title: Stomp WebSocket subscribe to two different topics
body: <p>I have one websocket server and one websocket client both in Java. The websocket server has this:</p>
  
  <pre><code>@MessageMapping("/hello")
  @SendTo("/topic/greetings")
  public Greeting greeting(final HelloMessage message) throws Exception {
      Thread.sleep(1000); // simulated delay
      return new Greeting("Hello, " + message.getName() + "!");
  }
  </code></pre>
  
  <p>And in the Java WebSocket client I have the following in my StompSessionHandler.afterConnected:</p>
  
  <pre><code>session.subscribe("/topic/greetings", stompFrameHandler)
  </code></pre>
  
  <p>Then, I am able to communicate between the two by, the client sending a message to the server path "hello" and then since the client is subscribed to "topic/greetings", I am also to handle the response with my stompFrameHandler.</p>
  
  <p>But I am wondering if it is possible for a client to subscribe to two different "channels", so something like this in StompSessionHandler.afterConnected:</p>
  
  <pre><code>session.subscribe("/topic/greetings", greetingsFrameHandler)
  session.subscribe("/topic/farewell", farewellFrameHandler)
  </code></pre>
  
  <p>Because I tried and I can only receive events from topic/greetings, but not for topic/farewell. I do not know if this is important, but to trigger a farewell event I make a rest call to the websocket server:</p>
  
  <pre><code>@PostMapping(value = "/sendFarewellEvent", produces = MediaType.APPLICATION_JSON_VALUE)
  @ResponseBody
  @SendTo("/topic/farewell")
  public Farewell farewell(@RequestBody final Farewell farewell) throws Exception {
      Thread.sleep(1000); // simulated delay
      return farewell;
  }
  </code></pre>