Java tutorial
/* * Copyright (C) 2014 Fastboot Mobile, LLC. * * This program is free software; you can redistribute it and/or modify it under the terms of the * GNU General Public License as published by the Free Software Foundation; either version 3 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See * the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along with this program; * if not, see <http://www.gnu.org/licenses>. */ package com.fastbootmobile.encore.api.musicbrainz; import android.util.Log; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import com.fastbootmobile.encore.api.common.JsonGet; import com.fastbootmobile.encore.api.common.Pair; import com.fastbootmobile.encore.api.common.RateLimitException; import java.io.IOException; import java.net.URLEncoder; import java.util.HashMap; import java.util.Map; /** * MusicBrainz API Client */ public class MusicBrainzClient { private static final String TAG = "MusicBrainzClient"; private static final String MAIN_EP = "http://musicbrains.org/ws/2"; private static final String COVER_EP = "http://coverartarchive.org/release/"; private static final Map<Pair<String, String>, AlbumInfo[]> mAlbumInfoCache = new HashMap<>(); private static final Map<String, String> mAlbumArtCache = new HashMap<>(); /** * Retrieves the album information from MusicBrainz. This method is synchronous and must be * called from a Thread! * @param artist The name of the artist. Must be filled. * @param album The name of the album. May be empty. * @return An {@link com.fastbootmobile.encore.api.musicbrainz.AlbumInfo} filled with the information * from musicbrainz, or null in case of error */ public static AlbumInfo[] getAlbum(String artist, String album) throws RateLimitException { if (mAlbumInfoCache.containsKey(Pair.create(artist, album))) { return mAlbumInfoCache.get(Pair.create(artist, album)); } if (artist == null && album == null) { return null; } try { String query = ""; if (artist != null) { query += URLEncoder.encode("artist:\"" + artist + "\"", "UTF-8"); } if (album != null && !album.isEmpty()) { query += URLEncoder.encode(" AND release:\"" + album + "\"", "UTF-8"); } JSONObject object = JsonGet.getObject(MAIN_EP + "/release/", "fmt=json&query=" + query, true); if (object.has("releases")) { JSONArray releases = object.getJSONArray("releases"); final int releasesCount = releases.length(); if (releasesCount > 0) { AlbumInfo[] infoArray = new AlbumInfo[releasesCount]; for (int i = 0; i < releasesCount; i++) { AlbumInfo info = new AlbumInfo(); JSONObject release = releases.getJSONObject(i); info.id = release.getString("id"); try { info.track_count = release.getInt("track-count"); } catch (JSONException e) { // No track count info, too bad info.track_count = 0; } infoArray[i] = info; } mAlbumInfoCache.put(Pair.create(artist, album), infoArray); return infoArray; } } else if (object.has("error")) { Log.w(TAG, "Rate limited by the API, will retry later"); throw new RateLimitException(); } // AlbumArtCache will retry with something else if needed mAlbumInfoCache.put(Pair.create(artist, album), null); return null; } catch (IOException e) { Log.e(TAG, "Unable to get album info (rate limit?)", e); throw new RateLimitException(); } catch (JSONException e) { // May happen due to an API error, e.g. error 502 Log.e(TAG, "JSON error while parsing album info", e); throw new RateLimitException(); } } /** * Returns the URL to an image representing the album art of the provided album ID. This album * id must be retrieved with {@link #getAlbum(String, String)} * @param albumId The album ID * @return An album art URL, or null if none found */ public static String getAlbumArtUrl(String albumId) throws RateLimitException { if (mAlbumArtCache.containsKey(albumId)) { return mAlbumArtCache.get(albumId); } try { JSONObject object = JsonGet.getObject(COVER_EP + albumId, "", true); // We take the very first art here, no matter if it's front or back. Eventually some // day, we might filter only front art. JSONArray images = object.getJSONArray("images"); JSONObject image = images.getJSONObject(0); String output = image.getJSONObject("thumbnails").getString("large"); mAlbumArtCache.put(albumId, output); return output; } catch (IOException e) { mAlbumArtCache.put(albumId, null); return null; } catch (JSONException e) { mAlbumArtCache.put(albumId, null); return null; } } }