| /* |
| * Copyright (C) 2014 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 com.example.android.musicservicedemo.model; |
| |
| import android.media.MediaMetadata; |
| import android.os.AsyncTask; |
| |
| import com.example.android.musicservicedemo.utils.LogHelper; |
| |
| import org.json.JSONArray; |
| import org.json.JSONException; |
| import org.json.JSONObject; |
| |
| import java.io.BufferedInputStream; |
| import java.io.BufferedReader; |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.io.InputStreamReader; |
| import java.net.URLConnection; |
| import java.util.ArrayList; |
| import java.util.HashMap; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.concurrent.locks.ReentrantLock; |
| |
| /** |
| * Utility class to get a list of MusicTrack's based on a server-side JSON |
| * configuration. |
| */ |
| public class MusicProvider { |
| |
| private static final String TAG = "MusicProvider"; |
| |
| private static final String CATALOG_URL = "http://storage.googleapis.com/automotive-media/music.json"; |
| |
| public static final String CUSTOM_METADATA_TRACK_SOURCE = "__SOURCE__"; |
| |
| private static String JSON_MUSIC = "music"; |
| private static String JSON_TITLE = "title"; |
| private static String JSON_ALBUM = "album"; |
| private static String JSON_ARTIST = "artist"; |
| private static String JSON_GENRE = "genre"; |
| private static String JSON_SOURCE = "source"; |
| private static String JSON_IMAGE = "image"; |
| private static String JSON_TRACK_NUMBER = "trackNumber"; |
| private static String JSON_TOTAL_TRACK_COUNT = "totalTrackCount"; |
| private static String JSON_DURATION = "duration"; |
| |
| private final ReentrantLock initializationLock = new ReentrantLock(); |
| |
| // Categorized caches for music track data: |
| private final HashMap<String, List<MediaMetadata>> mMusicListByGenre; |
| private final HashMap<String, MediaMetadata> mMusicListById; |
| |
| private final HashSet<String> mFavoriteTracks; |
| |
| enum State { |
| NON_INITIALIZED, INITIALIZING, INITIALIZED; |
| } |
| |
| private State mCurrentState = State.NON_INITIALIZED; |
| |
| |
| public interface Callback { |
| void onMusicCatalogReady(boolean success); |
| } |
| |
| public MusicProvider() { |
| mMusicListByGenre = new HashMap<>(); |
| mMusicListById = new HashMap<>(); |
| mFavoriteTracks = new HashSet<>(); |
| } |
| |
| /** |
| * Get an iterator over the list of genres |
| * |
| * @return |
| */ |
| public Iterable<String> getGenres() { |
| if (mCurrentState != State.INITIALIZED) { |
| return new ArrayList<String>(0); |
| } |
| return mMusicListByGenre.keySet(); |
| } |
| |
| /** |
| * Get music tracks of the given genre |
| * |
| * @return |
| */ |
| public Iterable<MediaMetadata> getMusicsByGenre(String genre) { |
| if (mCurrentState != State.INITIALIZED || !mMusicListByGenre.containsKey(genre)) { |
| return new ArrayList<MediaMetadata>(); |
| } |
| return mMusicListByGenre.get(genre); |
| } |
| |
| /** |
| * Very basic implementation of a search that filter music tracks which title containing |
| * the given query. |
| * |
| * @return |
| */ |
| public Iterable<MediaMetadata> searchMusics(String titleQuery) { |
| ArrayList<MediaMetadata> result = new ArrayList<>(); |
| if (mCurrentState != State.INITIALIZED) { |
| return result; |
| } |
| titleQuery = titleQuery.toLowerCase(); |
| for (MediaMetadata track: mMusicListById.values()) { |
| if (track.getString(MediaMetadata.METADATA_KEY_TITLE).toLowerCase() |
| .contains(titleQuery)) { |
| result.add(track); |
| } |
| } |
| return result; |
| } |
| |
| public MediaMetadata getMusic(String mediaId) { |
| return mMusicListById.get(mediaId); |
| } |
| |
| public void setFavorite(String mediaId, boolean favorite) { |
| if (favorite) { |
| mFavoriteTracks.add(mediaId); |
| } else { |
| mFavoriteTracks.remove(mediaId); |
| } |
| } |
| |
| public boolean isFavorite(String musicId) { |
| return mFavoriteTracks.contains(musicId); |
| } |
| |
| public boolean isInitialized() { |
| return mCurrentState == State.INITIALIZED; |
| } |
| |
| /** |
| * Get the list of music tracks from a server and caches the track information |
| * for future reference, keying tracks by mediaId and grouping by genre. |
| * |
| * @return |
| */ |
| public void retrieveMedia(final Callback callback) { |
| |
| if (mCurrentState == State.INITIALIZED) { |
| // Nothing to do, execute callback immediately |
| callback.onMusicCatalogReady(true); |
| return; |
| } |
| |
| // Asynchronously load the music catalog in a separate thread |
| new AsyncTask() { |
| @Override |
| protected Object doInBackground(Object[] objects) { |
| retrieveMediaAsync(callback); |
| return null; |
| } |
| }.execute(); |
| } |
| |
| private void retrieveMediaAsync(Callback callback) { |
| initializationLock.lock(); |
| |
| try { |
| if (mCurrentState == State.NON_INITIALIZED) { |
| mCurrentState = State.INITIALIZING; |
| |
| int slashPos = CATALOG_URL.lastIndexOf('/'); |
| String path = CATALOG_URL.substring(0, slashPos + 1); |
| JSONObject jsonObj = parseUrl(CATALOG_URL); |
| |
| JSONArray tracks = jsonObj.getJSONArray(JSON_MUSIC); |
| if (tracks != null) { |
| for (int j = 0; j < tracks.length(); j++) { |
| MediaMetadata item = buildFromJSON(tracks.getJSONObject(j), path); |
| String genre = item.getString(MediaMetadata.METADATA_KEY_GENRE); |
| List<MediaMetadata> list = mMusicListByGenre.get(genre); |
| if (list == null) { |
| list = new ArrayList<>(); |
| } |
| list.add(item); |
| mMusicListByGenre.put(genre, list); |
| mMusicListById.put(item.getString(MediaMetadata.METADATA_KEY_MEDIA_ID), |
| item); |
| } |
| } |
| mCurrentState = State.INITIALIZED; |
| } |
| } catch (RuntimeException | JSONException e) { |
| LogHelper.e(TAG, e, "Could not retrieve music list"); |
| } finally { |
| if (mCurrentState != State.INITIALIZED) { |
| // Something bad happened, so we reset state to NON_INITIALIZED to allow |
| // retries (eg if the network connection is temporary unavailable) |
| mCurrentState = State.NON_INITIALIZED; |
| } |
| initializationLock.unlock(); |
| if (callback != null) { |
| callback.onMusicCatalogReady(mCurrentState == State.INITIALIZED); |
| } |
| } |
| } |
| |
| private MediaMetadata buildFromJSON(JSONObject json, String basePath) throws JSONException { |
| String title = json.getString(JSON_TITLE); |
| String album = json.getString(JSON_ALBUM); |
| String artist = json.getString(JSON_ARTIST); |
| String genre = json.getString(JSON_GENRE); |
| String source = json.getString(JSON_SOURCE); |
| String iconUrl = json.getString(JSON_IMAGE); |
| int trackNumber = json.getInt(JSON_TRACK_NUMBER); |
| int totalTrackCount = json.getInt(JSON_TOTAL_TRACK_COUNT); |
| int duration = json.getInt(JSON_DURATION) * 1000; // ms |
| |
| LogHelper.d(TAG, "Found music track: ", json); |
| |
| // Media is stored relative to JSON file |
| if (!source.startsWith("http")) { |
| source = basePath + source; |
| } |
| if (!iconUrl.startsWith("http")) { |
| iconUrl = basePath + iconUrl; |
| } |
| // Since we don't have a unique ID in the server, we fake one using the hashcode of |
| // the music source. In a real world app, this could come from the server. |
| String id = String.valueOf(source.hashCode()); |
| |
| // Adding the music source to the MediaMetadata (and consequently using it in the |
| // mediaSession.setMetadata) is not a good idea for a real world music app, because |
| // the session metadata can be accessed by notification listeners. This is done in this |
| // sample for convenience only. |
| return new MediaMetadata.Builder() |
| .putString(MediaMetadata.METADATA_KEY_MEDIA_ID, id) |
| .putString(CUSTOM_METADATA_TRACK_SOURCE, source) |
| .putString(MediaMetadata.METADATA_KEY_ALBUM, album) |
| .putString(MediaMetadata.METADATA_KEY_ARTIST, artist) |
| .putLong(MediaMetadata.METADATA_KEY_DURATION, duration) |
| .putString(MediaMetadata.METADATA_KEY_GENRE, genre) |
| .putString(MediaMetadata.METADATA_KEY_ALBUM_ART_URI, iconUrl) |
| .putString(MediaMetadata.METADATA_KEY_TITLE, title) |
| .putLong(MediaMetadata.METADATA_KEY_TRACK_NUMBER, trackNumber) |
| .putLong(MediaMetadata.METADATA_KEY_NUM_TRACKS, totalTrackCount) |
| .build(); |
| } |
| |
| /** |
| * Download a JSON file from a server, parse the content and return the JSON |
| * object. |
| * |
| * @param urlString |
| * @return |
| */ |
| private JSONObject parseUrl(String urlString) { |
| InputStream is = null; |
| try { |
| java.net.URL url = new java.net.URL(urlString); |
| URLConnection urlConnection = url.openConnection(); |
| is = new BufferedInputStream(urlConnection.getInputStream()); |
| BufferedReader reader = new BufferedReader(new InputStreamReader( |
| urlConnection.getInputStream(), "iso-8859-1"), 8); |
| StringBuilder sb = new StringBuilder(); |
| String line = null; |
| while ((line = reader.readLine()) != null) { |
| sb.append(line); |
| } |
| return new JSONObject(sb.toString()); |
| } catch (Exception e) { |
| LogHelper.e(TAG, "Failed to parse the json for media list", e); |
| return null; |
| } finally { |
| if (is != null) { |
| try { |
| is.close(); |
| } catch (IOException e) { |
| // ignore |
| } |
| } |
| } |
| } |
| } |