code: /*
   * Copyright 2015 Google Inc. All rights reserved.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.physical_web.collection;
  
  import org.json.JSONException;
  import org.json.JSONObject;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.OutputStream;
  import java.net.HttpURLConnection;
  import java.net.MalformedURLException;
  
  /**
   * A class that represents an HTTP request for a JSON object.
   * Both the request payload and the response are JSON objects.
   */
  class JsonObjectRequest extends Request<JSONObject> {
    private JSONObject mJsonObject;
  
    /**
     * Construct a JSON object request.
     * @param url The url to make this HTTP request to.
     * @param jsonObject The JSON payload.
     * @param callback The callback run when the HTTP response is received.
     * @throws MalformedURLException on invalid url
     */
    public JsonObjectRequest(String url, JSONObject jsonObject, RequestCallback callback)
        throws MalformedURLException {
      super(url, callback);
      mJsonObject = jsonObject;
    }
  
    /**
     * The callback that gets run after the request is made.
     */
    public interface RequestCallback extends Request.RequestCallback<JSONObject> {}
  
    /**
     * Helper method to make an HTTP request.
     * @param urlConnection The HTTP connection.
     */
    public void writeToUrlConnection(HttpURLConnection urlConnection) throws IOException {
      urlConnection.setDoOutput(true);
      urlConnection.setRequestProperty("Content-Type", "application/json");
      urlConnection.setRequestProperty("Accept", "application/json");
      urlConnection.setRequestMethod("POST");
      OutputStream os = urlConnection.getOutputStream();
      os.write(mJsonObject.toString().getBytes("UTF-8"));
      os.close();
    }
  
    /**
     * Helper method to read an HTTP response.
     * @param is The InputStream.
     * @return An object representing the HTTP response.
     */
    protected JSONObject readInputStream(InputStream is) throws IOException {
      StringBuilder stringBuilder = new StringBuilder();
      BufferedReader in = new BufferedReader(new InputStreamReader(is, "UTF-8"));
      String line;
      while ((line = in.readLine()) != null) {
          stringBuilder.append(line);
      }
      JSONObject jsonObject;
      try {
          jsonObject = new JSONObject(stringBuilder.toString());
      } catch (JSONException error) {
          throw new IOException(error.toString());
      }
      return jsonObject;
    }
  }
  