redis的pub和sub

redis的pub和sub功能实现

顾名思义，可以分成pub和sub两个部分，先来说说sub

要实现redis的sub，首先必须新建一个实现了abstract   类  JedisPubSub的功能类

public class RedisTopicListener extends JedisPubSub {
    private static Logger logger = LoggerFactory.getLogger(RedisTopicListener.class);
    private RedisTopicProcessor redisMsgProcessor;
    
    @Override
    public void onMessage(String channel, String message) {
        logger.trace("channel:{}, msg:{}", channel, message);
        redisMsgProcessor.process(message);         //这里调用了另一个类的process方法来实现收到channel的message消息时所做的操作
    }

    @Override
    public void onPMessage(String pattern, String channel, String message) {
        logger.trace("pattern:{}, channel:{}, msg:{}", new Object[]{pattern, channel, message});
    }


    @Override
    public void onSubscribe(String channel, int subscribedChannels) {
        logger.info("RedisTopicListener onSubscribe, channel:{}, subscribedChannels:{}",
                new Object[]{channel, subscribedChannels});
    }

    @Override
    public void onUnsubscribe(String channel, int subscribedChannels) {
        logger.info("RedisTopicListener onUnsubscribe, channel:{}, subscribedChannels:{}",
                new Object[]{channel, subscribedChannels});
    }

    @Override
    public void onPUnsubscribe(String pattern, int subscribedChannels) {
        logger.info("RedisTopicListener onPUnsubscribe, pattern:{}, subscribedChannels:{}",
                new Object[]{pattern, subscribedChannels});
    }

    @Override
    public void onPSubscribe(String pattern, int subscribedChannels) {
        logger.info("RedisTopicListener onPSubscribe, pattern:{}, subscribedChannels:{}",
                new Object[]{pattern, subscribedChannels});
    }

    public RedisTopicProcessor getRedisMsgProcessor() {
        return redisMsgProcessor;
    }

    public void setRedisMsgProcessor(RedisTopicProcessor redisMsgProcessor) {
        this.redisMsgProcessor = redisMsgProcessor;
    }
}

在实现了该JedisPubSub虚拟类的时候，需要在另外的subscribe方法中调用该jedisPubSub类的实例，具体代码如下：

public   Class  classA{

    private JedisPool jedisPool;
    
    private JedisPubSub jedisPubSub;
    
    private String lockFileName;
    
    private String topicName;

    public static void start(){
        logger.info("start to transmit message from topic:{}", topicName);     
        Jedis jedis = jedisPool.getResource();
        
        logger.info("subscribe topic:{}", topicName);
        jedis.subscribe(jedisPubSub, topicName);   调用subscribe方法，从topic中读取数据

注意这里的jedisPubSub所注入的 是RedisTopicListener的实例。

       }

}

public class classB{

     public static void main(String[] args){

         ClassA clsa = new ClassA();

          clsa.start();                             //在启动线程时，自动调用start方法

         System.exit(0);

     }

}

//如下为pub 部分

public class ClassC {

      JedisPool jedisPool;    //注意这里注入的jedisPool一定要和sub端监听的jedisPool一样

       public void pub(){

              Jedis jedis = jedisPool.getResource();

               jedis.public("listen-Key", "1");

               jedis.public("listen-Key", "2");

               jedis.public("listen-Key", "3");

       }

}

public class ClassD{

      public static void main(String[] args){

            ClassC clsc = new ClassC();

            clsc.pub();

      }

}