src/main/java/net/pterodactylus/demoscenemusic/data/DataManager.java

   1 /*
   2  * DemosceneMusic - DataManager.java - Copyright © 2012 David Roden
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 package net.pterodactylus.demoscenemusic.data;
  19
  20 import java.sql.ResultSet;
  21 import java.sql.SQLException;
  22 import java.util.Collection;
  23 import java.util.EnumMap;
  24 import java.util.HashSet;
  25 import java.util.List;
  26 import java.util.Map;
  27 import java.util.Map.Entry;
  28 import java.util.UUID;
  29 import java.util.concurrent.Callable;
  30
  31 import net.pterodactylus.demoscenemusic.data.Track.Relationship;
  32 import net.pterodactylus.util.collection.Memoizer;
  33 import net.pterodactylus.util.database.Database;
  34 import net.pterodactylus.util.database.DatabaseException;
  35 import net.pterodactylus.util.database.Field;
  36 import net.pterodactylus.util.database.Join;
  37 import net.pterodactylus.util.database.Join.JoinType;
  38 import net.pterodactylus.util.database.ObjectCreator;
  39 import net.pterodactylus.util.database.ObjectCreator.StringCreator;
  40 import net.pterodactylus.util.database.OrderField;
  41 import net.pterodactylus.util.database.Parameter.IntegerParameter;
  42 import net.pterodactylus.util.database.Parameter.StringParameter;
  43 import net.pterodactylus.util.database.Query;
  44 import net.pterodactylus.util.database.Query.Type;
  45 import net.pterodactylus.util.database.ResultProcessor;
  46 import net.pterodactylus.util.database.ValueField;
  47 import net.pterodactylus.util.database.ValueFieldWhereClause;
  48
  49 /**
  50  * Interface between the database and the application.
  51  *
  52  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  53  */
  54 public class DataManager {
  55
  56         /** The artist object creator. */
  57         @SuppressWarnings("synthetic-access")
  58         private final ObjectCreator<Artist> artistCreator = new ArtistCreator();
  59
  60         /** The group object creator. */
  61         @SuppressWarnings("synthetic-access")
  62         private final ObjectCreator<Group> groupCreator = new GroupCreator();
  63
  64         /** The track object creator. */
  65         @SuppressWarnings("synthetic-access")
  66         private final ObjectCreator<Track> trackCreator = new TrackCreator();
  67
  68         /** The track object creator. */
  69         @SuppressWarnings("synthetic-access")
  70         private final ObjectCreator<TrackDerivative> trackDerivativeCreator = new TrackDerivativeCreator();
  71
  72         /** The style object creator. */
  73         @SuppressWarnings("synthetic-access")
  74         private final ObjectCreator<Style> styleCreator = new StyleCreator();
  75
  76         /** The {@link User} object creator. */
  77         @SuppressWarnings("synthetic-access")
  78         private final ObjectCreator<User> userCreator = new UserCreator();
  79
  80         /** The database. */
  81         private final Database database;
  82
  83         /**
  84          * Creates a new data manager.
  85          *
  86          * @param database
  87          *            The database to operate on
  88          */
  89         public DataManager(Database database) {
  90                 this.database = database;
  91         }
  92
  93         /**
  94          * Returns all artists.
  95          *
  96          * @return All artists
  97          * @throws DatabaseException
  98          *             if a database error occurs
  99          */
 100         public Collection<Artist> getAllArtists() throws DatabaseException {
 101                 Query query = new Query(Type.SELECT, "ARTISTS");
 102                 query.addField(new Field("ARTISTS.*"));
 103                 return loadArtistProperties(database.getMultiple(query, artistCreator));
 104         }
 105
 106         /**
 107          * Returns the artist with the given ID.
 108          *
 109          * @param id
 110          *            The ID of the artist
 111          * @return The artist with the given ID, or {@code null} if there is no
 112          *         artist with the given ID
 113          * @throws DatabaseException
 114          *             if a database error occurs
 115          */
 116         public Artist getArtistById(String id) throws DatabaseException {
 117                 Query query = new Query(Type.SELECT, "ARTISTS");
 118                 query.addField(new Field("ARTISTS.*"));
 119                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ARTISTS.ID", new StringParameter(id))));
 120                 return loadArtistProperties(database.getSingle(query, artistCreator));
 121         }
 122
 123         /**
 124          * Returns all artists that belong to the group with the given ID.
 125          *
 126          * @param groupId
 127          *            The ID of the group
 128          * @return All artists belonging to the given group
 129          * @throws DatabaseException
 130          *             if a database error occurs
 131          */
 132         public Collection<Artist> getArtistsByGroup(String groupId) throws DatabaseException {
 133                 Query query = new Query(Type.SELECT, "ARTISTS");
 134                 query.addField(new Field("ARTISTS.*"));
 135                 query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("ARTISTS.ID"), new Field("GROUP_ARTISTS.ARTIST")));
 136                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.GROUP_", new StringParameter(groupId))));
 137                 return loadArtistProperties(database.getMultiple(query, artistCreator));
 138         }
 139
 140         /**
 141          * Returns all artists involved in the track with the given ID.
 142          *
 143          * @param trackId
 144          *            The ID of the track
 145          * @return All artists involved in the track, in preferred order
 146          * @throws DatabaseException
 147          *             if a database error occurs
 148          */
 149         public List<Artist> getArtistsByTrack(String trackId) throws DatabaseException {
 150                 Query query = new Query(Type.SELECT, "ARTISTS");
 151                 query.addField(new Field("ARTISTS.*"));
 152                 query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACK_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
 153                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(trackId))));
 154                 query.addOrderField(new OrderField(new Field("TRACK_ARTISTS.DISPLAY_ORDER")));
 155                 return loadArtistProperties(database.getMultiple(query, artistCreator));
 156         }
 157
 158         /**
 159          * Creates a new artist with the given name.
 160          *
 161          * @param name
 162          *            The name of the artist
 163          * @return The created artist
 164          * @throws DatabaseException
 165          *             if a database error occurs
 166          */
 167         public Artist createArtist(String name) throws DatabaseException {
 168                 Query query = new Query(Type.INSERT, "ARTISTS");
 169                 String id = UUID.randomUUID().toString();
 170                 query.addValueField(new ValueField("ID", new StringParameter(id)));
 171                 query.addValueField(new ValueField("NAME", new StringParameter(name)));
 172                 database.insert(query);
 173                 return loadArtistProperties(getArtistById(id));
 174         }
 175
 176         /**
 177          * Saves the given artist.
 178          *
 179          * @param artist
 180          *            The artist to save
 181          * @throws DatabaseException
 182          *             if a database error occurs
 183          */
 184         public void saveArtist(Artist artist) throws DatabaseException {
 185                 Query query = new Query(Type.UPDATE, "ARTISTS");
 186                 query.addValueField(new ValueField("NAME", new StringParameter(artist.getName())));
 187                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ID", new StringParameter(artist.getId()))));
 188                 database.update(query);
 189                 saveArtistProperties(artist);
 190         }
 191
 192         /**
 193          * Saves the properties of the given artist.
 194          *
 195          * @param artist
 196          *            The artist whose properties to save
 197          * @throws DatabaseException
 198          *             if a database error occurs
 199          */
 200         public void saveArtistProperties(Artist artist) throws DatabaseException {
 201                 saveProperties(artist.getProperties(), "ARTIST_PROPERTIES", "ARTIST", artist.getId());
 202         }
 203
 204         /**
 205          * Saves the given properties to the given table for the given principal.
 206          *
 207          * @param properties
 208          *            The properties to save
 209          * @param table
 210          *            The table in which to save the properties
 211          * @param type
 212          *            The type of the principal (e. g. “ARTIST” or “TRACK”)
 213          * @param id
 214          *            The ID of the principial
 215          * @throws DatabaseException
 216          *             if a database error occurs
 217          */
 218         public void saveProperties(Properties properties, String table, String type, String id) throws DatabaseException {
 219                 if (!properties.isDirty()) {
 220                         return;
 221                 }
 222                 Query query = new Query(Type.DELETE, table);
 223                 query.addWhereClause(new ValueFieldWhereClause(new ValueField(type, new StringParameter(id))));
 224                 database.update(query);
 225                 for (Entry<String, String> property : properties) {
 226                         Query insertQuery = new Query(Type.INSERT, table);
 227                         insertQuery.addValueField(new ValueField(type, new StringParameter(id)));
 228                         insertQuery.addValueField(new ValueField("PROPERTY", new StringParameter(property.getKey())));
 229                         insertQuery.addValueField(new ValueField("VALUE", new StringParameter(property.getValue())));
 230                         database.insert(insertQuery);
 231                 }
 232                 properties.resetDirty();
 233         }
 234
 235         /**
 236          * Loads the properties for an artist.
 237          *
 238          * @param artist
 239          *            The artist to load the properties for
 240          * @return The artist
 241          * @throws DatabaseException
 242          *             if a database error occurs
 243          */
 244         public Artist loadArtistProperties(final Artist artist) throws DatabaseException {
 245                 return loadProperties(artist, "ARTIST_PROPERTIES", "ARTIST");
 246         }
 247
 248         /**
 249          * Loads the properties of all given artists.
 250          *
 251          * @param artists
 252          *            The artists to load the properties for
 253          * @return The list of artists
 254          * @throws DatabaseException
 255          *             if a database error occurs
 256          */
 257         public List<Artist> loadArtistProperties(List<Artist> artists) throws DatabaseException {
 258                 for (Artist artist : artists) {
 259                         loadArtistProperties(artist);
 260                 }
 261                 return artists;
 262         }
 263
 264         /**
 265          * Returns all remix artists involved in the track with the given ID.
 266          *
 267          * @param trackId
 268          *            The ID of the track
 269          * @return All remix artists involved in the track, in preferred order
 270          * @throws DatabaseException
 271          *             if a database error occurs
 272          */
 273         public List<Artist> getRemixArtistsByTrack(String trackId) throws DatabaseException {
 274                 Query query = new Query(Type.SELECT, "ARTISTS");
 275                 query.addField(new Field("ARTISTS.*"));
 276                 query.addJoin(new Join(JoinType.INNER, "TRACK_REMIX_ARTISTS", new Field("TRACK_REMIX_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
 277                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_REMIX_ARTISTS.TRACK", new StringParameter(trackId))));
 278                 query.addOrderField(new OrderField(new Field("TRACK_REMIX_ARTISTS.DISPLAY_ORDER")));
 279                 return database.getMultiple(query, artistCreator);
 280         }
 281
 282         /**
 283          * Returns all related tracks for the track with the given ID.
 284          *
 285          * @param trackId
 286          *            The ID of the tracks
 287          * @return A mapping from relationship to all tracks that match the relation
 288          * @throws DatabaseException
 289          *             if a database error occurs
 290          */
 291         public Map<Relationship, Collection<Track>> getRelatedTracksByTrack(String trackId) throws DatabaseException {
 292                 Query query = new Query(Type.SELECT, "TRACKS");
 293                 query.addField(new Field("TRACKS.*"));
 294                 query.addField(new Field("TRACK_RELATIONS.*"));
 295                 query.addJoin(new Join(JoinType.INNER, "TRACK_RELATIONS", new Field("TRACK_RELATIONS.TRACK"), new Field("TRACK_RELATIONS.RELATED_TRACK")));
 296                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_RELATIONS.TRACK", new StringParameter(trackId))));
 297                 final Map<Relationship, Collection<Track>> relatedTracks = new EnumMap<Relationship, Collection<Track>>(Relationship.class);
 298                 database.process(query, new ResultProcessor() {
 299
 300                         @Override
 301                         @SuppressWarnings("synthetic-access")
 302                         public void processResult(ResultSet resultSet) throws SQLException {
 303                                 Track track = trackCreator.createObject(resultSet);
 304                                 Relationship relationship = Relationship.valueOf(resultSet.getString("TRACK_RELATIONS.RELATIONSHIP"));
 305                                 if (!relatedTracks.containsKey(relationship)) {
 306                                         relatedTracks.put(relationship, new HashSet<Track>());
 307                                 }
 308                                 relatedTracks.get(relationship).add(track);
 309                         }
 310                 });
 311                 return relatedTracks;
 312         }
 313
 314         /**
 315          * Returns the track with the given ID.
 316          *
 317          * @param id
 318          *            The ID of the track
 319          * @return The track with the given ID, or {@code null} if there is no such
 320          *         track
 321          * @throws DatabaseException
 322          *             if a database error occurs
 323          */
 324         public Track getTrackById(String id) throws DatabaseException {
 325                 Query query = new Query(Type.SELECT, "TRACKS");
 326                 query.addField(new Field("TRACKS.*"));
 327                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACKS.ID", new StringParameter(id))));
 328                 return loadTrackProperties(database.getSingle(query, trackCreator));
 329         }
 330
 331         /**
 332          * Returns all tracks by the artist with the given ID.
 333          *
 334          * @param artistId
 335          *            The ID of the artist
 336          * @return All tracks by the given artist
 337          * @throws DatabaseException
 338          *             if a database error occurs
 339          */
 340         public Collection<Track> getTracksByArtist(String artistId) throws DatabaseException {
 341                 Query query = new Query(Type.SELECT, "TRACKS");
 342                 query.addField(new Field("TRACKS.*"));
 343                 query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACKS.ID"), new Field("TRACK_ARTISTS.TRACK")));
 344                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.ARTIST", new StringParameter(artistId))));
 345                 return loadTrackProperties(database.getMultiple(query, trackCreator));
 346         }
 347
 348         /**
 349          * Loads the properties for the given track.
 350          *
 351          * @param track
 352          *            The track for which to load the properties
 353          * @return The track with the properties loaded
 354          * @throws DatabaseException
 355          *             if a database error occurs
 356          */
 357         public Track loadTrackProperties(Track track) throws DatabaseException {
 358                 return loadProperties(track, "TRACK_PROPERTIES", "TRACK");
 359         }
 360
 361         /**
 362          * Loads the properties for the given tracks.
 363          *
 364          * @param tracks
 365          *            The tracks for which to load the properties
 366          * @return The tracks with the properties loaded
 367          * @throws DatabaseException
 368          *             if a database error occurs
 369          */
 370         public List<Track> loadTrackProperties(List<Track> tracks) throws DatabaseException {
 371                 for (Track track : tracks) {
 372                         loadTrackProperties(track);
 373                 }
 374                 return tracks;
 375         }
 376
 377         /**
 378          * Creates a new track with the given name.
 379          *
 380          * @param name
 381          *            The name of the track
 382          * @return The created track
 383          * @throws DatabaseException
 384          *             if a database error occurs
 385          */
 386         public Track createTrack(String name) throws DatabaseException {
 387                 Query query = new Query(Type.INSERT, "TRACKS");
 388                 String id = UUID.randomUUID().toString();
 389                 query.addValueField(new ValueField("ID", new StringParameter(id)));
 390                 query.addValueField(new ValueField("NAME", new StringParameter(name)));
 391                 database.insert(query);
 392                 return getTrackById(id);
 393         }
 394
 395         /**
 396          * Saves the given track. This also saves all relationships of the track.
 397          *
 398          * @param track
 399          *            The track to save
 400          * @throws DatabaseException
 401          *             if a database error occurs
 402          */
 403         public void saveTrack(Track track) throws DatabaseException {
 404                 Query query = new Query(Type.UPDATE, "TRACKS");
 405                 query.addValueField(new ValueField("TRACKS.NAME", new StringParameter(track.getName())));
 406                 query.addValueField(new ValueField("TRACKS.REMIX", new StringParameter(track.getRemix())));
 407                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACKS.ID", new StringParameter(track.getId()))));
 408                 database.update(query);
 409                 /* store artist information. */
 410                 track.getArtists(); /* prefetch artists. */
 411                 query = new Query(Type.DELETE, "TRACK_ARTISTS");
 412                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(track.getId()))));
 413                 database.update(query);
 414                 for (int index = 0; index < track.getArtists().size(); ++index) {
 415                         query = new Query(Type.INSERT, "TRACK_ARTISTS");
 416                         query.addValueField(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(track.getId())));
 417                         query.addValueField(new ValueField("TRACK_ARTISTS.ARTIST", new StringParameter(track.getArtists().get(index).getId())));
 418                         query.addValueField(new ValueField("TRACK_ARTISTS.DISPLAY_ORDER", new IntegerParameter(index + 1)));
 419                         database.insert(query);
 420                 }
 421                 /* store properties. */
 422                 saveProperties(track.getProperties(), "TRACK_PROPERTIES", "TRACK", track.getId());
 423         }
 424
 425         /**
 426          * Returns the derivative with the given ID.
 427          *
 428          * @param id
 429          *            The ID of the derivatives to load
 430          * @return The derivative with the given ID
 431          * @throws DatabaseException
 432          *             if a database error occurs
 433          */
 434         public TrackDerivative getTrackDerivativeById(String id) throws DatabaseException {
 435                 Query query = new Query(Type.SELECT, "TRACK_DERIVATIVES");
 436                 query.addField(new Field("TRACK_DERIVATIVES.*"));
 437                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_DERIVATIVES.ID", new StringParameter(id))));
 438                 return loadTrackDerivativeProperties(database.getSingle(query, trackDerivativeCreator));
 439         }
 440
 441         /**
 442          * Returns the derivatives for the given track.
 443          *
 444          * @param trackId
 445          *            The track ID to get the derivatives for
 446          * @return The derivatives for the given track
 447          * @throws DatabaseException
 448          *             if a database error occurs
 449          */
 450         public Collection<TrackDerivative> getTrackDerivativesByTrack(String trackId) throws DatabaseException {
 451                 Query query = new Query(Type.SELECT, "TRACK_DERIVATIVES");
 452                 query.addField(new Field("TRACK_DERIVATIVES.*"));
 453                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_DERIVATIVES.TRACK", new StringParameter(trackId))));
 454                 return loadTrackDerivativeProperties(database.getMultiple(query, trackDerivativeCreator));
 455         }
 456
 457         /**
 458          * Creates a new derivative for the given track.
 459          *
 460          * @param track
 461          *            The track to create the derivative for
 462          * @return The created derivative
 463          * @throws DatabaseException
 464          *             if a database error occurs
 465          */
 466         public TrackDerivative createTrackDerivative(Track track) throws DatabaseException {
 467                 Query query = new Query(Type.INSERT, "TRACK_DERIVATIVES");
 468                 String id = UUID.randomUUID().toString();
 469                 query.addValueField(new ValueField("TRACK_DERIVATIVES.ID", new StringParameter(id)));
 470                 query.addValueField(new ValueField("TRACK_DERIVATIVES.TRACK", new StringParameter(track.getId())));
 471                 database.insert(query);
 472                 return getTrackDerivativeById(id);
 473         }
 474
 475         /**
 476          * Loads the properties for the given track derivative.
 477          *
 478          * @param trackDerivative
 479          *            The track derivative to load the properties for
 480          * @return The track derivative with its properties loaded
 481          * @throws DatabaseException
 482          *             if a database error occurs
 483          */
 484         public TrackDerivative loadTrackDerivativeProperties(TrackDerivative trackDerivative) throws DatabaseException {
 485                 return loadProperties(trackDerivative, "TRACK_DERIVATIVE_PROPERTIES", "TRACK_DERIVATIVE");
 486         }
 487
 488         /**
 489          * Loads the properties for the given track derivatives.
 490          *
 491          * @param trackDerivatives
 492          *            The track derivatives to load the properties for
 493          * @return The track derivatives with their properties loaded
 494          * @throws DatabaseException
 495          *             if a database error occurs
 496          */
 497         public List<TrackDerivative> loadTrackDerivativeProperties(List<TrackDerivative> trackDerivatives) throws DatabaseException {
 498                 for (TrackDerivative trackDerivative : trackDerivatives) {
 499                         loadTrackDerivativeProperties(trackDerivative);
 500                 }
 501                 return trackDerivatives;
 502         }
 503
 504         /**
 505          * Returns all groups the artist with the given ID belongs to.
 506          *
 507          * @param artistId
 508          *            The ID of the artist
 509          * @return All groups the artist belongs to
 510          * @throws DatabaseException
 511          *             if a database error occurs
 512          */
 513         public Collection<Group> getGroupsByArtist(String artistId) throws DatabaseException {
 514                 Query query = new Query(Type.SELECT, "GROUPS");
 515                 query.addField(new Field("GROUPS.*"));
 516                 query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("GROUPS.ID"), new Field("GROUP_ARTISTS.GROUP_")));
 517                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.ARTIST", new StringParameter(artistId))));
 518                 return database.getMultiple(query, groupCreator);
 519         }
 520
 521         /**
 522          * Returns all styles for the track with the given ID.
 523          *
 524          * @param trackId
 525          *            The ID of the track
 526          * @return All styles for the given track
 527          * @throws DatabaseException
 528          *             if a database error occurs
 529          */
 530         public Collection<Style> getStylesByTrack(String trackId) throws DatabaseException {
 531                 Query query = new Query(Type.SELECT, "STYLES");
 532                 query.addField(new Field("STYLES.*"));
 533                 query.addJoin(new Join(JoinType.INNER, "TRACK_STYLES", new Field("STYLES.ID"), new Field("TRACK_STYLES.STYLE")));
 534                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_STYLES.TRACK", new StringParameter(trackId))));
 535                 return database.getMultiple(query, styleCreator);
 536         }
 537
 538         /**
 539          * Returns the user with the given name.
 540          *
 541          * @param username
 542          *            The name of the user
 543          * @return The user, or {@code null} if the user does not exist
 544          * @throws DatabaseException
 545          *             if a database error occurs
 546          */
 547         public User getUserByName(String username) throws DatabaseException {
 548                 Query query = new Query(Type.SELECT, "USERS");
 549                 query.addField(new Field("USERS.*"));
 550                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USERS.NAME", new StringParameter(username))));
 551                 return database.getSingle(query, userCreator);
 552         }
 553
 554         /**
 555          * Returns the user connected with the given OpenID.
 556          *
 557          * @param openId
 558          *            The OpenID to find the user for
 559          * @return The user connected with the given OpenID, or {@code null} if
 560          *         there is no such user
 561          * @throws DatabaseException
 562          *             if a database error occurs
 563          */
 564         public User getUserByOpenId(String openId) throws DatabaseException {
 565                 Query query = new Query(Type.SELECT, "USERS");
 566                 query.addField(new Field("USERS.*"));
 567                 query.addJoin(new Join(JoinType.INNER, "USER_OPENIDS", new Field("USER_OPENIDS.USER"), new Field("USERS.ID")));
 568                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USER_OPENIDS.OPENID", new StringParameter(openId))));
 569                 return database.getSingle(query, userCreator);
 570         }
 571
 572         /**
 573          * Returns all OpenIDs connected with the user with the given ID.
 574          *
 575          * @param userId
 576          *            The ID of the user
 577          * @return All OpenIDs connected with the given user
 578          * @throws DatabaseException
 579          *             if a database error occurs
 580          */
 581         public Collection<String> getOpenIdsByUser(String userId) throws DatabaseException {
 582                 Query query = new Query(Type.SELECT, "USER_OPENIDS");
 583                 query.addField(new Field("USER_OPENIDS.*"));
 584                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USER_OPENIDS.USER", new StringParameter(userId))));
 585                 return database.getMultiple(query, new StringCreator("USER_OPENIDS.OPENID"));
 586         }
 587
 588         //
 589         // PRIVATE METHODS
 590         //
 591
 592         /**
 593          * Loads the properties for the given object.
 594          *
 595          * @param <T>
 596          *            The type of the object
 597          * @param object
 598          *            The object
 599          * @param table
 600          *            The table to load the properties from
 601          * @param type
 602          *            The type of the object (“ARTIST,” “TRACK,” etc.)
 603          * @return The object with its properties loaded
 604          * @throws DatabaseException
 605          *             if a database error occurs
 606          */
 607         private <T extends Base> T loadProperties(final T object, final String table, String type) throws DatabaseException {
 608                 Query query = new Query(Type.SELECT, table);
 609                 query.addField(new Field(table + ".PROPERTY"));
 610                 query.addField(new Field(table + ".VALUE"));
 611                 query.addWhereClause(new ValueFieldWhereClause(new ValueField(type, new StringParameter(object.getId()))));
 612                 database.process(query, new ResultProcessor() {
 613
 614                         @Override
 615                         public void processResult(ResultSet resultSet) throws SQLException {
 616                                 if (resultSet.isFirst()) {
 617                                         object.getProperties().removeAll();
 618                                 }
 619                                 object.getProperties().set(resultSet.getString(table + ".PROPERTY"), resultSet.getString(table + ".VALUE"));
 620                         }
 621
 622                 });
 623                 return object;
 624         }
 625
 626         /**
 627          * {@link Artist} implementation that retrieves some attributes (such as
 628          * {@link #getGroups()}, and {@link #getTracks()}) from the
 629          * {@link DataManager} on demand.
 630          *
 631          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 632          */
 633         private class LazyArtist extends DefaultArtist {
 634
 635                 /** Memoizer for the tracks by this artist. */
 636                 private final Memoizer<Void> tracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
 637
 638                         @Override
 639                         public Void call() throws DatabaseException {
 640                                 if (!hasValue("tracks")) {
 641                                         getValue("tracks", Collection.class).set(getTracksByArtist(getId()));
 642                                 }
 643                                 return null;
 644                         }
 645                 });
 646
 647                 /** Memoizer for the groups of this artist. */
 648                 private final Memoizer<Void> groupsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 649
 650                         @Override
 651                         public Void call() throws Exception {
 652                                 if (!hasValue("groups")) {
 653                                         getValue("groups", Collection.class).set(getGroupsByArtist(getId()));
 654                                 }
 655                                 return null;
 656                         }
 657
 658                 });
 659
 660                 /**
 661                  * Creates a new lazy artist.
 662                  *
 663                  * @param id
 664                  *            The ID of the artist
 665                  */
 666                 public LazyArtist(String id) {
 667                         super(id);
 668                 }
 669
 670                 //
 671                 // DEFAULTARTIST METHODS
 672                 //
 673
 674                 /**
 675                  * {@inheritDoc}
 676                  */
 677                 @Override
 678                 public Collection<Group> getGroups() {
 679                         groupsMemoizer.get();
 680                         return super.getGroups();
 681                 }
 682
 683                 /**
 684                  * {@inheritDoc}
 685                  */
 686                 @Override
 687                 public Collection<Track> getTracks() {
 688                         tracksMemoizer.get();
 689                         return super.getTracks();
 690                 }
 691
 692         }
 693
 694         /**
 695          * {@link ObjectCreator} implementation that can create {@link Artist}
 696          * objects. This specific class actually creates {@link LazyArtist}
 697          * instances.
 698          *
 699          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 700          */
 701         private class ArtistCreator implements ObjectCreator<Artist> {
 702
 703                 /**
 704                  * {@inheritDoc}
 705                  */
 706                 @Override
 707                 public Artist createObject(ResultSet resultSet) throws SQLException {
 708                         return new LazyArtist(resultSet.getString("ARTISTS.ID")).setName(resultSet.getString("ARTISTS.NAME"));
 709                 }
 710
 711         }
 712
 713         /**
 714          * {@link Group} implementation that retrieves some attributes (such as
 715          * {@link #getArtists()}) from the {@link DataManager} on demand.
 716          *
 717          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 718          */
 719         private class LazyGroup extends DefaultGroup {
 720
 721                 /** Memoizer for the artist. */
 722                 private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 723
 724                         @Override
 725                         public Void call() throws Exception {
 726                                 if (!hasValue("artists")) {
 727                                         getValue("artists", Collection.class).set(getArtistsByGroup(getId()));
 728                                 }
 729                                 return null;
 730                         }
 731
 732                 });
 733
 734                 /**
 735                  * Creates a new lazy group.
 736                  *
 737                  * @param id
 738                  *            The ID of the group
 739                  */
 740                 public LazyGroup(String id) {
 741                         super(id);
 742                 }
 743
 744                 //
 745                 // DEFAULTGROUP METHODS
 746                 //
 747
 748                 /**
 749                  * {@inheritDoc}
 750                  */
 751                 @Override
 752                 public Collection<Artist> getArtists() {
 753                         artistsMemoizer.get();
 754                         return super.getArtists();
 755                 }
 756
 757         }
 758
 759         /**
 760          * {@link ObjectCreator} implementation that can create {@link Group}
 761          * objects. This specific implementation creates {@link LazyGroup}
 762          * instances.
 763          *
 764          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 765          */
 766         private class GroupCreator implements ObjectCreator<Group> {
 767
 768                 /**
 769                  * {@inheritDoc}
 770                  */
 771                 @Override
 772                 public Group createObject(ResultSet resultSet) throws SQLException {
 773                         return new LazyGroup(resultSet.getString("GROUPS.ID")).setName(resultSet.getString("GROUPS.NAME")).setUrl(resultSet.getString("GROUPS.URL"));
 774                 }
 775
 776         }
 777
 778         /**
 779          * {@link Track} implementation that retrieves some attributes (such as
 780          * {@link #getArtists()}, and {@link #getStyles()}) from the
 781          * {@link DataManager} on demand.
 782          *
 783          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 784          */
 785         private class LazyTrack extends DefaultTrack {
 786
 787                 /** Memoizer for the artists. */
 788                 private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 789
 790                         @Override
 791                         public Void call() throws Exception {
 792                                 if (!hasValue("artists")) {
 793                                         getValue("artists", List.class).set(getArtistsByTrack(getId()));
 794                                 }
 795                                 return null;
 796                         }
 797
 798                 });
 799
 800                 /** Memoizer for the styles. */
 801                 private final Memoizer<Void> stylesMemoizer = new Memoizer<Void>(new Callable<Void>() {
 802
 803                         @Override
 804                         public Void call() throws Exception {
 805                                 if (!hasValue("styles")) {
 806                                         getValue("styles", Collection.class).set(getStylesByTrack(getId()));
 807                                 }
 808                                 return null;
 809                         }
 810
 811                 });
 812
 813                 /** Memoizer for the remix artists. */
 814                 private final Memoizer<Void> remixArtistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 815
 816                         @Override
 817                         public Void call() throws Exception {
 818                                 if (!hasValue("remixArtists")) {
 819                                         getValue("remixArtists", List.class).set(getRemixArtistsByTrack(getId()));
 820                                 }
 821                                 return null;
 822                         }
 823
 824                 });
 825
 826                 /** Memoizer for the track derivatives. */
 827                 private final Memoizer<Void> derivativesMemoizer = new Memoizer<Void>(new Callable<Void>() {
 828
 829                         @Override
 830                         public Void call() throws Exception {
 831                                 if (!hasValue("derivatives")) {
 832                                         getValue("derivatives", Collection.class).set(getTrackDerivativesByTrack(getId()));
 833                                 }
 834                                 return null;
 835                         }
 836
 837                 });
 838
 839                 /** Memoizer for the related tracks. */
 840                 private final Memoizer<Void> relatedTracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
 841
 842                         @Override
 843                         public Void call() throws Exception {
 844                                 if (!hasValue("relatedTracks")) {
 845                                         getValue("relatedTracks", Map.class).set(getRelatedTracksByTrack(getId()));
 846                                 }
 847                                 return null;
 848                         }
 849
 850                 });
 851
 852                 /**
 853                  * Creates a new track.
 854                  *
 855                  * @param id
 856                  *            The ID of the track
 857                  */
 858                 public LazyTrack(String id) {
 859                         super(id);
 860                 }
 861
 862                 //
 863                 // DEFAULTTRACK METHODS
 864                 //
 865
 866                 /**
 867                  * {@inheritDoc}
 868                  */
 869                 @Override
 870                 public List<Artist> getArtists() {
 871                         artistsMemoizer.get();
 872                         return super.getArtists();
 873                 }
 874
 875                 /**
 876                  * {@inheritDoc}
 877                  */
 878                 @Override
 879                 public Collection<Style> getStyles() {
 880                         stylesMemoizer.get();
 881                         return super.getStyles();
 882                 }
 883
 884                 /**
 885                  * {@inheritDoc}
 886                  */
 887                 @Override
 888                 public List<Artist> getRemixArtists() {
 889                         remixArtistsMemoizer.get();
 890                         return super.getRemixArtists();
 891                 }
 892
 893                 /**
 894                  * {@inheritDoc}
 895                  */
 896                 @Override
 897                 public Collection<TrackDerivative> getDerivatives() {
 898                         derivativesMemoizer.get();
 899                         return super.getDerivatives();
 900                 }
 901
 902                 /**
 903                  * {@inheritDoc}
 904                  */
 905                 @Override
 906                 public Map<Relationship, Collection<Track>> getRelatedTracks() {
 907                         relatedTracksMemoizer.get();
 908                         return super.getRelatedTracks();
 909                 }
 910
 911         }
 912
 913         /**
 914          * {@link ObjectCreator} implementation that can create {@link Track}
 915          * objects. This specific implementation creates {@link LazyTrack}
 916          * instances.
 917          *
 918          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 919          */
 920         private class TrackCreator implements ObjectCreator<Track> {
 921
 922                 /**
 923                  * {@inheritDoc}
 924                  */
 925                 @Override
 926                 public Track createObject(ResultSet resultSet) throws SQLException {
 927                         return new LazyTrack(resultSet.getString("TRACKS.ID")).setName(resultSet.getString("TRACKS.NAME")).setRemix(resultSet.getString("TRACKS.REMIX"));
 928                 }
 929
 930         }
 931
 932         /**
 933          * {@link ObjectCreator} implementation that can create
 934          * {@link TrackDerivative} objects.
 935          *
 936          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 937          */
 938         private class TrackDerivativeCreator implements ObjectCreator<TrackDerivative> {
 939
 940                 /**
 941                  * {@inheritDoc}
 942                  */
 943                 @Override
 944                 public TrackDerivative createObject(ResultSet resultSet) throws SQLException {
 945                         return new DefaultTrackDerivative(resultSet.getString("TRACK_DERIVATIVES.ID"));
 946                 }
 947
 948         }
 949
 950         /**
 951          * {@link ObjectCreator} implementation that can create {@link Style}
 952          * objects.
 953          *
 954          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 955          */
 956         private class StyleCreator implements ObjectCreator<Style> {
 957
 958                 /**
 959                  * {@inheritDoc}
 960                  */
 961                 @Override
 962                 public Style createObject(ResultSet resultSet) throws SQLException {
 963                         return new DefaultStyle(resultSet.getString("STYLES.ID")).setName(resultSet.getString("STYLES.NAME"));
 964                 }
 965
 966         }
 967
 968         /**
 969          * {@link User} implementation that retrieves some attributes (such as
 970          * {@link #getOpenIds()}) from the {@link DataManager} on demand.
 971          *
 972          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 973          */
 974         private class LazyUser extends DefaultUser {
 975
 976                 /** Memoizer for a user’s OpenIDs. */
 977                 private final Memoizer<Void> openIdMemoizer = new Memoizer<Void>(new Callable<Void>() {
 978
 979                         @Override
 980                         public Void call() throws Exception {
 981                                 if (!hasValue("openIds")) {
 982                                         getValue("openIds", Collection.class).set(getOpenIdsByUser(getId()));
 983                                 }
 984                                 return null;
 985                         }
 986                 });
 987
 988                 /**
 989                  * Creates a new user.
 990                  *
 991                  * @param id
 992                  *            The ID of the user
 993                  */
 994                 public LazyUser(String id) {
 995                         super(id);
 996                 }
 997
 998                 /**
 999                  * {@inheritDoc}
1000                  */
1001                 @Override
1002                 public Collection<String> getOpenIds() {
1003                         openIdMemoizer.get();
1004                         return super.getOpenIds();
1005                 }
1006
1007         }
1008
1009         /**
1010          * {@link ObjectCreator} implementation that can create {@link User}
1011          * objects. This specific implementation creates {@link LazyUser} instances.
1012          *
1013          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1014          */
1015         private class UserCreator implements ObjectCreator<User> {
1016
1017                 /**
1018                  * {@inheritDoc}
1019                  */
1020                 @Override
1021                 public User createObject(ResultSet resultSet) throws SQLException {
1022                         return new LazyUser(resultSet.getString("USERS.ID")).setName(resultSet.getString("USERS.NAME")).setPasswordHash(resultSet.getString("USERS.PASSWORD")).setLevel(resultSet.getInt("USERS.LEVEL"));
1023                 }
1024
1025         }
1026
1027 }