Parser

GsonBuilder gson = new GsonBuilder();
gson.registerTypeAdapter(ResponseMessage.class, new UsingTimeDataTypeAdapter());
return gson.create().fromJson(result, ResponseMessage.class);

TimeDataTypeAdapter

public class TimeDataTypeAdapter extends TypeAdapter<ResponseMessage> {

    @Override
    public void write(JsonWriter out, ResponseMessage valueList) throws IOException {
        // 처리 하지 않음
    }

    @Override
    public ResponseMessage read(JsonReader in) throws IOException {

        JsonParser parser = new JsonParser();
        JsonObject bodyObject = parser.parse(in).getAsJsonObject().getAsJsonObject("body");

        String result = bodyObject.get("result").getAsString();
        String message = bodyObject.get("message").getAsString();

        if (!TextUtils.equals("200", result)) {
            MessageBody body = new MessageBody(new HashMap<Object, Object>());
            body.setMessage(message);
            body.setResult(result);
            return new ResponseMessage(body);
        }

        // 그래프에 표시될 최고 값
        int maxTime = 0;

        // 전체 자녀 사용자 7일간 평균 사용시간 파싱
        JsonArray timeAverageList = bodyObject.getAsJsonObject("data").getAsJsonArray("timeAverageList");
        ArrayList<TimeTO> timeAverageTOs = new ArrayList<TimeTO>();

        for (int idx = 0, size = timeAverageList.size(); idx < size; ++idx) {
            TimeTO timeTO = new TimeTO();
            JsonObject tempTimeObject = timeAverageList.get(idx).getAsJsonObject();

            String date = tempTimeObject.get("date").getAsString();
            int time = tempTimeObject.get("time").getAsInt();

            if (time > maxTime) {
                maxTime = time;
            }

            timeTO.setDate(date);
            timeTO.setTime(time);

            timeAverageTOs.add(timeTO);
        }

        HashMap<Object, Object> data = new HashMap<Object, Object>();
        data.put("timeAverageList", timeAverageTOs);
        data.put("maxTime", maxTime);

        MessageBody body = new MessageBody(data);
        body.setMessage(message);
        body.setResult(result);
        return new ResponseMessage(body);
    }
}