redis 主键过期发布与订阅机制

你的名字 2022-11-21 04:23 126阅读 0赞

说明：本问为redis信息失效发布demo:

使用场景：如订单定时未支付，可将订单id存入redis设置过期时间，

结合mq做订单失效，库存回补功能；

1.开启过期订阅功能。

import com.example.demo.listener.KeyExpiredListener;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.data.redis.connection.RedisConnectionFactory;
    import org.springframework.data.redis.listener.PatternTopic;
    import org.springframework.data.redis.listener.RedisMessageListenerContainer;
    
    /**
     * redis配置文件开启：
     *notify-keyspace-events Ex
     * redis过期消息订阅功能
     */
    @Configuration
    public class PubsubConfiguration {
        @Autowired
        private  RedisConnectionFactory redisConnectionFactory;
        /**
         * 设置订阅事件
         * @return
         */
        @Bean
        public PatternTopic patternTopic(){
            return new PatternTopic("__keyevent@*__:expired");//订阅所有库
        }
        @Bean
        RedisMessageListenerContainer container() {
            RedisMessageListenerContainer container = new RedisMessageListenerContainer();
            container.setConnectionFactory(redisConnectionFactory);
            return container;
        }
        @Bean
        public KeyExpiredListener keyExpiredListener(){
            return new KeyExpiredListener(container());
        }
    
    }

2.收集过期信息，做相应业务处理；

import lombok.extern.slf4j.Slf4j;
    import org.springframework.data.redis.connection.Message;
    import org.springframework.data.redis.listener.KeyExpirationEventMessageListener;
    import org.springframework.data.redis.listener.RedisMessageListenerContainer;
    import org.springframework.lang.Nullable;
    
    import java.nio.charset.StandardCharsets;
    
    /**
     * redis失效消息推送
     */
    @Slf4j
    public class KeyExpiredListener extends KeyExpirationEventMessageListener {
        public KeyExpiredListener(RedisMessageListenerContainer listenerContainer) {
            super(listenerContainer);
    
        }
    
        /**
         * redis消息失效的监听
         *
         * @param message
         * @param pattern
         */
        @Override
        public void onMessage(Message message, @Nullable byte[] pattern) {
            String channel = new String(message.getChannel(), StandardCharsets.UTF_8);
            String key = new String(message.getBody(), StandardCharsets.UTF_8);
            String patterString = new String(message.getBody(), StandardCharsets.UTF_8);
            log.info("key 失效：channel：{}；key：{}；patterString：{}", channel, key, patterString);
            //以下可做业务处理（结合mq处理过期消息）
    
        }
    }