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 party object creator. */
  77         @SuppressWarnings("synthetic-access")
  78         private final ObjectCreator<Party> partyCreator = new PartyCreator();
  79
  80         /** The {@link User} object creator. */
  81         @SuppressWarnings("synthetic-access")
  82         private final ObjectCreator<User> userCreator = new UserCreator();
  83
  84         /** The database. */
  85         private final Database database;
  86
  87         /**
  88          * Creates a new data manager.
  89          *
  90          * @param database
  91          *            The database to operate on
  92          */
  93         public DataManager(Database database) {
  94                 this.database = database;
  95         }
  96
  97         /**
  98          * Returns all artists.
  99          *
 100          * @return All artists
 101          * @throws DatabaseException
 102          *             if a database error occurs
 103          */
 104         public Collection<Artist> getAllArtists() throws DatabaseException {
 105                 Query query = new Query(Type.SELECT, "ARTISTS");
 106                 query.addField(new Field("ARTISTS.*"));
 107                 return loadArtistProperties(database.getMultiple(query, artistCreator));
 108         }
 109
 110         /**
 111          * Returns the artist with the given ID.
 112          *
 113          * @param id
 114          *            The ID of the artist
 115          * @return The artist with the given ID, or {@code null} if there is no
 116          *         artist with the given ID
 117          * @throws DatabaseException
 118          *             if a database error occurs
 119          */
 120         public Artist getArtistById(String id) throws DatabaseException {
 121                 Query query = new Query(Type.SELECT, "ARTISTS");
 122                 query.addField(new Field("ARTISTS.*"));
 123                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ARTISTS.ID", new StringParameter(id))));
 124                 return loadArtistProperties(database.getSingle(query, artistCreator));
 125         }
 126
 127         /**
 128          * Returns all artists that belong to the group with the given ID.
 129          *
 130          * @param groupId
 131          *            The ID of the group
 132          * @return All artists belonging to the given group
 133          * @throws DatabaseException
 134          *             if a database error occurs
 135          */
 136         public Collection<Artist> getArtistsByGroup(String groupId) throws DatabaseException {
 137                 Query query = new Query(Type.SELECT, "ARTISTS");
 138                 query.addField(new Field("ARTISTS.*"));
 139                 query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("ARTISTS.ID"), new Field("GROUP_ARTISTS.ARTIST")));
 140                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.GROUP_", new StringParameter(groupId))));
 141                 return loadArtistProperties(database.getMultiple(query, artistCreator));
 142         }
 143
 144         /**
 145          * Returns all artists involved in the track with the given ID.
 146          *
 147          * @param trackId
 148          *            The ID of the track
 149          * @return All artists involved in the track, in preferred order
 150          * @throws DatabaseException
 151          *             if a database error occurs
 152          */
 153         public List<Artist> getArtistsByTrack(String trackId) throws DatabaseException {
 154                 Query query = new Query(Type.SELECT, "ARTISTS");
 155                 query.addField(new Field("ARTISTS.*"));
 156                 query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACK_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
 157                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(trackId))));
 158                 query.addOrderField(new OrderField(new Field("TRACK_ARTISTS.DISPLAY_ORDER")));
 159                 return loadArtistProperties(database.getMultiple(query, artistCreator));
 160         }
 161
 162         /**
 163          * Creates a new artist with the given name.
 164          *
 165          * @param name
 166          *            The name of the artist
 167          * @return The created artist
 168          * @throws DatabaseException
 169          *             if a database error occurs
 170          */
 171         public Artist createArtist(String name) throws DatabaseException {
 172                 Query query = new Query(Type.INSERT, "ARTISTS");
 173                 String id = UUID.randomUUID().toString();
 174                 query.addValueField(new ValueField("ID", new StringParameter(id)));
 175                 query.addValueField(new ValueField("NAME", new StringParameter(name)));
 176                 database.insert(query);
 177                 return loadArtistProperties(getArtistById(id));
 178         }
 179
 180         /**
 181          * Saves the given artist.
 182          *
 183          * @param artist
 184          *            The artist to save
 185          * @throws DatabaseException
 186          *             if a database error occurs
 187          */
 188         public void saveArtist(Artist artist) throws DatabaseException {
 189                 Query query = new Query(Type.UPDATE, "ARTISTS");
 190                 query.addValueField(new ValueField("NAME", new StringParameter(artist.getName())));
 191                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ID", new StringParameter(artist.getId()))));
 192                 database.update(query);
 193
 194                 /* save groups. */
 195                 Collection<Group> groups = artist.getGroups();
 196                 query = new Query(Type.DELETE, "GROUP_ARTISTS");
 197                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.ARTIST", new StringParameter(artist.getId()))));
 198                 database.update(query);
 199                 for (Group group : groups) {
 200                         query = new Query(Type.INSERT, "GROUP_ARTISTS");
 201                         query.addValueField(new ValueField("GROUP_", new StringParameter(group.getId())));
 202                         query.addValueField(new ValueField("ARTIST", new StringParameter(artist.getId())));
 203                         database.insert(query);
 204                 }
 205
 206                 /* save properties. */
 207                 saveArtistProperties(artist);
 208         }
 209
 210         /**
 211          * Saves the properties of the given artist.
 212          *
 213          * @param artist
 214          *            The artist whose properties to save
 215          * @throws DatabaseException
 216          *             if a database error occurs
 217          */
 218         public void saveArtistProperties(Artist artist) throws DatabaseException {
 219                 saveProperties(artist.getProperties(), "ARTIST_PROPERTIES", "ARTIST", artist.getId());
 220         }
 221
 222         /**
 223          * Saves the given properties to the given table for the given principal.
 224          *
 225          * @param properties
 226          *            The properties to save
 227          * @param table
 228          *            The table in which to save the properties
 229          * @param type
 230          *            The type of the principal (e. g. “ARTIST” or “TRACK”)
 231          * @param id
 232          *            The ID of the principial
 233          * @throws DatabaseException
 234          *             if a database error occurs
 235          */
 236         public void saveProperties(Properties properties, String table, String type, String id) throws DatabaseException {
 237                 if (!properties.isDirty()) {
 238                         return;
 239                 }
 240                 Query query = new Query(Type.DELETE, table);
 241                 query.addWhereClause(new ValueFieldWhereClause(new ValueField(type, new StringParameter(id))));
 242                 database.update(query);
 243                 for (Entry<String, String> property : properties) {
 244                         Query insertQuery = new Query(Type.INSERT, table);
 245                         insertQuery.addValueField(new ValueField(type, new StringParameter(id)));
 246                         insertQuery.addValueField(new ValueField("PROPERTY", new StringParameter(property.getKey())));
 247                         insertQuery.addValueField(new ValueField("VALUE", new StringParameter(property.getValue())));
 248                         database.insert(insertQuery);
 249                 }
 250                 properties.resetDirty();
 251         }
 252
 253         /**
 254          * Loads the properties for an artist.
 255          *
 256          * @param artist
 257          *            The artist to load the properties for
 258          * @return The artist
 259          * @throws DatabaseException
 260          *             if a database error occurs
 261          */
 262         public Artist loadArtistProperties(final Artist artist) throws DatabaseException {
 263                 return loadProperties(artist, "ARTIST_PROPERTIES", "ARTIST");
 264         }
 265
 266         /**
 267          * Loads the properties of all given artists.
 268          *
 269          * @param artists
 270          *            The artists to load the properties for
 271          * @return The list of artists
 272          * @throws DatabaseException
 273          *             if a database error occurs
 274          */
 275         public List<Artist> loadArtistProperties(List<Artist> artists) throws DatabaseException {
 276                 for (Artist artist : artists) {
 277                         loadArtistProperties(artist);
 278                 }
 279                 return artists;
 280         }
 281
 282         /**
 283          * Returns all remix artists involved in the track with the given ID.
 284          *
 285          * @param trackId
 286          *            The ID of the track
 287          * @return All remix artists involved in the track, in preferred order
 288          * @throws DatabaseException
 289          *             if a database error occurs
 290          */
 291         public List<Artist> getRemixArtistsByTrack(String trackId) throws DatabaseException {
 292                 Query query = new Query(Type.SELECT, "ARTISTS");
 293                 query.addField(new Field("ARTISTS.*"));
 294                 query.addJoin(new Join(JoinType.INNER, "TRACK_REMIX_ARTISTS", new Field("TRACK_REMIX_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
 295                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_REMIX_ARTISTS.TRACK", new StringParameter(trackId))));
 296                 query.addOrderField(new OrderField(new Field("TRACK_REMIX_ARTISTS.DISPLAY_ORDER")));
 297                 return database.getMultiple(query, artistCreator);
 298         }
 299
 300         /**
 301          * Returns all related tracks for the track with the given ID.
 302          *
 303          * @param trackId
 304          *            The ID of the tracks
 305          * @return A mapping from relationship to all tracks that match the relation
 306          * @throws DatabaseException
 307          *             if a database error occurs
 308          */
 309         public Map<Relationship, Collection<Track>> getRelatedTracksByTrack(String trackId) throws DatabaseException {
 310                 Query query = new Query(Type.SELECT, "TRACKS");
 311                 query.addField(new Field("TRACKS.*"));
 312                 query.addField(new Field("TRACK_RELATIONS.*"));
 313                 query.addJoin(new Join(JoinType.INNER, "TRACK_RELATIONS", new Field("TRACK_RELATIONS.TRACK"), new Field("TRACK_RELATIONS.RELATED_TRACK")));
 314                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_RELATIONS.TRACK", new StringParameter(trackId))));
 315                 final Map<Relationship, Collection<Track>> relatedTracks = new EnumMap<Relationship, Collection<Track>>(Relationship.class);
 316                 database.process(query, new ResultProcessor() {
 317
 318                         @Override
 319                         @SuppressWarnings("synthetic-access")
 320                         public void processResult(ResultSet resultSet) throws SQLException {
 321                                 Track track = trackCreator.createObject(resultSet);
 322                                 Relationship relationship = Relationship.valueOf(resultSet.getString("TRACK_RELATIONS.RELATIONSHIP"));
 323                                 if (!relatedTracks.containsKey(relationship)) {
 324                                         relatedTracks.put(relationship, new HashSet<Track>());
 325                                 }
 326                                 relatedTracks.get(relationship).add(track);
 327                         }
 328                 });
 329                 return relatedTracks;
 330         }
 331
 332         /**
 333          * Returns the track with the given ID.
 334          *
 335          * @param id
 336          *            The ID of the track
 337          * @return The track with the given ID, or {@code null} if there is no such
 338          *         track
 339          * @throws DatabaseException
 340          *             if a database error occurs
 341          */
 342         public Track getTrackById(String id) throws DatabaseException {
 343                 Query query = new Query(Type.SELECT, "TRACKS");
 344                 query.addField(new Field("TRACKS.*"));
 345                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACKS.ID", new StringParameter(id))));
 346                 return loadTrackProperties(database.getSingle(query, trackCreator));
 347         }
 348
 349         /**
 350          * Returns the track that contains the derivative with the given ID.
 351          *
 352          * @param id
 353          *            The ID of the track derivative
 354          * @return The track the derivative belongs to, or {@code null} if there is
 355          *         no such track
 356          * @throws DatabaseException
 357          *             if a database error occurs
 358          */
 359         public Track getTrackByDerivativeId(String id) throws DatabaseException {
 360                 Query query = new Query(Type.SELECT, "TRACKS");
 361                 query.addField(new Field("TRACKS.*"));
 362                 query.addJoin(new Join(JoinType.INNER, "TRACK_DERIVATIVES", new Field("TRACK_DERIVATIVES.TRACK"), new Field("TRACKS.ID")));
 363                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_DERIVATIVES.ID", new StringParameter(id))));
 364                 return loadTrackProperties(database.getSingle(query, trackCreator));
 365         }
 366
 367         /**
 368          * Returns all tracks by the artist with the given ID.
 369          *
 370          * @param artistId
 371          *            The ID of the artist
 372          * @return All tracks by the given artist
 373          * @throws DatabaseException
 374          *             if a database error occurs
 375          */
 376         public Collection<Track> getTracksByArtist(String artistId) throws DatabaseException {
 377                 Query query = new Query(Type.SELECT, "TRACKS");
 378                 query.addField(new Field("TRACKS.*"));
 379                 query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACKS.ID"), new Field("TRACK_ARTISTS.TRACK")));
 380                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.ARTIST", new StringParameter(artistId))));
 381                 return loadTrackProperties(database.getMultiple(query, trackCreator));
 382         }
 383
 384         /**
 385          * Returns all tracks that were released at the party with the given ID.
 386          *
 387          * @param partyId
 388          *            The ID of the party
 389          * @return All tracks that were released at the given party
 390          * @throws DatabaseException
 391          *             if a database error occurs
 392          */
 393         public Collection<Track> getTracksByParty(String partyId) throws DatabaseException {
 394                 Query query = new Query(Type.SELECT, "TRACKS");
 395                 query.addField(new Field("TRACKS.*"));
 396                 query.addJoin(new Join(JoinType.INNER, "PARTY_TRACKS", new Field("PARTY_TRACKS.TRACK"), new Field("TRACKS.ID")));
 397                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("PARTY_TRACKS.PARTY", new StringParameter(partyId))));
 398                 return loadTrackProperties(database.getMultiple(query, trackCreator));
 399         }
 400
 401         /**
 402          * Loads the properties for the given track.
 403          *
 404          * @param track
 405          *            The track for which to load the properties
 406          * @return The track with the properties loaded
 407          * @throws DatabaseException
 408          *             if a database error occurs
 409          */
 410         public Track loadTrackProperties(Track track) throws DatabaseException {
 411                 return loadProperties(track, "TRACK_PROPERTIES", "TRACK");
 412         }
 413
 414         /**
 415          * Loads the properties for the given tracks.
 416          *
 417          * @param tracks
 418          *            The tracks for which to load the properties
 419          * @return The tracks with the properties loaded
 420          * @throws DatabaseException
 421          *             if a database error occurs
 422          */
 423         public List<Track> loadTrackProperties(List<Track> tracks) throws DatabaseException {
 424                 for (Track track : tracks) {
 425                         loadTrackProperties(track);
 426                 }
 427                 return tracks;
 428         }
 429
 430         /**
 431          * Creates a new track with the given name.
 432          *
 433          * @param name
 434          *            The name of the track
 435          * @return The created track
 436          * @throws DatabaseException
 437          *             if a database error occurs
 438          */
 439         public Track createTrack(String name) throws DatabaseException {
 440                 Query query = new Query(Type.INSERT, "TRACKS");
 441                 String id = UUID.randomUUID().toString();
 442                 query.addValueField(new ValueField("ID", new StringParameter(id)));
 443                 query.addValueField(new ValueField("NAME", new StringParameter(name)));
 444                 database.insert(query);
 445                 return getTrackById(id);
 446         }
 447
 448         /**
 449          * Saves the given track. This also saves all relationships of the track.
 450          *
 451          * @param track
 452          *            The track to save
 453          * @throws DatabaseException
 454          *             if a database error occurs
 455          */
 456         public void saveTrack(Track track) throws DatabaseException {
 457                 Query query = new Query(Type.UPDATE, "TRACKS");
 458                 query.addValueField(new ValueField("TRACKS.NAME", new StringParameter(track.getName())));
 459                 query.addValueField(new ValueField("TRACKS.REMIX", new StringParameter(track.getRemix())));
 460                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACKS.ID", new StringParameter(track.getId()))));
 461                 database.update(query);
 462                 /* store artist information. */
 463                 track.getArtists(); /* prefetch artists. */
 464                 query = new Query(Type.DELETE, "TRACK_ARTISTS");
 465                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(track.getId()))));
 466                 database.update(query);
 467                 for (int index = 0; index < track.getArtists().size(); ++index) {
 468                         query = new Query(Type.INSERT, "TRACK_ARTISTS");
 469                         query.addValueField(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(track.getId())));
 470                         query.addValueField(new ValueField("TRACK_ARTISTS.ARTIST", new StringParameter(track.getArtists().get(index).getId())));
 471                         query.addValueField(new ValueField("TRACK_ARTISTS.DISPLAY_ORDER", new IntegerParameter(index + 1)));
 472                         database.insert(query);
 473                 }
 474
 475                 /* store party links. */
 476                 Collection<Party> parties = track.getParties(); /* prefetch parties. */
 477                 query = new Query(Type.DELETE, "PARTY_TRACKS");
 478                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("PARTY_TRACKS.TRACK", new StringParameter(track.getId()))));
 479                 database.update(query);
 480                 for (Party party : parties) {
 481                         query = new Query(Type.INSERT, "PARTY_TRACKS");
 482                         query.addValueField(new ValueField("PARTY_TRACKS.TRACK", new StringParameter(track.getId())));
 483                         query.addValueField(new ValueField("PARTY_TRACKS.PARTY", new StringParameter(party.getId())));
 484                         database.insert(query);
 485                 }
 486
 487                 /* store properties. */
 488                 saveProperties(track.getProperties(), "TRACK_PROPERTIES", "TRACK", track.getId());
 489         }
 490
 491         /**
 492          * Returns the derivative with the given ID.
 493          *
 494          * @param id
 495          *            The ID of the derivatives to load
 496          * @return The derivative with the given ID
 497          * @throws DatabaseException
 498          *             if a database error occurs
 499          */
 500         public TrackDerivative getTrackDerivativeById(String id) throws DatabaseException {
 501                 Query query = new Query(Type.SELECT, "TRACK_DERIVATIVES");
 502                 query.addField(new Field("TRACK_DERIVATIVES.*"));
 503                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_DERIVATIVES.ID", new StringParameter(id))));
 504                 return loadTrackDerivativeProperties(database.getSingle(query, trackDerivativeCreator));
 505         }
 506
 507         /**
 508          * Returns the derivatives for the given track.
 509          *
 510          * @param trackId
 511          *            The track ID to get the derivatives for
 512          * @return The derivatives for the given track
 513          * @throws DatabaseException
 514          *             if a database error occurs
 515          */
 516         public Collection<TrackDerivative> getTrackDerivativesByTrack(String trackId) throws DatabaseException {
 517                 Query query = new Query(Type.SELECT, "TRACK_DERIVATIVES");
 518                 query.addField(new Field("TRACK_DERIVATIVES.*"));
 519                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_DERIVATIVES.TRACK", new StringParameter(trackId))));
 520                 return loadTrackDerivativeProperties(database.getMultiple(query, trackDerivativeCreator));
 521         }
 522
 523         /**
 524          * Creates a new derivative for the given track.
 525          *
 526          * @param track
 527          *            The track to create the derivative for
 528          * @return The created derivative
 529          * @throws DatabaseException
 530          *             if a database error occurs
 531          */
 532         public TrackDerivative createTrackDerivative(Track track) throws DatabaseException {
 533                 Query query = new Query(Type.INSERT, "TRACK_DERIVATIVES");
 534                 String id = UUID.randomUUID().toString();
 535                 query.addValueField(new ValueField("TRACK_DERIVATIVES.ID", new StringParameter(id)));
 536                 query.addValueField(new ValueField("TRACK_DERIVATIVES.TRACK", new StringParameter(track.getId())));
 537                 database.insert(query);
 538                 return getTrackDerivativeById(id);
 539         }
 540
 541         /**
 542          * Loads the properties for the given track derivative.
 543          *
 544          * @param trackDerivative
 545          *            The track derivative to load the properties for
 546          * @return The track derivative with its properties loaded
 547          * @throws DatabaseException
 548          *             if a database error occurs
 549          */
 550         public TrackDerivative loadTrackDerivativeProperties(TrackDerivative trackDerivative) throws DatabaseException {
 551                 return loadProperties(trackDerivative, "TRACK_DERIVATIVE_PROPERTIES", "TRACK_DERIVATIVE");
 552         }
 553
 554         /**
 555          * Loads the properties for the given track derivatives.
 556          *
 557          * @param trackDerivatives
 558          *            The track derivatives to load the properties for
 559          * @return The track derivatives with their properties loaded
 560          * @throws DatabaseException
 561          *             if a database error occurs
 562          */
 563         public List<TrackDerivative> loadTrackDerivativeProperties(List<TrackDerivative> trackDerivatives) throws DatabaseException {
 564                 for (TrackDerivative trackDerivative : trackDerivatives) {
 565                         loadTrackDerivativeProperties(trackDerivative);
 566                 }
 567                 return trackDerivatives;
 568         }
 569
 570         /**
 571          * Saves the given track derivative. As a track derivative does not have any
 572          * attributes of its own only its properties are saved.
 573          *
 574          * @param trackDerivative
 575          *            The track derivative to save
 576          * @throws DatabaseException
 577          *             if a database error occurs
 578          */
 579         public void saveTrackDerivate(TrackDerivative trackDerivative) throws DatabaseException {
 580                 saveProperties(trackDerivative.getProperties(), "TRACK_DERIVATIVE_PROPERTIES", "TRACK_DERIVATIVE", trackDerivative.getId());
 581         }
 582
 583         /**
 584          * Removes the given track derivative and all its properties from the
 585          * database.
 586          *
 587          * @param trackDerivative
 588          *            The track derivative to remove
 589          * @throws DatabaseException
 590          *             if a database error occurs
 591          */
 592         public void removeTrackDerivative(TrackDerivative trackDerivative) throws DatabaseException {
 593                 Query query = new Query(Type.DELETE, "TRACK_DERIVATIVES");
 594                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_DERIVATIVES.ID", new StringParameter(trackDerivative.getId()))));
 595                 database.update(query);
 596                 /* remove the properties. */
 597                 saveProperties(new Properties().set("dirty", "true").removeAll(), "TRACK_DERIVATIVE_PROPERTIES", "TRACK_DERIVATIVE", trackDerivative.getId());
 598         }
 599
 600         /**
 601          * Returns all groups.
 602          *
 603          * @return All groups
 604          * @throws DatabaseException
 605          *             if a database error occurs
 606          */
 607         public Collection<Group> getAllGroups() throws DatabaseException {
 608                 Query query = new Query(Type.SELECT, "GROUPS");
 609                 query.addField(new Field("GROUPS.*"));
 610                 return loadGroupProperties(database.getMultiple(query, groupCreator));
 611         }
 612
 613         /**
 614          * Returns the group with the given ID.
 615          *
 616          * @param groupId
 617          *            The ID of the group
 618          * @return The group with the given ID, or {@code null} if no such group
 619          *         exists
 620          * @throws DatabaseException
 621          *             if a database error occurs
 622          */
 623         public Group getGroupById(String groupId) throws DatabaseException {
 624                 Query query = new Query(Type.SELECT, "GROUPS");
 625                 query.addField(new Field("GROUPS.*"));
 626                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUPS.ID", new StringParameter(groupId))));
 627                 return loadGroupProperties(database.getSingle(query, groupCreator));
 628         }
 629
 630         /**
 631          * Returns all groups the artist with the given ID belongs to.
 632          *
 633          * @param artistId
 634          *            The ID of the artist
 635          * @return All groups the artist belongs to
 636          * @throws DatabaseException
 637          *             if a database error occurs
 638          */
 639         public Collection<Group> getGroupsByArtist(String artistId) throws DatabaseException {
 640                 Query query = new Query(Type.SELECT, "GROUPS");
 641                 query.addField(new Field("GROUPS.*"));
 642                 query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("GROUPS.ID"), new Field("GROUP_ARTISTS.GROUP_")));
 643                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.ARTIST", new StringParameter(artistId))));
 644                 return database.getMultiple(query, groupCreator);
 645         }
 646
 647         /**
 648          * Loads the properties of the given group.
 649          *
 650          * @param group
 651          *            The group to load the properties for
 652          * @return The group with its properties loaded
 653          * @throws DatabaseException
 654          *             if a database error occurs
 655          */
 656         public Group loadGroupProperties(Group group) throws DatabaseException {
 657                 return loadProperties(group, "GROUP_PROPERTIES", "GROUP_ID");
 658         }
 659
 660         /**
 661          * Loads the properties of the given groups.
 662          *
 663          * @param groups
 664          *            The groups to load the properties for
 665          * @return The groups with their properties loaded
 666          * @throws DatabaseException
 667          *             if a database error occurs
 668          */
 669         public Collection<Group> loadGroupProperties(Collection<Group> groups) throws DatabaseException {
 670                 for (Group group : groups) {
 671                         loadGroupProperties(group);
 672                 }
 673                 return groups;
 674         }
 675
 676         /**
 677          * Creates a group with the given name.
 678          *
 679          * @param name
 680          *            The name of the new group
 681          * @return The new group
 682          * @throws DatabaseException
 683          *             if a database error occurs
 684          */
 685         public Group createGroup(String name) throws DatabaseException {
 686                 Query query = new Query(Type.INSERT, "GROUPS");
 687                 String id = UUID.randomUUID().toString();
 688                 query.addValueField(new ValueField("ID", new StringParameter(id)));
 689                 query.addValueField(new ValueField("NAME", new StringParameter(name)));
 690                 database.insert(query);
 691                 return getGroupById(id);
 692         }
 693
 694         /**
 695          * Saves the given group.
 696          *
 697          * @param group
 698          *            The group to save
 699          * @throws DatabaseException
 700          *             if a database error occurs
 701          */
 702         public void saveGroup(Group group) throws DatabaseException {
 703                 Query query = new Query(Type.UPDATE, "GROUPS");
 704                 query.addValueField(new ValueField("NAME", new StringParameter(group.getName())));
 705                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ID", new StringParameter(group.getId()))));
 706                 database.update(query);
 707                 /* save properties. */
 708                 saveGroupProperties(group);
 709         }
 710
 711         /**
 712          * Saves the properties of the given group.
 713          *
 714          * @param group
 715          *            The group whose properties to save
 716          * @throws DatabaseException
 717          *             if a database error occurs
 718          */
 719         public void saveGroupProperties(Group group) throws DatabaseException {
 720                 saveProperties(group.getProperties(), "GROUP_PROPERTIES", "GROUP_ID", group.getId());
 721         }
 722
 723         /**
 724          * Returns all styles for the track with the given ID.
 725          *
 726          * @param trackId
 727          *            The ID of the track
 728          * @return All styles for the given track
 729          * @throws DatabaseException
 730          *             if a database error occurs
 731          */
 732         public Collection<Style> getStylesByTrack(String trackId) throws DatabaseException {
 733                 Query query = new Query(Type.SELECT, "STYLES");
 734                 query.addField(new Field("STYLES.*"));
 735                 query.addJoin(new Join(JoinType.INNER, "TRACK_STYLES", new Field("STYLES.ID"), new Field("TRACK_STYLES.STYLE")));
 736                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_STYLES.TRACK", new StringParameter(trackId))));
 737                 return database.getMultiple(query, styleCreator);
 738         }
 739
 740         /**
 741          * Returns all parties.
 742          *
 743          * @return All parties
 744          * @throws DatabaseException
 745          *             if a database error occurs
 746          */
 747         public Collection<Party> getAllParties() throws DatabaseException {
 748                 Query query = new Query(Type.SELECT, "PARTIES");
 749                 query.addField(new Field("PARTIES.*"));
 750                 return loadPartyProperties(database.getMultiple(query, partyCreator));
 751         }
 752
 753         /**
 754          * Returns all parties that the track with the given ID was released at.
 755          *
 756          * @param trackId
 757          *            The ID of the track
 758          * @return All parties the track was released at
 759          * @throws DatabaseException
 760          *             if a database error occurs
 761          */
 762         public Collection<Party> getPartiesByTrackId(String trackId) throws DatabaseException {
 763                 Query query = new Query(Type.SELECT, "PARTIES");
 764                 query.addField(new Field("PARTIES.*"));
 765                 query.addJoin(new Join(JoinType.INNER, "PARTY_TRACKS", new Field("PARTY_TRACKS.PARTY"), new Field("PARTIES.ID")));
 766                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("PARTY_TRACKS.TRACK", new StringParameter(trackId))));
 767                 return loadPartyProperties(database.getMultiple(query, partyCreator));
 768         }
 769
 770         /**
 771          * Returns the party with the given ID.
 772          *
 773          * @param partyId
 774          *            The ID of the party
 775          * @return The party with the given ID
 776          * @throws DatabaseException
 777          *             if a database error occurs
 778          */
 779         public Party getPartyById(String partyId) throws DatabaseException {
 780                 Query query = new Query(Type.SELECT, "PARTIES");
 781                 query.addField(new Field("PARTIES.*"));
 782                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("PARTIES.ID", new StringParameter(partyId))));
 783                 return loadPartyProperties(database.getSingle(query, partyCreator));
 784         }
 785
 786         /**
 787          * Loads the properties of the given party.
 788          *
 789          * @param party
 790          *            The party to load the properties for
 791          * @return The party with its properties loaded
 792          * @throws DatabaseException
 793          *             if a database error occurs
 794          */
 795         public Party loadPartyProperties(Party party) throws DatabaseException {
 796                 return loadProperties(party, "PARTY_PROPERTIES", "PARTY");
 797         }
 798
 799         /**
 800          * Loads the properties of the given parties.
 801          *
 802          * @param parties
 803          *            The parties to load the properties for
 804          * @return The parties with their properties loaded
 805          * @throws DatabaseException
 806          *             if a database error occurs
 807          */
 808         public List<Party> loadPartyProperties(List<Party> parties) throws DatabaseException {
 809                 for (Party party : parties) {
 810                         loadPartyProperties(party);
 811                 }
 812                 return parties;
 813         }
 814
 815         /**
 816          * Saves the given party.
 817          *
 818          * @param party
 819          *            The party to save
 820          * @throws DatabaseException
 821          *             if a database error occurs
 822          */
 823         public void saveParty(Party party) throws DatabaseException {
 824                 Query query = new Query(Type.UPDATE, "PARTIES");
 825                 query.addValueField(new ValueField("NAME", new StringParameter(party.getName())));
 826                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ID", new StringParameter(party.getId()))));
 827                 database.update(query);
 828                 savePartyProperties(party);
 829         }
 830
 831         /**
 832          * Saves the properties of the given party.
 833          *
 834          * @param party
 835          *            The party whose properties to save
 836          * @throws DatabaseException
 837          *             if a database error occurs
 838          */
 839         public void savePartyProperties(Party party) throws DatabaseException {
 840                 saveProperties(party.getProperties(), "PARTY_PROPERTIES", "PARTY", party.getId());
 841         }
 842
 843         /**
 844          * Creates a new party with the given name.
 845          *
 846          * @param name
 847          *            The name of the party
 848          * @return The new party
 849          * @throws DatabaseException
 850          *             if a database error occurs
 851          */
 852         public Party createParty(String name) throws DatabaseException {
 853                 Query query = new Query(Type.INSERT, "PARTIES");
 854                 String id = UUID.randomUUID().toString();
 855                 query.addValueField(new ValueField("ID", new StringParameter(id)));
 856                 query.addValueField(new ValueField("NAME", new StringParameter(name)));
 857                 database.insert(query);
 858                 return getPartyById(id);
 859         }
 860
 861         /**
 862          * Returns the user with the given name.
 863          *
 864          * @param username
 865          *            The name of the user
 866          * @return The user, or {@code null} if the user does not exist
 867          * @throws DatabaseException
 868          *             if a database error occurs
 869          */
 870         public User getUserByName(String username) throws DatabaseException {
 871                 Query query = new Query(Type.SELECT, "USERS");
 872                 query.addField(new Field("USERS.*"));
 873                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USERS.NAME", new StringParameter(username))));
 874                 return database.getSingle(query, userCreator);
 875         }
 876
 877         /**
 878          * Returns the user connected with the given OpenID.
 879          *
 880          * @param openId
 881          *            The OpenID to find the user for
 882          * @return The user connected with the given OpenID, or {@code null} if
 883          *         there is no such user
 884          * @throws DatabaseException
 885          *             if a database error occurs
 886          */
 887         public User getUserByOpenId(String openId) throws DatabaseException {
 888                 Query query = new Query(Type.SELECT, "USERS");
 889                 query.addField(new Field("USERS.*"));
 890                 query.addJoin(new Join(JoinType.INNER, "USER_OPENIDS", new Field("USER_OPENIDS.USER"), new Field("USERS.ID")));
 891                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USER_OPENIDS.OPENID", new StringParameter(openId))));
 892                 return database.getSingle(query, userCreator);
 893         }
 894
 895         /**
 896          * Returns all OpenIDs connected with the user with the given ID.
 897          *
 898          * @param userId
 899          *            The ID of the user
 900          * @return All OpenIDs connected with the given user
 901          * @throws DatabaseException
 902          *             if a database error occurs
 903          */
 904         public Collection<String> getOpenIdsByUser(String userId) throws DatabaseException {
 905                 Query query = new Query(Type.SELECT, "USER_OPENIDS");
 906                 query.addField(new Field("USER_OPENIDS.*"));
 907                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USER_OPENIDS.USER", new StringParameter(userId))));
 908                 return database.getMultiple(query, new StringCreator("USER_OPENIDS.OPENID"));
 909         }
 910
 911         //
 912         // PRIVATE METHODS
 913         //
 914
 915         /**
 916          * Loads the properties for the given object.
 917          *
 918          * @param <T>
 919          *            The type of the object
 920          * @param object
 921          *            The object
 922          * @param table
 923          *            The table to load the properties from
 924          * @param type
 925          *            The type of the object (“ARTIST,” “TRACK,” etc.)
 926          * @return The object with its properties loaded
 927          * @throws DatabaseException
 928          *             if a database error occurs
 929          */
 930         private <T extends Base> T loadProperties(final T object, final String table, String type) throws DatabaseException {
 931                 if (object == null) {
 932                         return null;
 933                 }
 934                 Query query = new Query(Type.SELECT, table);
 935                 query.addField(new Field(table + ".PROPERTY"));
 936                 query.addField(new Field(table + ".VALUE"));
 937                 query.addWhereClause(new ValueFieldWhereClause(new ValueField(type, new StringParameter(object.getId()))));
 938                 database.process(query, new ResultProcessor() {
 939
 940                         @Override
 941                         public void processResult(ResultSet resultSet) throws SQLException {
 942                                 if (resultSet.isFirst()) {
 943                                         object.getProperties().removeAll();
 944                                 }
 945                                 object.getProperties().set(resultSet.getString(table + ".PROPERTY"), resultSet.getString(table + ".VALUE"));
 946                         }
 947
 948                 });
 949                 return object;
 950         }
 951
 952         /**
 953          * {@link Artist} implementation that retrieves some attributes (such as
 954          * {@link #getGroups()}, and {@link #getTracks()}) from the
 955          * {@link DataManager} on demand.
 956          *
 957          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 958          */
 959         private class LazyArtist extends DefaultArtist {
 960
 961                 /** Memoizer for the tracks by this artist. */
 962                 private final Memoizer<Void> tracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
 963
 964                         @Override
 965                         public Void call() throws DatabaseException {
 966                                 if (!hasValue("tracks")) {
 967                                         getValue("tracks", Collection.class).set(getTracksByArtist(getId()));
 968                                 }
 969                                 return null;
 970                         }
 971                 });
 972
 973                 /** Memoizer for the groups of this artist. */
 974                 private final Memoizer<Void> groupsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 975
 976                         @Override
 977                         public Void call() throws Exception {
 978                                 if (!hasValue("groups")) {
 979                                         getValue("groups", Collection.class).set(getGroupsByArtist(getId()));
 980                                 }
 981                                 return null;
 982                         }
 983
 984                 });
 985
 986                 /**
 987                  * Creates a new lazy artist.
 988                  *
 989                  * @param id
 990                  *            The ID of the artist
 991                  */
 992                 public LazyArtist(String id) {
 993                         super(id);
 994                 }
 995
 996                 //
 997                 // DEFAULTARTIST METHODS
 998                 //
 999
1000                 /**
1001                  * {@inheritDoc}
1002                  */
1003                 @Override
1004                 public Collection<Group> getGroups() {
1005                         groupsMemoizer.get();
1006                         return super.getGroups();
1007                 }
1008
1009                 /**
1010                  * {@inheritDoc}
1011                  */
1012                 @Override
1013                 public Collection<Track> getTracks() {
1014                         tracksMemoizer.get();
1015                         return super.getTracks();
1016                 }
1017
1018         }
1019
1020         /**
1021          * {@link ObjectCreator} implementation that can create {@link Artist}
1022          * objects. This specific class actually creates {@link LazyArtist}
1023          * instances.
1024          *
1025          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1026          */
1027         private class ArtistCreator implements ObjectCreator<Artist> {
1028
1029                 /**
1030                  * {@inheritDoc}
1031                  */
1032                 @Override
1033                 public Artist createObject(ResultSet resultSet) throws SQLException {
1034                         return new LazyArtist(resultSet.getString("ARTISTS.ID")).setName(resultSet.getString("ARTISTS.NAME"));
1035                 }
1036
1037         }
1038
1039         /**
1040          * {@link Group} implementation that retrieves some attributes (such as
1041          * {@link #getArtists()}) from the {@link DataManager} on demand.
1042          *
1043          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1044          */
1045         private class LazyGroup extends DefaultGroup {
1046
1047                 /** Memoizer for the artist. */
1048                 private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
1049
1050                         @Override
1051                         public Void call() throws Exception {
1052                                 if (!hasValue("artists")) {
1053                                         getValue("artists", Collection.class).set(getArtistsByGroup(getId()));
1054                                 }
1055                                 return null;
1056                         }
1057
1058                 });
1059
1060                 /**
1061                  * Creates a new lazy group.
1062                  *
1063                  * @param id
1064                  *            The ID of the group
1065                  */
1066                 public LazyGroup(String id) {
1067                         super(id);
1068                 }
1069
1070                 //
1071                 // DEFAULTGROUP METHODS
1072                 //
1073
1074                 /**
1075                  * {@inheritDoc}
1076                  */
1077                 @Override
1078                 public Collection<Artist> getArtists() {
1079                         artistsMemoizer.get();
1080                         return super.getArtists();
1081                 }
1082
1083         }
1084
1085         /**
1086          * {@link ObjectCreator} implementation that can create {@link Group}
1087          * objects. This specific implementation creates {@link LazyGroup}
1088          * instances.
1089          *
1090          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1091          */
1092         private class GroupCreator implements ObjectCreator<Group> {
1093
1094                 /**
1095                  * {@inheritDoc}
1096                  */
1097                 @Override
1098                 public Group createObject(ResultSet resultSet) throws SQLException {
1099                         return new LazyGroup(resultSet.getString("GROUPS.ID")).setName(resultSet.getString("GROUPS.NAME")).setUrl(resultSet.getString("GROUPS.URL"));
1100                 }
1101
1102         }
1103
1104         /**
1105          * {@link Track} implementation that retrieves some attributes (such as
1106          * {@link #getArtists()}, and {@link #getStyles()}) from the
1107          * {@link DataManager} on demand.
1108          *
1109          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1110          */
1111         private class LazyTrack extends DefaultTrack {
1112
1113                 /** Memoizer for the artists. */
1114                 private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
1115
1116                         @Override
1117                         public Void call() throws Exception {
1118                                 if (!hasValue("artists")) {
1119                                         getValue("artists", List.class).set(getArtistsByTrack(getId()));
1120                                 }
1121                                 return null;
1122                         }
1123
1124                 });
1125
1126                 /** Memoizer for the styles. */
1127                 private final Memoizer<Void> stylesMemoizer = new Memoizer<Void>(new Callable<Void>() {
1128
1129                         @Override
1130                         public Void call() throws Exception {
1131                                 if (!hasValue("styles")) {
1132                                         getValue("styles", Collection.class).set(getStylesByTrack(getId()));
1133                                 }
1134                                 return null;
1135                         }
1136
1137                 });
1138
1139                 /** Memoizer for the remix artists. */
1140                 private final Memoizer<Void> remixArtistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
1141
1142                         @Override
1143                         public Void call() throws Exception {
1144                                 if (!hasValue("remixArtists")) {
1145                                         getValue("remixArtists", List.class).set(getRemixArtistsByTrack(getId()));
1146                                 }
1147                                 return null;
1148                         }
1149
1150                 });
1151
1152                 /** Memoizer for the track derivatives. */
1153                 private final Memoizer<Void> derivativesMemoizer = new Memoizer<Void>(new Callable<Void>() {
1154
1155                         @Override
1156                         public Void call() throws Exception {
1157                                 if (!hasValue("derivatives")) {
1158                                         getValue("derivatives", Collection.class).set(getTrackDerivativesByTrack(getId()));
1159                                 }
1160                                 return null;
1161                         }
1162
1163                 });
1164
1165                 /** Memoizer for the related tracks. */
1166                 private final Memoizer<Void> relatedTracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
1167
1168                         @Override
1169                         public Void call() throws Exception {
1170                                 if (!hasValue("relatedTracks")) {
1171                                         getValue("relatedTracks", Map.class).set(getRelatedTracksByTrack(getId()));
1172                                 }
1173                                 return null;
1174                         }
1175
1176                 });
1177
1178                 /**
1179                  * Creates a new track.
1180                  *
1181                  * @param id
1182                  *            The ID of the track
1183                  */
1184                 public LazyTrack(String id) {
1185                         super(id);
1186                 }
1187
1188                 //
1189                 // DEFAULTTRACK METHODS
1190                 //
1191
1192                 /**
1193                  * {@inheritDoc}
1194                  */
1195                 @Override
1196                 public List<Artist> getArtists() {
1197                         artistsMemoizer.get();
1198                         return super.getArtists();
1199                 }
1200
1201                 /**
1202                  * {@inheritDoc}
1203                  */
1204                 @Override
1205                 public Collection<Style> getStyles() {
1206                         stylesMemoizer.get();
1207                         return super.getStyles();
1208                 }
1209
1210                 /**
1211                  * {@inheritDoc}
1212                  */
1213                 @Override
1214                 public List<Artist> getRemixArtists() {
1215                         remixArtistsMemoizer.get();
1216                         return super.getRemixArtists();
1217                 }
1218
1219                 /**
1220                  * {@inheritDoc}
1221                  */
1222                 @Override
1223                 public Collection<TrackDerivative> getDerivatives() {
1224                         derivativesMemoizer.get();
1225                         return super.getDerivatives();
1226                 }
1227
1228                 /**
1229                  * {@inheritDoc}
1230                  */
1231                 @Override
1232                 public Map<Relationship, Collection<Track>> getRelatedTracks() {
1233                         relatedTracksMemoizer.get();
1234                         return super.getRelatedTracks();
1235                 }
1236
1237                 /**
1238                  * {@inheritDoc}
1239                  */
1240                 @Override
1241                 public Collection<Party> getParties() {
1242                         if (!hasValue("parties")) {
1243                                 try {
1244                                         getValue("parties", Collection.class).set(getPartiesByTrackId(getId()));
1245                                 } catch (DatabaseException de1) {
1246                                         throw new RuntimeException("Could not load Parties for Track " + getId() + ".", de1);
1247                                 }
1248                         }
1249                         return super.getParties();
1250                 }
1251
1252         }
1253
1254         /**
1255          * {@link ObjectCreator} implementation that can create {@link Track}
1256          * objects. This specific implementation creates {@link LazyTrack}
1257          * instances.
1258          *
1259          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1260          */
1261         private class TrackCreator implements ObjectCreator<Track> {
1262
1263                 /**
1264                  * {@inheritDoc}
1265                  */
1266                 @Override
1267                 public Track createObject(ResultSet resultSet) throws SQLException {
1268                         return new LazyTrack(resultSet.getString("TRACKS.ID")).setName(resultSet.getString("TRACKS.NAME")).setRemix(resultSet.getString("TRACKS.REMIX"));
1269                 }
1270
1271         }
1272
1273         /**
1274          * {@link ObjectCreator} implementation that can create
1275          * {@link TrackDerivative} objects.
1276          *
1277          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1278          */
1279         private class TrackDerivativeCreator implements ObjectCreator<TrackDerivative> {
1280
1281                 /**
1282                  * {@inheritDoc}
1283                  */
1284                 @Override
1285                 public TrackDerivative createObject(ResultSet resultSet) throws SQLException {
1286                         return new DefaultTrackDerivative(resultSet.getString("TRACK_DERIVATIVES.ID"));
1287                 }
1288
1289         }
1290
1291         /**
1292          * {@link ObjectCreator} implementation that can create {@link Style}
1293          * objects.
1294          *
1295          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1296          */
1297         private class StyleCreator implements ObjectCreator<Style> {
1298
1299                 /**
1300                  * {@inheritDoc}
1301                  */
1302                 @Override
1303                 public Style createObject(ResultSet resultSet) throws SQLException {
1304                         return new DefaultStyle(resultSet.getString("STYLES.ID")).setName(resultSet.getString("STYLES.NAME"));
1305                 }
1306
1307         }
1308
1309         /**
1310          * {@link Party} implementation that loads additional information only on
1311          * demand.
1312          *
1313          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1314          */
1315         private class LazyParty extends DefaultParty {
1316
1317                 /**
1318                  * Creates a new party.
1319                  *
1320                  * @param id
1321                  *            The ID of the party
1322                  */
1323                 public LazyParty(String id) {
1324                         super(id);
1325                 }
1326
1327                 //
1328                 // PARTY METHODS
1329                 //
1330
1331                 /**
1332                  * {@inheritDoc}
1333                  */
1334                 @Override
1335                 public Collection<Track> getReleases() {
1336                         if (!hasValue("releases")) {
1337                                 try {
1338                                         getValue("releases", Collection.class).set(getTracksByParty(getId()));
1339                                 } catch (DatabaseException de1) {
1340                                         throw new RuntimeException("Could not loaded Tracks for Party " + getId() + ".", de1);
1341                                 }
1342                         }
1343                         return super.getReleases();
1344                 }
1345
1346         }
1347
1348         /**
1349          * {@link ObjectCreator} implementation that can create {@link Party}
1350          * objects.
1351          *
1352          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1353          */
1354         private class PartyCreator implements ObjectCreator<Party> {
1355
1356                 /**
1357                  * {@inheritDoc}
1358                  */
1359                 @Override
1360                 public Party createObject(ResultSet resultSet) throws SQLException {
1361                         return new LazyParty(resultSet.getString("PARTIES.ID")).setName(resultSet.getString("PARTIES.NAME"));
1362                 }
1363
1364         }
1365
1366         /**
1367          * {@link User} implementation that retrieves some attributes (such as
1368          * {@link #getOpenIds()}) from the {@link DataManager} on demand.
1369          *
1370          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1371          */
1372         private class LazyUser extends DefaultUser {
1373
1374                 /** Memoizer for a user’s OpenIDs. */
1375                 private final Memoizer<Void> openIdMemoizer = new Memoizer<Void>(new Callable<Void>() {
1376
1377                         @Override
1378                         public Void call() throws Exception {
1379                                 if (!hasValue("openIds")) {
1380                                         getValue("openIds", Collection.class).set(getOpenIdsByUser(getId()));
1381                                 }
1382                                 return null;
1383                         }
1384                 });
1385
1386                 /**
1387                  * Creates a new user.
1388                  *
1389                  * @param id
1390                  *            The ID of the user
1391                  */
1392                 public LazyUser(String id) {
1393                         super(id);
1394                 }
1395
1396                 /**
1397                  * {@inheritDoc}
1398                  */
1399                 @Override
1400                 public Collection<String> getOpenIds() {
1401                         openIdMemoizer.get();
1402                         return super.getOpenIds();
1403                 }
1404
1405         }
1406
1407         /**
1408          * {@link ObjectCreator} implementation that can create {@link User}
1409          * objects. This specific implementation creates {@link LazyUser} instances.
1410          *
1411          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
1412          */
1413         private class UserCreator implements ObjectCreator<User> {
1414
1415                 /**
1416                  * {@inheritDoc}
1417                  */
1418                 @Override
1419                 public User createObject(ResultSet resultSet) throws SQLException {
1420                         return new LazyUser(resultSet.getString("USERS.ID")).setName(resultSet.getString("USERS.NAME")).setPasswordHash(resultSet.getString("USERS.PASSWORD")).setLevel(resultSet.getInt("USERS.LEVEL"));
1421                 }
1422
1423         }
1424
1425 }