Robbo_UK Robbo_UK - 1 year ago 407
Java Question

rabbitmq consume json message and convert into Java object

I have put together a java test. It puts a message on a queue and returns it as a string. What Im trying to achieve is for it to it convert into the java object SignUpDto. I have stripped down the code as much as possible for the question.

The question:

How do I modify the test below to convert into a object?


public class SignUpDto {
private String customerName;
private String isoCountryCode;
... etc

Application - Config class

public class Application {

public ConnectionFactory connectionFactory() {
return new CachingConnectionFactory("localhost");

public AmqpAdmin amqpAdmin() {
return new RabbitAdmin(connectionFactory());

public RabbitTemplate rabbitTemplate() {

// updated with @GaryRussels feedback
RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory());
rabbitTemplate.setMessageConverter(new Jackson2JsonMessageConverter());
return rabbitTemplate;

public Queue myQueue() {
return new Queue("myqueue");

The Test

@ContextConfiguration(classes = {Application.class})
public class TestQueue {

public void convertMessageIntoObject(){

ApplicationContext context = new AnnotationConfigApplicationContext(Application.class);
AmqpTemplate template = context.getBean(AmqpTemplate.class);

String jsonString = "{ \"customerName\": \"TestName\", \"isoCountryCode\": \"UK\" }";

template.convertAndSend("myqueue", jsonString);

String foo = (String) template.receiveAndConvert("myqueue");

// this works ok

// How do I make this convert
//SignUpDto objFoo = (SignUpDto) template.receiveAndConvert("myqueue");
// objFoo.toString()


Answer Source

Configure the RabbitTemplate with a Jackson2JsonMessageConverter.

Then use

template.convertAndSend("myqueue", myDto);


SignUpDto out = (SignUpDto) template.receiveAndConvert("myQueue");

Note that the outbound conversion sets up the content type (application/json) and headers with type information that tells the receiving converter what object type to create.

If you really do want to send a simple String of JSON, you need to set the content type to application/json. To help the inbound conversion, you can either set the type headers (look at the converter source for information), or you can configure the converter with a ClassMapper to determine the type.


<rabbit:template id="amqpTemplate" connection-factory="connectionFactory"
         message-converter="json" />

<bean id="json"
 class="" />

Or, since you are using Java Config; simply inject one into your template definition.


If you want to send a plain JSON string; you need to help the inbound converter via headers.

To set the headers...

template.convertAndSend("", "myQueue", jsonString, new MessagePostProcessor() {

    public Message postProcessMessage(Message message) throws AmqpException {
            .put(AbstractJavaTypeMapper.DEFAULT_CLASSID_FIELD_NAME, "foo.SignUpDto");
        return message;

Bear in mind, though, that this sending template must NOT have a JSON message converter (let it default to the SimpleMessageConverter). Otherwise, the JSON will be double-encoded.

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