spring mvc接收微信发送xml数据始终不成功?

    public static Map<String, String> xmlToMap(HttpServletRequest request) throws IOException {
                Map<String, String> map = new HashMap<String, String>();
                SAXReader reader = new SAXReader();

                InputStream ins = null;
                try {
                        ins = request.getInputStream();
                } catch (IOException e1) {
                        e1.printStackTrace();
                }
                Document doc = null;
                try {
                        doc = reader.read(ins);
                        Element root = doc.getRootElement();

                        List<Element> list = root.elements();

                        for (Element e : list) {
                                map.put(e.getName(), e.getText());
                        }

                        return map;
                } catch (DocumentException e1) {
                        e1.printStackTrace();
                }finally{
                        ins.close();
                }

                return null;
        }

	// xml请求解析
			Map<String, String> requestMap = MessageUtil.xmlToMap(request);

			// 发送方帐号（open_id）
			String fromUserName = requestMap.get("FromUserName");
			// 公众帐号
			String toUserName = requestMap.get("ToUserName");
			// 消息类型
			String msgType = requestMap.get("MsgType");
			// 消息内容
			String content = requestMap.get("Content");

			logger.info(
					"FromUserName is:" + fromUserName + ", ToUserName is:" + toUserName + ", MsgType is:" + msgType);

后面判断消息类型是文本还是图像等