Redis publish subscribe to node.js

Disclaimer: This is no way a comparison between RabbitMQ and Redis. RabbitMQ is a great product and we use it in our startup as a queuing system. I just wanted to try out redis in my pet project so I did it.

I am intrigued by the hype around node.js so am planning of writing a node.js to push real time events from server and do push notifications in browser from server.

Now mostly I saw that people use a myriad of technologies from websocket, nginx, nodejs, redis/rabbitmq and in backend produce the message from Java or any other app.  Basically node.js is only used for long polling and decoupled from the main app using a message queue as a broker. So my first goal was to push message from Java to message queue and I have already used RabbitMQ in past so I thought let me this time try redis and boy it is much much easy then RabbitMQ (however at this moment I trust rabbitmq more than redis for production as I have much more experience scaling rabbitmq as a queuing system,  I just wanted to try out a different queuing system).


To connect to redis from java there are multiple implementations like JRedis and Jedis, in past in my startup we had used JRedis and then switched to Jedis but I am not happy with that code as we did all code ourselves so thought to check if spring has something because I am a big time fan of spring-jdbc and luckily I found spring has a similar abstraction to hide all this details using its spring-data-redis templates.  I used spring-data-redis-1.1.0.RELEASE and jedis-2.1.0.jar and I ran into issues with spring-3.X so I upgraded to spring-tx-4.0.1.RELEASE.jar

all I needed to do was to add this in spring config

 <bean id="jedisConnectionFactory" class="org.springframework.data.redis.connection.jedis.JedisConnectionFactory"
        p:host-name="127.0.0.1" p:port="6379"/>
    
      <bean id="stringRedisTemplate" class="org.springframework.data.redis.core.StringRedisTemplate"
    p:connection-factory-ref="jedisConnectionFactory"/>
 
      <bean id="messagePublisher" class="com.kp.common.server.pubsub.MessagePublisher">
        <property name="stringRedisTemplate" ref="stringRedisTemplate" />
      </bean>

and then

public class MessagePublisher {
    private static final AppLogger logger = AppLogger.getLogger(MessagePublisher.class);
    private StringRedisTemplate stringRedisTemplate;

    public StringRedisTemplate getStringRedisTemplate() {
        return stringRedisTemplate;
    }

    public void setStringRedisTemplate(StringRedisTemplate stringRedisTemplate) {
        this.stringRedisTemplate = stringRedisTemplate;
    }

    public void publishMessage(String channel, String message) {
        logger.debug("Publishing {} to channel {}", message, channel);
        stringRedisTemplate.convertAndSend(channel, message);
    }

    public void publishJsonMessage(String channel, Object msgObject) {
        publishMessage(channel, JsonUtil.generateJSON(msgObject));
    }
}

Now can you beat this.  2 lines of code to publish a message to message queue.  Totally impressed and icing on cake is that if you have to switch the library from jedis to Jredis then its just a config change and no code change is required and spring is handing all connection open/close.