How does Rsocket server send message to client? And how to use Channel in js?

Question

everyone.

Question 1

I try to use Rsocket. How does Rsocket server send message to client? Like websocket, the server can send message to one client or all clients. I can not find a way to do it. Maybe I can use Channel? But I do not know what to do.

Question 2

I use Channel like this:

  @MessageMapping("channel")
  fun channel(settings: Flux<Duration>) =
      settings
          .doOnNext { setting: Duration -> println("Frequency setting is ${setting.seconds} second(s).") }
          .switchMap { setting: Duration ->
            Flux.interval(setting).map { index: Long -> Message("Server", "Channel", index) }
          }
          .log()

And in js, I do this:

const {
  RSocketClient
} = require('rsocket-core');
const RSocketTcpClient = require('rsocket-tcp-client').default;
const {Flowable} = require('rsocket-flowable')

const tcpClient = new RSocketTcpClient((host, port))

const client = new RSocketClient({
  setup: {
    keepAlive,
    lifetime,
    dataMimeType: "application/json",
    metadataMimeType: 'message/x.rsocket.routing.v0'
  },
  transport: tcpClient,
});

const flowablePayload = new Flowable(subscriber => {
  subscriber.onSubscribe({
    cancel: () => {},
    request: n => {
      for (let index = 0; index < n; index++) {
        const message = {
          message: "requestChannel from JavaScript! #" + index
        };
        subscriber.onNext(message);
      }
      subscriber.onComplete();
    }
  });
});    

client.connect().subscribe({
  onComplete: socket => {
    console.log('onComplete')
    socket.requestChannel({
      data: flowablePayload,
      metadata: String.fromCharCode('channel'.length) + 'channel'
    }).subscribe({
      onComplete: res => console.log(res),
      onError: err => console.error(err)，
      onSubscribe: cancel => console.log('success')
    });
  },
  onError: error => {
    console.log("got error");
    console.error(error);
  },
  onSubscribe: cancel => {
    console.log("subscribe!");
  }
})

output:

subscribe!
onComplete
success

But I can not get the MessageMapping channel info and channel method is not executed.

What should I do？

Thanks!!!

hi @EchoCow, I'm struggling exactly the same issue as you. Can we chat about it, maybe we will be able to figure it out. https://chat.stackoverflow.com/rooms/212325/rsocket-with-spring-webflux — kojot, Apr 23 '20 at 07:50

score 0 · Answer 1 · answered Apr 27 '20 at 06:12

Question 1: If you want to know how to send a message to a certain client, please see this StackOverflow question Send message only to certain client using websockets with Rsocket and Spring Webflux

Question 2: I've never tried using the channels, but I'm not sure you really need it. I would use the channel for example in an online game, where the user constantly pushes the keys and the server has to respond to them.

How does Rsocket server send message to client? And how to use Channel in js?

Question 1

Question 2

1 Answers1