一. 开启Redis key过期提醒

• 方式一：修改配置文件

  redis.conf

  # 默认 notify-keyspace-events ""
  notify-keyspace-events Ex
  

• 方式二：命令行开启

  CONFIG SET notify-keyspace-events Ex
  CONFIG GET notify-keyspace-events
  

二. notify-keyspace-events

notify-keyspace-events 选项的默认值为空

notify-keyspace-events 的参数可以是以下字符的任意组合， 它指定了服务器该发送哪些类型的通知。

三. Coding

1. 初始化一个Spring Boot项目

2. pom.xml

   <dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-redis</artifactId></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency>
   </dependencies>
   

3. 定义配置类`RedisListenerConfig

   @Configuration
   public class RedisListenerConfig {@BeanRedisMessageListenerContainer container(RedisConnectionFactory connectionFactory) {RedisMessageListenerContainer container = new RedisMessageListenerContainer();container.setConnectionFactory(connectionFactory);return container;}}
   

4. 定义监听器 实现KeyExpirationEventMessageListener接口
   查看源码发现，该接口监听所有db的过期事件keyevent@*:expired"
   定义Status1ExpirationListener监听状态1到期

   @Slf4j
   @Component
   public class Status1ExpirationListener extends KeyExpirationEventMessageListener {public Status1ExpirationListener(RedisMessageListenerContainer listenerContainer) {super(listenerContainer);}@Autowiredprivate StringRedisTemplate stringRedisTemplate;@Overridepublic void onMessage(Message message, byte[] pattern) {// message.toString()可以获取失效的keyString expiredKey = message.toString();// 业务处理}}
   

   定义Status2ExpirationListener监听状态2到期

   @Slf4j
   @Component
   public class Status2ExpirationListener extends KeyExpirationEventMessageListener {public Status2ExpirationListener(RedisMessageListenerContainer listenerContainer) {super(listenerContainer);}@Overridepublic void onMessage(Message message, byte[] pattern) {// message.toString()可以获取失效的keyString expiredKey = message.toString();// 业务处理}}
   

四. 参考

Redis keyspace notifications