderId为" + next);
				}
			}
			jedis.close();
    	}
    }

    static class DelayMessage implements Runnable{
        @Override
        public void run() {
            try {
                cdl.await();
                //consumerDelayMessage1();//方式1
                consumerDelayMessage2();//方式2
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }
    
    public static void main(String[] args) throws Exception {
        RedisZsetTest appTest = new RedisZsetTest();
        appTest.productionDelayMessage();
        for (int i = 0; i < 10; i++) {
            new Thread(new DelayMessage()).start();
            cdl.countDown();
        }
    }
}