将Object对象转成 json串

    /**
     * 将对象分装为json字符串 (json + 递归)
     * @param obj 参数应为{@link java.util.Map} 或者 {@link java.util.List}
     * @return
     */
    @SuppressWarnings("unchecked")
    public static Object jsonEnclose(Object obj) {
        try {
            if (obj instanceof Map) {   //如果是Map则转换为JsonObject
                Map<String, Object> map = (Map<String, Object>)obj;
                Iterator<Entry<String, Object>> iterator = map.entrySet().iterator();
                JSONStringer jsonStringer = new JSONStringer().object();
                while (iterator.hasNext()) {
                    Entry<String, Object> entry = iterator.next();
                    jsonStringer.key(entry.getKey()).value(jsonEnclose(entry.getValue()));
                }
                JSONObject jsonObject = new JSONObject(new JSONTokener(jsonStringer.endObject().toString()));
                return jsonObject;
            } else if (obj instanceof List) {  //如果是List则转换为JsonArray
                List<Object> list = (List<Object>)obj;
                JSONStringer jsonStringer = new JSONStringer().array();
                for (int i = 0; i < list.size(); i++) {
                    jsonStringer.value(jsonEnclose(list.get(i)));
                }
                JSONArray jsonArray = new JSONArray(new JSONTokener(jsonStringer.endArray().toString()));
                return jsonArray;
            } else {
                return obj;
            }
        } catch (Exception e) {
            Log.e("jsonUtil--Enclose", e.getMessage());
            return e.getMessage();
        }
    }