Why not dedicated topics per action

[ghost]

Instead of enum for message action, would it not be more appropriate to have a channel per action. This affords dedicated subscribers without conditioning as well as not consuming messages it is not concerned with.

MessageAction is not necessary.

[ghost]

This switch statement is not ideal: MessageListenerService

Why consume all messages. I don't think this is common practice and is more likely to use topic/queue per desired action.