2. Introduction

While the default Spring Framework version dependency is 4.2.x, Spring AMQP is generally compatible with earlier versions of Spring Framework. Annotation-based listeners and the RabbitMessagingTemplate require Spring Framework 4.1 or higher, however.

Similarly, the default amqp-client version is 3.6.x but the framework is compatible with versions 3.4.0 and above. However, of course, features that rely on newer client versions will not be available. Note the this refers to the java client library; generally, it will work with older broker versions.

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() {
        return new CachingConnectionFactory("localhost");
    }

    @Bean
    public AmqpAdmin amqpAdmin() {
        return new RabbitAdmin(connectionFactory());
    }

    @Bean
    public RabbitTemplate rabbitTemplate() {
        return new RabbitTemplate(connectionFactory());
    }

    @Bean
    public Queue myQueue() {
       return new Queue("myqueue");
    }
}

A new testing support library is now provided. See Section 3.4, “Testing Support” for more information.

Builders are now available providing a fluent API for configuring Queue and Exchange objects. See the section called “Builder API for Queues and Exchanges” for more information.

See Section 3.1.15, “Message Listener Container Configuration” (autoDeclare) for some changes to the semantics of that option with respect to the use of RabbitAdmin s in the application context.

A number of new receive() methods with timeout have been introduced for the AmqpTemplate and its RabbitTemplate implementation. See the section called “Polling Consumer” for more information.

A new AsyncRabbitTemplate has been introduced. This template provides a number of send and receive methods, where the return value is a ListenableFuture, which can be used later to obtain the result either synchronously, or asynchronously. See the section called “AsyncRabbitTemplate” for more information.

1.4.1 introduced the ability to use Direct reply-to when the broker supports it; it is more efficient than using a temporary queue for each reply. This version allows you to override this default behavior and use a temporary queue by setting the useTemporaryReplyQueues property to true. See the section called “RabbitMQ Direct reply-to” for more information.

The RabbitTemplate now supports a user-id-expression (userIdExpression when using Java configuration). See Validated User-ID RabbitMQ documentation and the section called “Validated User Id” for more information.

Spring AMQP now has first class support for the RabbitMQ Delayed Message Exchange plugin. See Section 3.1.11, “Delayed Message Exchange” for more information.

Any Exchange definitions can now be marked as internal and the RabbitAdmin will pass the value to the broker when declaring the exchange. See Section 3.1.10, “Configuring the broker” for more information.

The factory bean now exposes a property to add client connection properties to connections made by the resulting factory.

A "white list" of allowable classes can now be configured when using Java deserialization. It is important to consider creating a white list if you accept messages with serialized java objects from untrusted sources. See the section called “Java Deserialization” for more information.

Improvements to the JSON message converter now allow the consumption of messages that don’t have type information in message headers. See the section called “Message Conversion for Annotated Methods” and the section called “Jackson2JsonMessageConverter” for more information.