Spring Webflex: Push Server Sent Event to Specific Users - spring

Question

I have been following this for reference. I am developing a spring-boot app which will have authenticated users. Once logged in, a user will subscribe to an event by visiting a specific URL.
This spring-boot app will also either support MQTT (or maybe just HTTP requests) in which information for a specific user will be sent. I would like to then display this sent information to the user using web flux/SSE if the user has subscribed.
Many users can be logged in at any given time, and they will have all subscribed to the updates. How do I manage all the different sinks for each logged in user?
I believe it's possible to get the current user when they visit the authenticated URL, but what's a method of storing all of the sinks for each logged in user?
I appreciate it.

Answer 1

You already got the answer in the comment section.
Lets assume that this is the message format you would be publishing.
public class Message {
private int intendedUserId;
private String message;
// getters and setters
}
Just have 1 processor and sink from the processor.
FluxProcessor<Message> processor;
FluxSink<Message> sink;
Push all the messages via the sink.
sink.next(msg);
Your controller would be more or less like this. Here I assume you have some method to get the user id authtoken.getUserId(). Here the filter is part of the Flux.
#GetMapping(value = "/msg", produces = MediaType.TEXT_EVENT_STREAM_VALUE)
public Flux<Message> getMessages(){
return processer
.filter(msg -> msg.getIntendedUserId() == authtoken.getUserId());
}