得到json传来的“键和值”

JSONArray ja =null;
//ja从外面传来
JSONObject jo= JSONObject.fromObject(ja.get(i));
Iterator iter = jo.keys();
while(iter.hasNext()){
  String key1 = (String)iter.next();
        Object value1 = jo.get(key1);    
key += key1+"=?,";
        list.add(value1);
}