Does @EnableBinding annotation disable the Functional Approach automatically?

Question

I have a microservice that utilizes a custom binder, CustomBinderA, and a declarative approach. In the code, you can find several classes with annotations like @EnableBinding, @Input, @StreamListener, and so on. Everything works fine.

Recently, I implemented another binder, CustomBinderB, and tested it on a different microservice using the latest functional approach, and everything worked well there too.

Now, I am attempting to integrate the new binder into the previous microservice while still keeping the old one. Every configuration point is enabled, and everything should work. However, I noticed that only the explicitly declared bindings (i.e., those with the @Input annotation) are being instantiated.

So, the only thing I am trying to figure out is: can the functional approach and the declarative approach work together, or is there some way in which, if @EnableBinding is used, the properties related to the functional approach are being ignored?

I tried to combine both the configurations using the multibinder approach.

spring:
  cloud
    stream:
      function:
        definition: createOrderConsumer

      binders:
        CustomBinderB:
          type: custom-binder-b
        CustomBinderA:
          type: custom-binder-a


...
      bindings:
        createOrderConsumer-in-0:
          destination: createOrder
          binder: CustomBinderB
        outbox:
          destination: notifyOrder
          binder: CustomBinderA
        inbox:
          destination: inbox
          binder: CustomBinderA

I expected every bindable channel to be instantiated.

However, only the "inbox" and "outbox" channels are being instantiated, which are the ones explicitly declared using the @Input and @Output annotations.

Answer 1

EnableBinding and all related components, such as Input and Output etc., have been deprecated for a while now and completely removed from the recent versions of the framework (starting with 4.0.0). Therefore, we highly recommend to stop using EnableBinding in your application and migrate completely to the functional style. If you are using a version of Spring Cloud Stream that still supports EnableBinding, it is not advised to mix both styles in a single application.