servlet中常用到的工具

1. 解析ajax传来的json字符串，得到json对象

 private JSONObject getJsonObject(HttpServletRequest req) {
         StringBuffer json=new StringBuffer();
         String lineString=null;
         BufferedReader reader;
         JSONObject data=null;
         try {
             reader = req.getReader();
             while((lineString=reader.readLine())!=null) {
                 json.append(lineString);
             }
              data=JSONObject.fromObject(json.toString());
         } catch (IOException e) {
             e.printStackTrace();
         }
         return data;
     }