Redis之监听失效Key

港控/mmm° 2022-04-18 06:18 308阅读 0赞

修改Redis配置

1. 事件通过 Redis 的订阅与发布功能（pub/sub）来进行分发,故需要订阅 \_\_keyevent@0\_\_:expired 通道0表示db0，根据自己的dbindex选择合适的数字（客户端执行redis 命令。psubscribe \_\_keyevent@\*\_\_:expired ）

2. 修改 redis.conf 文件

修改 notify-keyspace-events Ex

3. 重启redis , 即可测试失效事件的触发, 监听获取的值为 key

redis配置好后，现在来准备java测试代码

SpringConfig文件，配置listenerContainer，redisKeyExpirationListener两个bean

package com.yj.config;
    
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.ComponentScan;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.data.redis.connection.RedisConnectionFactory;
    import org.springframework.data.redis.listener.KeyExpirationEventMessageListener;
    import org.springframework.data.redis.listener.RedisMessageListenerContainer;
    import com.yj.listener.RedisKeyExpirationListener;
    
    @Configuration
    @ComponentScan("com.yj")
    public class SpringConfig {
    	@Bean
    	RedisMessageListenerContainer listenerContainer(RedisConnectionFactory connectionFactory) {
    		RedisMessageListenerContainer listenerContainer = new RedisMessageListenerContainer();
    		listenerContainer.setConnectionFactory(connectionFactory);
    		return listenerContainer;
    	}
    
    	@Bean
    	KeyExpirationEventMessageListener redisKeyExpirationListener(RedisMessageListenerContainer listenerContainer) {
    		return new RedisKeyExpirationListener(listenerContainer);
    	}
    }

RedisKeyExpirationListener文继承KeyExpirationEventMessageListener，重写onMessage回调方法

package com.yj.listener;
    
    import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springframework.data.redis.connection.Message;
    import org.springframework.data.redis.listener.KeyExpirationEventMessageListener;
    import org.springframework.data.redis.listener.RedisMessageListenerContainer;
    
    public class RedisKeyExpirationListener extends KeyExpirationEventMessageListener {
    	private static final Logger logger = LoggerFactory.getLogger(RedisKeyExpirationListener.class);
    
    	public RedisKeyExpirationListener(RedisMessageListenerContainer listenerContainer) {
    		super(listenerContainer);
    	}
    
    	@Override
    	public void onMessage(Message message, byte[] pattern) {
    		String redisKey = message.toString();
    		logger.info("即将要失效的Key:" + redisKey);
    	}
    }

我们往redis中插入一条expire为10秒的数据，则当key失效时，会触发监听，打印出

2018-11-09 15:04:08.209  INFO 10360 --- [enerContainer-2] c.y.listener.RedisKeyExpirationListener  : 即将要失效的Key:test