Submitting A Fire-N-Forget Request

Question

In a Spring Boot application, I have the following working code for submitting a request-response request in a Rest controller:

@GetMapping("/request-response")
public ResponseEntity<Mono<Message>> requestResponseCtr() throws InterruptedException {

    Mono<Message> message = this.rsocketRequesterMono.flatMap(
            requester -> requester.route("request-response")
                    .data(new Message(...))
                    .retrieveMono(Message.class)
                );
    log.info("\nResponse was: {}", message);

    return ResponseEntity.of(Optional.of(message));
}

Based on my understanding of the RSocket Java document, I need to replace the retriveveMono(...) with send() for submitting a fire-n-forget request (on page 12 of the document). The following code should work.

@GetMapping("fire-and-forget")
public ResponseEntity<Mono<Void>> fireAndForget() throws InterruptedException {
    log.info("\nFire-And-Forget...");

    this.rsocketRequesterMono.flatMap(
            requester -> requester.route("fire-and-forget")
                    .data(new Message(...))
                    .send()
    );
    return ResponseEntity.of(Optional.of(Mono.empty()));
}

It doesn't work, however. On a TCP debuting tool, there isn't any traffic for it.

What is the right way of submitting a fire-n-forget?

Answer 1

This call

this.rsocketRequesterMono.flatMap(
            requester -> requester.route("fire-and-forget")
                    .data(new Message(...))
                    .send()
    );

isn't doing anything because nothing is subscribing to it.

You likely need

ResponseEntity.of(Optional.of(this.rsocketRequesterMono.flatMap(
            requester -> requester.route("fire-and-forget")
                    .data(new Message(...))
                    .send()
    )));