Patreon Refresh

public static void refreshPatreonToken(String clientID, String clientSecret, String refreshToken, List<String> contents) {
        try {
            String refreshURL = "http://www.patreon.com/api/oauth2/";
            String urlArgs = String.format("token?grant_type=refresh_token&refresh_token=%s&client_id=%s&client_secret=%s", refreshToken, clientID, clientSecret);
            URL url = new URL(refreshURL);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("POST");
            connection.setRequestProperty("User-Agent", "Mozilla/5.0");
            connection.setRequestProperty("Accept-Language", "en-US,en;q=0.5");
            connection.setDoOutput(true);
            connection.connect();
            DataOutputStream write = new DataOutputStream(connection.getOutputStream());
            write.writeBytes(urlArgs);
            write.flush();
            write.close();

            logger.info("Sending request to refresh token.");
            if (connection.getResponseCode() == HttpURLConnection.HTTP_OK) {
                InputStream stream = connection.getInputStream();
                Reader reader = new InputStreamReader(stream, StandardCharsets.UTF_8);
                JsonParser parser = new JsonParser();
                JsonElement jsonElement = parser.parse(reader);
                reader.close();
                stream.close();
                Gson gson = new Gson();
                TokenRefreshObject object = gson.fromJson(jsonElement, TokenRefreshObject.class);
                if (object != null) {
                    logger.info("Token Refreshed");
                    contents.set(0, object.getAccessToken());
                }
            }
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }