code: /*
   * Copyright 2016 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 java.io.ByteArrayOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.HttpURLConnection;
  import java.net.MalformedURLException;
  
  /**
   * A class that represents an HTTP request for an image.
   * The response is a byte array of bitmap data.
   */
  class BitmapRequest extends Request<byte[]> {
    /**
     * Construct a bitmap HTTP request.
     * @param url The url to make this HTTP request to.
     * @param callback The callback run when the HTTP response is received.
     *     The callback can be called with a null bitmap if the image
     *     couldn't be decoded.
     * @throws MalformedURLException on invalid url
     */
    public BitmapRequest(String url, RequestCallback callback) throws MalformedURLException {
      super(url, callback);
    }
  
    /**
     * The callback that gets run after the request is made.
     */
    public interface RequestCallback extends Request.RequestCallback<byte[]> {}
  
    /**
     * Helper method to make an HTTP request.
     * @param urlConnection The HTTP connection.
     */
    public void writeToUrlConnection(HttpURLConnection urlConnection) throws IOException {}
  
    /**
     * Helper method to read an HTTP response.
     * @param is The InputStream.
     * @return The decoded image.
     */
    protected byte[] readInputStream(InputStream is) throws IOException {
      ByteArrayOutputStream os = new ByteArrayOutputStream();
      byte[] buffer = new byte[1024];
      int len;
      while ((len = is.read(buffer)) != -1) {
        os.write(buffer, 0, len);
      }
      return os.toByteArray();
    }
  }
  