2. Introduction

The minimum Spring Framework version dependency is 5.0.x.

The minimum amqp-client java client library version is 4.0.0.

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");
    }
}

Spring AMQP now uses the new 4.0.x version of the amqp-client library provided by the RabbitMQ team. This client has auto recovery configured by default; see the section called “RabbitMQ Automatic Connection/Topology recovery”.

The DirectMessageListenerContainer has been added alongside the existing SimpleMessageListenerContainer. See the section called “Choosing a Container” and Section 3.1.15, “Message Listener Container Configuration” for information about choosing which container to use as well as how to configure them.

This appender is no longer available due to the end-of-life of log4j. See Section 3.2, “Logging Subsystem AMQP Appenders” for information about the available log appenders.

	Important
	Previously, a non-transactional RabbitTemplate participated in an existing transaction if it ran on a transactional listener container thread. This was a serious bug; however, users might have relied on this behavior. Starting with version 1.6.2, you must set the channelTransacted boolean on the template for it to participate in the container transaction.

The RabbitTemplate now uses a DirectReplyToMessageListenerContainer (by default) instead of creating a new consumer for each request. See the section called “RabbitMQ Direct reply-to” for more information.

The AsyncRabbitTemplate now supports Direct reply-to; see the section called “AsyncRabbitTemplate” for more information.

A convenient FunctionalInterface is available for using lambdas with the MessageListenerAdapter. See the section called “MessageListenerAdapter” for more information.

Previously, MessageProperties.getMessageCount() returned 0 for messages emitted by the container. This property only applies when using basicGet (e.g. from RabbitTemplate.receive() methods) and is now initialized to null for container messages.

The connection and channel listener interfaces now provide a mechanism to obtain information about exceptions. See the section called “Connection and Channel Listeners” and the section called “Publishing is Asynchronous - How to Detect Success and Failures” for more information.

A new ConnectionNameStrategy is now provided to populate the application-specific identification of the target RabbitMQ connection from the AbstractConnectionFactory. See Section 3.1.2, “Connection and Resource Management” for more information.

The MissingMessageIdAdvice is no longer provided; it’s functionality is now built-in; see the section called “Failures in Synchronous Operations and Options for Retry” for more information.

By default, AnonymousQueues are now named with the default Base64UrlNamingStrategy instead of a simple UUID string. See the section called “AnonymousQueue” for more information.

You can now provide simple queue declarations (only bound to the default exchange) in @RabbitListener annotations. See the section called “Annotation-driven Listener Endpoints” for more information.

You can now configure @RabbitListener annotations so that any exceptions thrown will be returned to the sender. You can also configure a RabbitListenerErrorHandler to handle exceptions. See the section called “Handling Exceptions” for more information.