@OnMessage public void onMessage(ByteBuffer buffer){
  if (messageHandler != null) {
    messageHandler.handleMessage(buffer);
  }
  fireWSHeartBitMonitorTimer();
}

@ OnMessage public void onMessage ( ByteBuffer buffer ) { if ( messageHandler != null ) { messageHandler . handleMessage ( buffer ) ; } fireWSHeartBitMonitorTimer ( ) ; }
callback hook for message events . this method will be invoked when a server send a binary message .
