How to configure consumers with spring xml-namespace

[sruch]

Hi all,

I am new to Spring AMQP playing arround with RabbitMQ. Just studied some examples from a talk of Rob (http://www.infoq.com/presentations/M...-with-RabbitMQ) in france this year (I guess) where he introduceces the stockprice example being consumed by different clients and languages. Being inspired by the example I wanted to implement a little webapplication where i can subscribe to news-channels and receive the news as far as a news producer creates a news for this channel. So I have a little mvc-controller where I can subscribe to three different news-channel. After subscribing to the channel the application changes to a screen with long polling and checks wheter ther is a news in the channel I just subscribed to. On the publisher side there is a litte controller where I can create a news and assign it to one or more channels. So far so good. With only one subscriber this works fine. But if a second subscriber subscribes to the same channel I get the problem that the messages are distributed round-robin between the subscriber. In the stockprice example Rob fixed this in changing the implementation of the consumer (subscriber) part. This was done on the low-level-api of RabbitMQ-Client. My question now is how can I configure Rabbit correctly to achieve the goal I described above? I've tried different things on the publisher-side with different exchange-types etc. Actually I think I can go with the topic-exchange-type where I have one topic-exchange "news.topic" and multiple bindings to different queues.

Here is my configuration:

	<rabbit:connection-factory id="connectionFactory" username="guest" password="guest" host="localhost"/>
	
	<rabbit:template id="news.publish.rabbitTemplate" exchange="news.topic" connection-factory="connectionFactory" message-converter="jsonMessageConverter"/>
	
	<rabbit:admin connection-factory="connectionFactory" />

 	<rabbit:topic-exchange name="news.topic">
		<rabbit:bindings>
			<rabbit:binding queue="news.sport" pattern="news.sport"/>
			<rabbit:binding queue="news.economy" pattern="news.economy"/>
			<rabbit:binding queue="news.international" pattern="news.international"/>
		</rabbit:bindings>
	</rabbit:topic-exchange>

	<rabbit:queue name="news.sport" />
	<rabbit:queue name="news.economy"/>
	<rabbit:queue name="news.international" />

I know there goes a lot under the hood in configuring with namespace... so maybe a just missed some configuration properties.
The consumer consumes the messages asynchronously just with this code:

...
	@Inject
	@Named("connectionFactory")
	private ConnectionFactory rabbitConnectionFactory;

	@Override
	public void subscribe(	String newsChannel,
							MessageListener listener)
	{
		SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
		container.setConnectionFactory(this.rabbitConnectionFactory);
		container.setQueueNames(newsChannel);
		container.setMessageListener(listener);
		container.setAcknowledgeMode(AcknowledgeMode.MANUAL);
		container.start();
	}
...

Can someone point me to the missing "magic"? :-)

Thanks and cheers,
Sandro

[sruch]

We just found the solution and wanted to share it... In this case the namespace-config (we think) does not work... but you can do it manually on your own (or with java-config)... the simple part was:

...
	@Inject
	@Named("connectionFactory")
	private ConnectionFactory rabbitConnectionFactory;

	@Inject
	private RabbitAdmin rabbitAdmin;

	private Map<Integer, SimpleMessageListenerContainer> containers = new HashMap<Integer, SimpleMessageListenerContainer>();

	@Override
	public void subscribe(	String newsChannel,
							MessageListener listener)
	{
		Queue q = new AnonymousQueue();
		rabbitAdmin.declareQueue(q);
		Binding binding = BindingBuilder.bind(q).to(new TopicExchange("amq.topic")).with(newsChannel);
		rabbitAdmin.declareBinding(binding);

		SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
		container.setConnectionFactory(rabbitConnectionFactory);
		container.setMessageListener(listener);
		container.setQueues(q);
		container.start();

		containers.put(listener.hashCode(), container);
	}
...

The key point here is to use the RabbitAdmin component to register the new queue on Rabbit...

Thats it... :-)