/** 
     * 扩展xstream，使其支持CDATA块 
     *  
     */  
    private static XStream xstream = new XStream(new XppDriver() {  
        public HierarchicalStreamWriter createWriter(Writer out) {  
            return new PrettyPrintWriter(out) {  
                // 对所有xml节点的转换都增加CDATA标记  
                boolean cdata = true;  
  
                @SuppressWarnings("unchecked")  
                public void startNode(String name,Class clazz) {  
                    super.startNode(name,clazz);  
                }  
  
                protected void writeText(QuickWriter writer,String text) {  
                    if (cdata) {  
                        writer.write("<![CDATA[");  
                        writer.write(text);  
                        writer.write("]]>");  
                    } else {  
                        writer.write(text);  
                    }  
                }  
            };  
        }  
    });  

 /** 
     * 图文消息对象转换成xml 
     *  
     * @param newsMessage 图文消息对象 
     * @return xml 
     */  
    public static String newsMessageToXml(NewsMessage newsMessage) {  
        xstream.alias("xml",newsMessage.getClass());  
        xstream.alias("item",new Article().getClass());  
        return xstream.toXML(newsMessage);  
    }  

/** 
     * 解析微信发来的请求（XML） 
     *  
     * @param request 
     * @return 
     * @throws Exception 
     */  
    @SuppressWarnings("unchecked")  
    public static Map<String,String> parseXml(HttpServletRequest request) {  
        // 将解析结果存储在HashMap中  
        Map<String,String> map = new HashMap<String,String>();  
  
        // 从request中取得输入流  
        InputStream inputStream;
		try {
			inputStream = request.getInputStream();
			SAXReader reader = new SAXReader();  
	        Document document = reader.read(inputStream);  
	        // 得到xml根元素  
	        Element root = document.getRootElement();  
	        // 得到根元素的所有子节点  
	        List<Element> elementList = root.elements();  
	  
	        // 遍历所有子节点  
	        for (Element e : elementList)  
	            map.put(e.getName(),e.getText());  
	  
	        // 释放资源  
	        inputStream.close();  
		} catch (IOException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}catch (DocumentException e1) {
			// TODO Auto-generated catch block
			e1.printStackTrace();
		}
       
        inputStream = null;  
  
        return map;  
    }