redis 超时失效key 的监听触发

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

 

2. 修改 redis.conf 文件 

修改 notify-keyspace-events Ex 

# K    键空间通知,以__keyspace@__为前缀
# E    键事件通知,以__keysevent@__为前缀
# g    del , expipre , rename 等类型无关的通用命令的通知, ...
# $    String命令
# l    List命令
# s    Set命令
# h    Hash命令
# z    有序集合命令
# x    过期事件(每次key过期时生成)
# e    驱逐事件(当key在内存满了被清除时生成)
# A    g$lshzxe的别名,因此”AKE”意味着所有的事件

3. 重启redis , 即可测试失效事件的触发, 监听获取的值为 key

 

1.  首先需要一个消息监听器类

package com.sogou.baike.testimport.testSubscribe;  
  
import redis.clients.jedis.JedisPubSub;  
  
/**  
 * Created by denglinjie on 2016/6/29.  
 */  
public class RedisMsgPubSubListener extends JedisPubSub {  
    @Override  
    public void unsubscribe() {  
        super.unsubscribe();  
    }  
  
    @Override  
    public void unsubscribe(String... channels) {  
        super.unsubscribe(channels);  
    }  
  
    @Override  
    public void subscribe(String... channels) {  
        super.subscribe(channels);  
    }  
  
    @Override  
    public void psubscribe(String... patterns) {  
        super.psubscribe(patterns);  
    }  
  
    @Override  
    public void punsubscribe() {  
        super.punsubscribe();  
    }  
  
    @Override  
    public void punsubscribe(String... patterns) {  
        super.punsubscribe(patterns);  
    }  
  
    @Override  
    public void onMessage(String channel, String message) {  
        System.out.println("channel:" + channel + "receives message :" + message);  
        this.unsubscribe();  
    }  
  
    @Override  
    public void onPMessage(String pattern, String channel, String message) {  
  
    }  
  
    @Override  
    public void onSubscribe(String channel, int subscribedChannels) {  
        System.out.println("channel:" + channel + "is been subscribed:" + subscribedChannels);  
    }  
  
    @Override  
    public void onPUnsubscribe(String pattern, int subscribedChannels) {  
  
    }  
  
    @Override  
    public void onPSubscribe(String pattern, int subscribedChannels) {  
  
    }  
  
    @Override  
    public void onUnsubscribe(String channel, int subscribedChannels) {  
        System.out.println("channel:" + channel + "is been unsubscribed:" + subscribedChannels);  
    }  
}  

该类需要继承JedisPubSub ,并实现其抽象方法,通过方法的名称很清楚的看出来,这个监听器是用来订阅一个频道,在订阅该频道,取消订阅,收到消息等状态会对应调用相关的方法

 

 

2.  订阅测试

public class TestSubscribe {  
    @Test  
    public void testSubscribe() throws Exception{  
        Jedis jedis = new Jedis("localhost");  
        RedisMsgPubSubListener listener = new RedisMsgPubSubListener();  
        jedis.subscribe(listener, "__keyevent@0__:expired");  
        //other code  
    }  
}  

该类实现对频道redisChatTest的订阅监听,频道的订阅,取消订阅,收到消息都会调用listener对象的对应方法

 

注意:subscribe是一个阻塞的方法,在取消订阅该频道前,会一直阻塞在这,只有当取消了订阅才会执行下面的other code,参考上面代码,我在onMessage里面收到消息后,调用了this.unsubscribe(); 来取消订阅,这样才会执行后面的other code

 

3.  发布消息测试

Public class TestPublish {  
    @Test  
    public void testPublish() throws Exception{  
        Jedis jedis = new Jedis("localhost");  
        jedis.publish("redisChatTest", "我是天才");  
        Thread.sleep(5000);  
        jedis.publish("redisChatTest", "我牛逼");  
        Thread.sleep(5000);  
        jedis.publish("redisChatTest", "哈哈");  
    }  
}  

这个类向频道redisChatTest发布消息,第二步因为订阅了该频道,所以会收到该消息。

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