Ajax传递特殊字符的数据如何解决

req.setRequestHeader("Content-Type",
        "application/x-www-form-urlencoded");

 //进行json数据的接收
    StringBuilder sb = new StringBuilder();
    BufferedReader br = request.getReader();
    char[] buff = new char[10000];
    int len;
    while((len = br.read(buff)) != -1){
      sb.append(buff, 0, len);
    }
    String mess = sb.toString();
    //将字符串转换为JSON对象
    JSONObject jsonObject=new JSONObject(mess);
    //获取其中的值
    jsonObject.getInt("Id");
    //含有特殊字符的文本需要先进行转码
    URLDecoder.decode(jsonObject.getString("text"), "UTF-8"));