Redis集群下过期key监听的实现代码

1.　前言

在使用redis集群时，发现过期key始终监听不到。网上也没有现成的解决方案。于是想，既然不能监听集群，那我可以建立多个redis连接，分别对每个redis的key过期进行监听。以上做法可能不尽人意，目前也没找到好的解决方案，如果有好的想法，请留言告知哦！不多说，直接贴我自己的代码！

2.　代码实现

关于Redis集群配置代码此处不贴，直接贴配置监听类代码！

redis.host1: 10.113.56.68
redis.port1: 7030
redis.host2: 10.113.56.68
redis.port2: 7031
redis.host3: 10.113.56.68
redis.port3: 7032
redis.host4: 10.113.56.68
redis.port4: 7033
redis.host5: 10.113.56.68
redis.port5: 7034
redis.host6: 10.113.56.68
redis.port6: 7035

import org.springframework.beans.factory.annotation.Value;
import org.springframework.cache.CacheManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.RedisClusterConfiguration;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.listener.RedisMessageListenerContainer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPoolConfig;

import java.util.Arrays;

/**
 * @Author xiabing5
 * @Create 2019/8/6 14:46
 * @Desc  监听redis中Key过期事件
 **/
@Configuration
public class RedisListenerConfig {

  @Value("${redis.host1}")
  private String host1;

  @Value("${redis.host2}")
  private String host2;

  @Value("${redis.host3}")
  private String host3;

  @Value("${redis.host4}")
  private String host4;

  @Value("${redis.host5}")
  private String host5;

  @Value("${redis.host6}")
  private String host6;

  @Value("${redis.port1}")
  private int port1;

  @Value("${redis.port2}")
  private int port2;

  @Value("${redis.port3}")
  private int port3;

  @Value("${redis.port4}")
  private int port4;

  @Value("${redis.port5}")
  private int port5;

  @Value("${redis.port6}")
  private int port6;

  @Bean
  JedisPoolConfig jedisPoolConfig(){
    JedisPoolConfig jedisPoolConfig = new JedisPoolConfig();
    jedisPoolConfig.setMaxIdle(100);
    jedisPoolConfig.setMaxWaitMillis(1000);
    return jedisPoolConfig;
  }

  // redis-cluster不支持key过期监听，建立多个连接，对每个redis节点进行监听
  @Bean
  RedisMessageListenerContainer redisContainer1() {
    final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
    JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
    jedisConnectionFactory.setHostName(host1);
    jedisConnectionFactory.setPort(port1);
    jedisConnectionFactory.setPoolConfig(jedisPoolConfig());
    jedisConnectionFactory.afterPropertiesSet();
    container.setConnectionFactory(jedisConnectionFactory);
    return container;
  }

  @Bean
  RedisMessageListenerContainer redisContainer2() {
    final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
    JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
    jedisConnectionFactory.setHostName(host2);
    jedisConnectionFactory.setPort(port2);
    jedisConnectionFactory.setPoolConfig(jedisPoolConfig());
    jedisConnectionFactory.afterPropertiesSet();
    container.setConnectionFactory(jedisConnectionFactory);
    return container;
  }

  @Bean
  RedisMessageListenerContainer redisContainer3() {
    final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
    JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
    jedisConnectionFactory.setHostName(host3);
    jedisConnectionFactory.setPort(port3);
    jedisConnectionFactory.setPoolConfig(jedisPoolConfig());
    jedisConnectionFactory.afterPropertiesSet();
    container.setConnectionFactory(jedisConnectionFactory);
    return container;
  }

  @Bean
  RedisMessageListenerContainer redisContainer4() {
    final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
    JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
    jedisConnectionFactory.setHostName(host4);
    jedisConnectionFactory.setPort(port4);
    jedisConnectionFactory.setPoolConfig(jedisPoolConfig());
    jedisConnectionFactory.afterPropertiesSet();
    container.setConnectionFactory(jedisConnectionFactory);
    return container;
  }

  @Bean
  RedisMessageListenerContainer redisContainer5() {
    final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
    JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
    jedisConnectionFactory.setHostName(host5);
    jedisConnectionFactory.setPort(port5);
    jedisConnectionFactory.setPoolConfig(jedisPoolConfig());
    jedisConnectionFactory.afterPropertiesSet();
    container.setConnectionFactory(jedisConnectionFactory);
    return container;
  }

  @Bean
  RedisMessageListenerContainer redisContainer6() {
    final RedisMessageListenerContainer container = new RedisMessageListenerContainer();
    JedisConnectionFactory jedisConnectionFactory = new JedisConnectionFactory();
    jedisConnectionFactory.setHostName(host6);
    jedisConnectionFactory.setPort(port6);
    jedisConnectionFactory.setPoolConfig(jedisPoolConfig());
    jedisConnectionFactory.afterPropertiesSet();
    container.setConnectionFactory(jedisConnectionFactory);
    return container;
  }

  @Bean
  RedisKeyExpirationListener redisKeyExpirationListener1() {
    return new RedisKeyExpirationListener(redisContainer1());
  }

  @Bean
  RedisKeyExpirationListener redisKeyExpirationListener2() {
    return new RedisKeyExpirationListener(redisContainer2());
  }

  @Bean
  RedisKeyExpirationListener redisKeyExpirationListener3() {
    return new RedisKeyExpirationListener(redisContainer3());
  }

  @Bean
  RedisKeyExpirationListener redisKeyExpirationListener4() {
    return new RedisKeyExpirationListener(redisContainer4());
  }

  @Bean
  RedisKeyExpirationListener redisKeyExpirationListener5() {
    return new RedisKeyExpirationListener(redisContainer5());
  }

  @Bean
  RedisKeyExpirationListener redisKeyExpirationListener6() {
    return new RedisKeyExpirationListener(redisContainer6());
  }

}

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.connection.Message;
import org.springframework.data.redis.listener.KeyExpirationEventMessageListener;
import org.springframework.data.redis.listener.RedisMessageListenerContainer;
import java.util.Date;

/**
 * @Author xiabing5
 * @Create 2019/9/4 9:47
 * @Desc  redis过期监听
 **/
public class RedisKeyExpirationListener extends KeyExpirationEventMessageListener {
  @Autowired
  RedisUtil redisUtil;
  @Autowired
  LoginUserStatisticsMapper loginUserStatisticsMapper;
  public RedisKeyExpirationListener(RedisMessageListenerContainer listenerContainer) {
    super(listenerContainer);
  }
  @Override
  public void onMessage(Message message, byte[] pattern) {
    // 用户做自己的业务处理即可,message.toString()可以获取失效的key
    String mesg = message.toString();
  }
}

3.　Redis防止过期key重复监听

对于项目集群情况下，部署多个服务后，容易出现redis过期被多个服务同时监听到，从而执行相同的业务逻辑，这不是我们期望的。单机部署下方法的同步可以采用synchronize关键字。但集群下，就得采用分布式锁。在需要加锁的地方，只要加锁和解锁即可。此处正好写到Redis，那就贴一个自己用的redis分布式锁。

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import redis.clients.jedis.Jedis;
import java.util.Collections;
import java.util.UUID;
/**
 * @Author xiabing5
 * @Create 2019/9/6 15:54
 * @Desc  redis分布式锁
 **/
@Component
public class RedisLock {
  @Autowired
  Jedis jedis;
  private static final String SET_IF_NOT_EXIST = "NX"; // NX表示如果不存在key就设置value
  private static final String SET_WITH_EXPIRE_TIME = "PX"; // PX表示毫秒
  // 加锁
  public String tryLock(String key,Long acquireTimeout) {
    // 生成随机value
    String identifierValue = UUID.randomUUID().toString();
    // 设置超时时间
    Long endTime = System.currentTimeMillis() + acquireTimeout;
    // 循环获取锁
    while (System.currentTimeMillis() < endTime) {
      String result = jedis.set(key,identifierValue, SET_IF_NOT_EXIST, SET_WITH_EXPIRE_TIME, acquireTimeout);
      if("OK".equals(result)) {
        return identifierValue;
      }
    }
    return null;
  }
  // 解锁
//  public void delLock(String key,String identifierValue) {
//    // 判断是否是同一把锁
//    try{
//      if(jedis.get(key).equals(identifierValue)){
//        // 此处操作非原子性，容易造成释放非自己的锁
//        jedis.del(key);
//      }
//    }catch(Exception e) {
//      e.printStackTrace();
//    }
//  }
  // 使用Lua代码解锁
  public void delLock(String key,String identifierValue) {
    try{
      String script = "if redis.call('get', KEYS[1]) == ARGV[1] then return redis.call('del', KEYS[1]) else return 0 end";
      Long result = (Long) jedis.eval(script, Collections.singletonList(key), Collections.singletonList(identifierValue));
      if (1 == result) {
        System.out.println(result+"释放锁成功");
      } if (0 == result) {
        System.out.println(result+"释放锁失败");
      }
    }catch (Exception e) {
      e.printStackTrace();
    }
  }
}

4.　总结

自己实现的一个小demo,废话比较少。小白自己写的配置类，理解有问题请留言！自己实现的方案感觉不妥，只是基本完成需求，还得继续研究。

以上所述是小编给大家介绍的Redis集群下过期key监听的实现代码,希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对我们网站的支持！
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