Android Autobahn请求。getHttpSession（）=null

客户端代码：

private void startPolling() {

        final String wsuri = MainAsync.WEB_SOCKET_HOST_WS+"/game";

        try {

            mConnection.connect(wsuri, new WebSocketHandler() {

                @Override
                public void onOpen() {
                    Log.d(TAG, "Status: Connected to " + wsuri);
                    int role = mAccMeth.loadId(getApplicationContext());
                    mConnection.sendTextMessage(String.valueOf(role));
                }

                @Override
                public void onTextMessage(String payload) {
                   Log.d(TAG, "Got echo: " + payload);

                }

                @Override
                public void onClose(int code, String reason) {
                   Log.d(TAG, "Connection lost.");
                }
            });
          } catch (WebSocketException e) {
              Log.d(TAG, e.toString());
          }
    }

服务器端实现：

@ServerEndpoint(value="/game",configurator = ServletConfig.class)
public class WebSocketPollingCoordinates   {

 EndpointConfig endConfig;

@OnMessage
    public void receiveMessage(String message,final Session session){
         HttpSession httpSession = (HttpSession) endConfig.getUserProperties().get("httpSession");
        //at this line i get NullpointerException
        final ServletContext sercntxt = (ServletContext)httpSession.getServletContext();
}

 @OnOpen
    public void onOpen(Session sn, EndpointConfig ec) {
        System.out.println("onOpen");
        this.endConfig = ec;
    }

  @OnError
   public void error(Session session, Throwable t) {
       t.printStackTrace();
   }

和WebSocket配置类：

公共类ServletConfig扩展配置程序{

 @Override
    public void modifyHandshake(ServerEndpointConfig config, HandshakeRequest request, HandshakeResponse response) {
        HttpSession httpSession = (HttpSession) request.getHttpSession();

        if(httpSession==null || config==null){
            if(httpSession==null)
                System.out.println("httpSession==null");
            if(config==null)
                System.out.println("config==null");
            return;
        }
        config.getUserProperties().put("httpSession", httpSession);
    }
}

我总是得到下一个结果：http会话==null。错误在哪里？我需要获取httpSession，以调用voidhttpSession.getServletContext（）；