This is the 5 minute tour to get started with Spring AMQP.
Prerequisites: install and run the RabbitMQ broker (http://www.rabbitmq.com/download.html). Then grab the spring-rabbit JAR and all its dependencies - the easiest way to do that is to declare a dependency in your build tool, e.g. for Maven:
<dependency> <groupId>org.springframework.amqp</groupId> <artifactId>spring-rabbit</artifactId> <version>1.3.9.RELEASE</version> </dependency>
Using plain, imperative Java to send and receive a message:
ConnectionFactory connectionFactory = new CachingConnectionFactory(); AmqpAdmin admin = new RabbitAdmin(connectionFactory); admin.declareQueue(new Queue("myqueue")); AmqpTemplate template = new RabbitTemplate(connectionFactory); template.convertAndSend("myqueue", "foo"); String foo = (String) template.receiveAndConvert("myqueue");
Note that there is a ConnectionFactory
in
the native Java Rabbit client as well. We are using the Spring
abstraction in the code above. We are relying on the default exchange in
the broker (since none is specified in the send), and the default
binding of all queues to the default exchange by their name (hence we
can use the queue name as a routing key in the send). Those behaviours
are defined in the AMQP specification.
The same example as above, but externalizing the resource configuration to XML:
ApplicationContext context = new GenericXmlApplicationContext("classpath:/rabbit-context.xml"); AmqpTemplate template = context.getBean(AmqpTemplate.class); template.convertAndSend("myqueue", "foo"); String foo = (String) template.receiveAndConvert("myqueue");
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:rabbit="http://www.springframework.org/schema/rabbit" xsi:schemaLocation="http://www.springframework.org/schema/rabbit http://www.springframework.org/schema/rabbit/spring-rabbit.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <rabbit:connection-factory id="connectionFactory"/> <rabbit:template id="amqpTemplate" connection-factory="connectionFactory"/> <rabbit:admin connection-factory="connectionFactory"/> <rabbit:queue name="myqueue"/> </beans>
The <rabbit:admin/>
declaration by default
automatically looks for beans of type Queue
,
Exchange
and Binding
and
declares them to the broker on behalf of the user, hence there is no
need to use that bean explicitly in the simple Java driver. There are
plenty of options to configure the properties of the components in the
XML schema - you can use auto-complete features of your XML editor to
explore them and look at their documentation.
The same example again with the external configuration in Java:
ApplicationContext context = new AnnotationConfigApplicationContext(RabbitConfiguration.class); AmqpTemplate template = context.getBean(AmqpTemplate.class); template.convertAndSend("myqueue", "foo"); String foo = (String) template.receiveAndConvert("myqueue");
@Configuration public class RabbitConfiguration { @Bean public ConnectionFactory connectionFactory() { CachingConnectionFactory connectionFactory = new CachingConnectionFactory("localhost"); return connectionFactory; } @Bean public AmqpAdmin amqpAdmin() { return new RabbitAdmin(connectionFactory()); } @Bean public RabbitTemplate rabbitTemplate() { return new RabbitTemplate(connectionFactory()); } @Bean public Queue myQueue() { return new Queue("myqueue"); } }