title: How to get Session Id in Spring WebSocketStompClient?
body: <p>How to get session id in Java Spring WebSocketStompClient?</p>
  
  <p>I have WebSocketStompClient and StompSessionHandlerAdapter, which instances connect fine to websocket on my server. WebSocketStompClient use SockJsClient.<br>
  But I don't know how get session id of websocket connection. In the code with stomp session handler on client side</p>
  
  <pre><code>   private class ProducerStompSessionHandler extends StompSessionHandlerAdapter {
              ...
              @Override
              public void afterConnected(StompSession session, StompHeaders  connectedHeaders) {
              ...
              }
  </code></pre>
  
  <p>stomp session contains session id, which is different from session id on the server. 
  So from this ids: </p>
  
  <pre><code>DEBUG ... Processing SockJS open frame in WebSocketClientSockJsSession[id='d6aaeacf90b84278b358528e7d96454a...
  
  DEBUG ... DefaultStompSession - Connection established in session id=42e95c88-cbc9-642d-2ff9-e5c98fb85754
  </code></pre>
  
  <p>I need first session id, from WebSocketClientSockJsSession.
  But I didn't found in WebSocketStompClient or SockJsClient any method to retrieve something like session id...</p>