code: public void doPost(AtmosphereResource ar) {
          Object msg = ar.getRequest().getAttribute(Constants.MESSAGE_OBJECT);
          if (msg != null) {
            logger.info("received RPC post: " + msg.toString());
            // for demonstration purposes we will broadcast the message to all connections
              ar.getAtmosphereConfig().getBroadcasterFactory().lookup("MyBroadcaster").broadcast(msg);
          }
      }
docs: receive push message from client