SpringCloudDemo | Spring Boot 2.0.6 Spring Cloud Finchley.SR2 | Microservice library

There are few things that are wrong with your application

1. Why are you injecting Processor in your application? I mean the whole purpose for it is to signal to the framework to create necessary bindings to bridge/map local channels with remote destinations (Kafka, Rabbit etc). This means that when you send message to the input channel directly you are completely bypassing spring-cloud-stream framework and all its features including error handling, message conversion, retries etc. Basically at that point you are simply NOT using spring-cloud-stream. When you throw an exception the exception is propagated back to the original caller. In the case of spring-cloud-stream the original caller is message listening container which catches exception, does retries and then goes through error handling routine including sending to error channel(s). In your case the original caller is you via source.input().send(...), not the framework.

2. The signature here is wrong: @ServiceActivator(inputChannel="errorChannel") public ErrorMessage onError(ErrorMessage message). By returning anything other than void what are your expectations? Where would the ErrorMessage go?