CODEWITHSUNDEEP
jsonspring-cloudspring-rabbitspring-cloud-stream
wst
wst

Reputation: 4338

Spring Cloud Stream message from/to JSON conversion configuration

I am using Spring Cloud Stream, with RabbitMQ binder. It works great with byte[] payload and Java native serialization, but I need to work with JSON payload.

Here's my processor class.

@EnableBinding(Processor.class)
public class MessageProcessor {
    @ServiceActivator(inputChannel = Processor.INPUT, outputChannel = Processor.OUTPUT)
    public OutputDto handleIncomingMessage(InputDto inputDto) {
        // Run some job.
        return new OutputDto();
    }
}

InputDto and OutputDto are POJOs with Jackson annotations.

Upvotes: 5

Views: 10014

Answers (1)

Dave Syer
Dave Syer

Reputation: 58114

In your consumer you can add a content type configuration, e.g.

spring.cloud.stream.bindings.input.content-type: application/x-java-object;type=my.package.InputDto

You could also add 

spring.cloud.stream.bindings.output.content-type: application/json

to force the outgoing message payload to be JSON (for interop etc.).

Note that "input" and "output" are the binder channel names (i.e. as defined in Processor in your app).

I think there is a good chance this could be made easier or more automatic, but there is some engineering effort required to make that happen in Spring Cloud. There's an issue in github if you want to follow it: https://github.com/spring-cloud/spring-cloud-stream/issues/156.

To send a message manually to a Spring Cloud Stream you can set the headers up yourself manually (but it's easier to use a Stream). A JSON message looks like this in the Rabbit admin UI:

priority:   0
delivery_mode:  2
headers:    
    contentType:    text/plain
    originalContentType:    application/json
content_type:   text/plain

Upvotes: 8

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