使用redis实现延迟通知功能(Redis过期键通知)

Redis 过期监听场景

业务中有类似等待一定时间之后执行某种行为的需求 , 比如 30 分钟之后关闭订单 . 网上有很多使用 Redis 过期监听的 Demo

redis配置

把notify-keyspace-events Ex 这一行的注释打开

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项目demo工程

项目结构如下图

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maven依赖

<?xml version="1.0" encoding="UTF-8"?>

    
        kim-redis
        com.kim
        1.0.0
    
    4.0.0

    kim-redis-expiration-notice

    
        
            org.springframework.boot
            spring-boot-starter-web
        
        
            org.springframework.boot
            spring-boot-starter-redis
        

        
            org.projectlombok
            lombok
        
        
            org.apache.commons
            commons-pool2

配置文件

server:
  port: 20103

spring:
  redis:
    #数据库索引
    database: 0
    host: 127.0.0.1
    port: 6379
    password: 123456
    lettuce:
      pool:
        #最大连接数
        max-active: 8
        #最大阻塞等待时间(负数表示没限制)
        max-wait: -1
        #最大空闲
        max-idle: 8
        #最小空闲
        min-idle: 0
    #连接超时时间
    timeout: 10000

启动类

/**
 * @Project: kim-redis
 * @PackageName: com.kim.redis.expiration.notice
 * @FileName: NoticeApplication.java
 * @Description: The NoticeApplication is...
 * @Author: kimwu
 * @Time: 2020-12-19 14:01:56
 */
@SpringBootApplication
public class NoticeApplication {

    public static void main(String[] args) {
        SpringApplication.run(NoticeApplication.class, args);
    }

}

配置类

@Configuration
public class RedisTimeoutConfiguration {

    @Autowired
    private RedisConnectionFactory redisConnectionFactory;

    @Bean
    public RedisMessageListenerContainer redisMessageListenerContainer() {
        RedisMessageListenerContainer redisMessageListenerContainer = new RedisMessageListenerContainer();
        redisMessageListenerContainer.setConnectionFactory(redisConnectionFactory);
        return redisMessageListenerContainer;
    }

    @Bean
    public KeyExpiredListener keyExpiredListener() {
        return new KeyExpiredListener(this.redisMessageListenerContainer());
    }
}

监听类

@Slf4j
public class KeyExpiredListener extends KeyExpirationEventMessageListener {


    public KeyExpiredListener(RedisMessageListenerContainer listenerContainer) {
        super(listenerContainer);
    }

    @Override
    public void onMessage(Message message, byte[] pattern) {
        String channel = new String(message.getChannel(), StandardCharsets.UTF_8);
        //过期的key
        String key = new String(message.getBody(), StandardCharsets.UTF_8);
        log.info("redis key 过期：pattern={},channel={},key={}", new String(pattern), channel, key);
    }
}