Spring Cloud Stream multiple consumers for multiple event types in same kinesis stream

Question

High level overview: different types of events are published to the same kinesis stream: OrderCreated, OrderUpdated, CustomerCreated, etc.

Those messages are to be consumed by a Spring Cloud Stream application by writing some Consumer functions and exposing them as beans (Functional style).

I could expose a message handler as java.util.function.Consumer to process all those messages in the scenario the message format was similar to the following 'generic' one:

Message {
    String type;
    Object payload;
}

However, I want to know if I can have different message handlers/consumers to process each type of event from the same stream name, something like this:

@Bean
Consumer<OrderCreated> processOrderCreatedEvent(SomeReceiver receiver) {
    return receiver::receive;
}

@Bean
Consumer<OrderCreated> processCustomerCreatedEvent(SomeOtherReceiver receiver) {
    return receiver::receive;
}

  cloud:
    function:
      definition: processOrderCreatedEvent;processCustomerCreatedEvent
    stream:
      bindings:
        processOrderCreatedEvent-in-0:
          destination: 'events-stream-name'
        processCustomerCreatedEvent-in-0:
          destination: 'events-stream-name'

I have not been able to make this work, so not sure if this is possible.

Answer 1

I think you are looking for Event Routing feature - https://docs.spring.io/spring-cloud-stream/docs/3.2.5-SNAPSHOT/reference/html/spring-cloud-stream.html#_event_routing

You can have individual functions for each event type and than have routing function consume everything and distribute between the functions based on your routing instructions.