Introducing Spring Framework

Chapter 16
Messaging with Your Spring
Application
In Chapter 11, you integrated your Spring application with JMS and RabbitMQ servers. In this chapter, I’ll talk more
about RabbitMQ and the Spring AMQP (Advance Message Queue Protocol) module. Imagine for a moment that you
are going to receive a lot of new documents and at some point you will want to classify them by extension.
An easy way to do this classification by extension is to create a RabbitMQ queue. Once the message arrives to the
consumer, they get the Type and the Extension, and then based on these two properties, do some processing. Well,
that sounds like the right way to do it. But you are going to want to process as many documents as you can, and if you
do, this solution might become overwhelming.
So how are you going to solve this problem? The good news is that you can take advantage of a nice set of features
from RabbitMQ that differs from other brokers. RabbitMQ provides a routing mechanism for free. I’ll explain the
RabbitMQ’s routing features in the following paragraphs, but first you need to do some coding.
Using RabbitMQ
Let’s start by creating the producer that will emulate all the documents that will be sent to you. See Listing 16-1 for the
RabbitMQProducer class.
Listing 16-1. RabbitMQProducer.java
package com.apress.isf.spring.amqp;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import com.apress.isf.java.model.Document;
@Component("rabbitmqProducer")
public class RabbitMQProducer {
private static final String EXCHANGE = "mydocuments";
@Autowired
private RabbitTemplate rabbitTemplate;
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