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.StringParameter;
  42 import net.pterodactylus.util.database.Query;
  43 import net.pterodactylus.util.database.Query.Type;
  44 import net.pterodactylus.util.database.ResultProcessor;
  45 import net.pterodactylus.util.database.ValueField;
  46 import net.pterodactylus.util.database.ValueFieldWhereClause;
  47
  48 /**
  49  * Interface between the database and the application.
  50  *
  51  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  52  */
  53 public class DataManager {
  54
  55         /** The artist object creator. */
  56         @SuppressWarnings("synthetic-access")
  57         private final ObjectCreator<Artist> artistCreator = new ArtistCreator();
  58
  59         /** The group object creator. */
  60         @SuppressWarnings("synthetic-access")
  61         private final ObjectCreator<Group> groupCreator = new GroupCreator();
  62
  63         /** The track object creator. */
  64         @SuppressWarnings("synthetic-access")
  65         private final ObjectCreator<Track> trackCreator = new TrackCreator();
  66
  67         /** The track object creator. */
  68         @SuppressWarnings("synthetic-access")
  69         private final ObjectCreator<TrackDerivative> trackDerivativeCreator = new TrackDerivativeCreator();
  70
  71         /** The style object creator. */
  72         @SuppressWarnings("synthetic-access")
  73         private final ObjectCreator<Style> styleCreator = new StyleCreator();
  74
  75         /** The {@link User} object creator. */
  76         @SuppressWarnings("synthetic-access")
  77         private final ObjectCreator<User> userCreator = new UserCreator();
  78
  79         /** The database. */
  80         private final Database database;
  81
  82         /**
  83          * Creates a new data manager.
  84          *
  85          * @param database
  86          *            The database to operate on
  87          */
  88         public DataManager(Database database) {
  89                 this.database = database;
  90         }
  91
  92         /**
  93          * Returns all artists.
  94          *
  95          * @return All artists
  96          * @throws DatabaseException
  97          *             if a database error occurs
  98          */
  99         public Collection<Artist> getAllArtists() throws DatabaseException {
 100                 Query query = new Query(Type.SELECT, "ARTISTS");
 101                 query.addField(new Field("ARTISTS.*"));
 102                 return loadProperties(database.getMultiple(query, artistCreator));
 103         }
 104
 105         /**
 106          * Returns the artist with the given ID.
 107          *
 108          * @param id
 109          *            The ID of the artist
 110          * @return The artist with the given ID, or {@code null} if there is no
 111          *         artist with the given ID
 112          * @throws DatabaseException
 113          *             if a database error occurs
 114          */
 115         public Artist getArtistById(String id) throws DatabaseException {
 116                 Query query = new Query(Type.SELECT, "ARTISTS");
 117                 query.addField(new Field("ARTISTS.*"));
 118                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ARTISTS.ID", new StringParameter(id))));
 119                 return loadProperties(database.getSingle(query, artistCreator));
 120         }
 121
 122         /**
 123          * Returns all artists that belong to the group with the given ID.
 124          *
 125          * @param groupId
 126          *            The ID of the group
 127          * @return All artists belonging to the given group
 128          * @throws DatabaseException
 129          *             if a database error occurs
 130          */
 131         public Collection<Artist> getArtistsByGroup(String groupId) throws DatabaseException {
 132                 Query query = new Query(Type.SELECT, "ARTISTS");
 133                 query.addField(new Field("ARTISTS.*"));
 134                 query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("ARTISTS.ID"), new Field("GROUP_ARTISTS.ARTIST")));
 135                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.GROUP_", new StringParameter(groupId))));
 136                 return loadProperties(database.getMultiple(query, artistCreator));
 137         }
 138
 139         /**
 140          * Returns all artists involved in the track with the given ID.
 141          *
 142          * @param trackId
 143          *            The ID of the track
 144          * @return All artists involved in the track, in preferred order
 145          * @throws DatabaseException
 146          *             if a database error occurs
 147          */
 148         public List<Artist> getArtistsByTrack(String trackId) throws DatabaseException {
 149                 Query query = new Query(Type.SELECT, "ARTISTS");
 150                 query.addField(new Field("ARTISTS.*"));
 151                 query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACK_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
 152                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(trackId))));
 153                 query.addOrderField(new OrderField(new Field("TRACK_ARTISTS.DISPLAY_ORDER")));
 154                 return loadProperties(database.getMultiple(query, artistCreator));
 155         }
 156
 157         /**
 158          * Creates a new artist with the given name.
 159          *
 160          * @param name
 161          *            The name of the artist
 162          * @return The created artist
 163          * @throws DatabaseException
 164          *             if a database error occurs
 165          */
 166         public Artist createArtist(String name) throws DatabaseException {
 167                 Query query = new Query(Type.INSERT, "ARTISTS");
 168                 String id = UUID.randomUUID().toString();
 169                 query.addValueField(new ValueField("ID", new StringParameter(id)));
 170                 query.addValueField(new ValueField("NAME", new StringParameter(name)));
 171                 database.insert(query);
 172                 return loadProperties(getArtistById(id));
 173         }
 174
 175         /**
 176          * Saves the given artist.
 177          *
 178          * @param artist
 179          *            The artist to save
 180          * @throws DatabaseException
 181          *             if a database error occurs
 182          */
 183         public void saveArtist(Artist artist) throws DatabaseException {
 184                 Query query = new Query(Type.UPDATE, "ARTISTS");
 185                 query.addValueField(new ValueField("NAME", new StringParameter(artist.getName())));
 186                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ID", new StringParameter(artist.getId()))));
 187                 database.update(query);
 188                 saveArtistProperties(artist);
 189         }
 190
 191         /**
 192          * Saves the properties of the given artist.
 193          *
 194          * @param artist
 195          *            The artist whose properties to save
 196          * @throws DatabaseException
 197          *             if a database error occurs
 198          */
 199         public void saveArtistProperties(Artist artist) throws DatabaseException {
 200                 saveProperties(artist.getProperties(), "ARTIST_PROPERTIES", "ARTIST", artist.getId());
 201         }
 202
 203         /**
 204          * Saves the given properties to the given table for the given principal.
 205          *
 206          * @param properties
 207          *            The properties to save
 208          * @param table
 209          *            The table in which to save the properties
 210          * @param type
 211          *            The type of the principal (e. g. “ARTIST” or “TRACK”)
 212          * @param id
 213          *            The ID of the principial
 214          * @throws DatabaseException
 215          *             if a database error occurs
 216          */
 217         public void saveProperties(Properties properties, String table, String type, String id) throws DatabaseException {
 218                 if (!properties.isDirty()) {
 219                         return;
 220                 }
 221                 Query query = new Query(Type.DELETE, table);
 222                 query.addWhereClause(new ValueFieldWhereClause(new ValueField(type, new StringParameter(id))));
 223                 database.update(query);
 224                 for (Entry<String, String> property : properties) {
 225                         Query insertQuery = new Query(Type.INSERT, table);
 226                         insertQuery.addValueField(new ValueField(type, new StringParameter(id)));
 227                         insertQuery.addValueField(new ValueField("PROPERTY", new StringParameter(property.getKey())));
 228                         insertQuery.addValueField(new ValueField("VALUE", new StringParameter(property.getValue())));
 229                         database.insert(insertQuery);
 230                 }
 231                 properties.resetDirty();
 232         }
 233
 234         /**
 235          * Loads the properties for an artist.
 236          *
 237          * @param artist
 238          *            The artist to load the properties for
 239          * @return The artist
 240          * @throws DatabaseException
 241          *             if a database error occurs
 242          */
 243         public Artist loadProperties(final Artist artist) throws DatabaseException {
 244                 Query query = new Query(Type.SELECT, "ARTIST_PROPERTIES");
 245                 query.addField(new Field("ARTIST_PROPERTIES.PROPERTY"));
 246                 query.addField(new Field("ARTIST_PROPERTIES.VALUE"));
 247                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ARTIST", new StringParameter(artist.getId()))));
 248                 database.process(query, new ResultProcessor() {
 249
 250                         @Override
 251                         public void processResult(ResultSet resultSet) throws SQLException {
 252                                 if (resultSet.isFirst()) {
 253                                         artist.getProperties().removeAll();
 254                                 }
 255                                 artist.getProperties().set(resultSet.getString("ARTIST_PROPERTIES.PROPERTY"), resultSet.getString("ARTIST_PROPERTIES.VALUE"));
 256                         }
 257
 258                 });
 259                 return artist;
 260         }
 261
 262         /**
 263          * Loads the properties of all given artists.
 264          *
 265          * @param artists
 266          *            The artists to load the properties for
 267          * @return The list of artists
 268          * @throws DatabaseException
 269          *             if a database error occurs
 270          */
 271         public List<Artist> loadProperties(List<Artist> artists) throws DatabaseException {
 272                 for (Artist artist : artists) {
 273                         loadProperties(artist);
 274                 }
 275                 return artists;
 276         }
 277
 278         /**
 279          * Returns all remix artists involved in the track with the given ID.
 280          *
 281          * @param trackId
 282          *            The ID of the track
 283          * @return All remix artists involved in the track, in preferred order
 284          * @throws DatabaseException
 285          *             if a database error occurs
 286          */
 287         public List<Artist> getRemixArtistsByTrack(String trackId) throws DatabaseException {
 288                 Query query = new Query(Type.SELECT, "ARTISTS");
 289                 query.addField(new Field("ARTISTS.*"));
 290                 query.addJoin(new Join(JoinType.INNER, "TRACK_REMIX_ARTISTS", new Field("TRACK_REMIX_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
 291                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_REMIX_ARTISTS.TRACK", new StringParameter(trackId))));
 292                 query.addOrderField(new OrderField(new Field("TRACK_REMIX_ARTISTS.DISPLAY_ORDER")));
 293                 return database.getMultiple(query, artistCreator);
 294         }
 295
 296         /**
 297          * Returns all related tracks for the track with the given ID.
 298          *
 299          * @param trackId
 300          *            The ID of the tracks
 301          * @return A mapping from relationship to all tracks that match the relation
 302          * @throws DatabaseException
 303          *             if a database error occurs
 304          */
 305         public Map<Relationship, Collection<Track>> getRelatedTracksByTrack(String trackId) throws DatabaseException {
 306                 Query query = new Query(Type.SELECT, "TRACKS");
 307                 query.addField(new Field("TRACKS.*"));
 308                 query.addField(new Field("TRACK_RELATIONS.*"));
 309                 query.addJoin(new Join(JoinType.INNER, "TRACK_RELATIONS", new Field("TRACK_RELATIONS.TRACK"), new Field("TRACK_RELATIONS.RELATED_TRACK")));
 310                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_RELATIONS.TRACK", new StringParameter(trackId))));
 311                 final Map<Relationship, Collection<Track>> relatedTracks = new EnumMap<Relationship, Collection<Track>>(Relationship.class);
 312                 database.process(query, new ResultProcessor() {
 313
 314                         @Override
 315                         @SuppressWarnings("synthetic-access")
 316                         public void processResult(ResultSet resultSet) throws SQLException {
 317                                 Track track = trackCreator.createObject(resultSet);
 318                                 Relationship relationship = Relationship.valueOf(resultSet.getString("TRACK_RELATIONS.RELATIONSHIP"));
 319                                 if (!relatedTracks.containsKey(relationship)) {
 320                                         relatedTracks.put(relationship, new HashSet<Track>());
 321                                 }
 322                                 relatedTracks.get(relationship).add(track);
 323                         }
 324                 });
 325                 return relatedTracks;
 326         }
 327
 328         /**
 329          * Returns the track with the given ID.
 330          *
 331          * @param id
 332          *            The ID of the track
 333          * @return The track with the given ID, or {@code null} if there is no such
 334          *         track
 335          * @throws DatabaseException
 336          *             if a database error occurs
 337          */
 338         public Track getTrackById(String id) throws DatabaseException {
 339                 Query query = new Query(Type.SELECT, "TRACKS");
 340                 query.addField(new Field("TRACKS.*"));
 341                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACKS.ID", new StringParameter(id))));
 342                 return database.getSingle(query, trackCreator);
 343         }
 344
 345         /**
 346          * Returns all tracks by the artist with the given ID.
 347          *
 348          * @param artistId
 349          *            The ID of the artist
 350          * @return All tracks by the given artist
 351          * @throws DatabaseException
 352          *             if a database error occurs
 353          */
 354         public Collection<Track> getTracksByArtist(String artistId) throws DatabaseException {
 355                 Query query = new Query(Type.SELECT, "TRACKS");
 356                 query.addField(new Field("TRACKS.*"));
 357                 query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACKS.ID"), new Field("TRACK_ARTISTS.TRACK")));
 358                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.ARTIST", new StringParameter(artistId))));
 359                 return database.getMultiple(query, trackCreator);
 360         }
 361
 362         /**
 363          * Returns all groups the artist with the given ID belongs to.
 364          *
 365          * @param artistId
 366          *            The ID of the artist
 367          * @return All groups the artist belongs to
 368          * @throws DatabaseException
 369          *             if a database error occurs
 370          */
 371         public Collection<Group> getGroupsByArtist(String artistId) throws DatabaseException {
 372                 Query query = new Query(Type.SELECT, "GROUPS");
 373                 query.addField(new Field("GROUPS.*"));
 374                 query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("GROUPS.ID"), new Field("GROUP_ARTISTS.GROUP_")));
 375                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.ARTIST", new StringParameter(artistId))));
 376                 return database.getMultiple(query, groupCreator);
 377         }
 378
 379         /**
 380          * Returns all styles for the track with the given ID.
 381          *
 382          * @param trackId
 383          *            The ID of the track
 384          * @return All styles for the given track
 385          * @throws DatabaseException
 386          *             if a database error occurs
 387          */
 388         public Collection<Style> getStylesByTrack(String trackId) throws DatabaseException {
 389                 Query query = new Query(Type.SELECT, "STYLES");
 390                 query.addField(new Field("STYLES.*"));
 391                 query.addJoin(new Join(JoinType.INNER, "TRACK_STYLES", new Field("STYLES.ID"), new Field("TRACK_STYLES.STYLE")));
 392                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_STYLES.TRACK", new StringParameter(trackId))));
 393                 return database.getMultiple(query, styleCreator);
 394         }
 395
 396         /**
 397          * Returns the user with the given name.
 398          *
 399          * @param username
 400          *            The name of the user
 401          * @return The user, or {@code null} if the user does not exist
 402          * @throws DatabaseException
 403          *             if a database error occurs
 404          */
 405         public User getUserByName(String username) throws DatabaseException {
 406                 Query query = new Query(Type.SELECT, "USERS");
 407                 query.addField(new Field("USERS.*"));
 408                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USERS.NAME", new StringParameter(username))));
 409                 return database.getSingle(query, userCreator);
 410         }
 411
 412         /**
 413          * Returns the user connected with the given OpenID.
 414          *
 415          * @param openId
 416          *            The OpenID to find the user for
 417          * @return The user connected with the given OpenID, or {@code null} if
 418          *         there is no such user
 419          * @throws DatabaseException
 420          *             if a database error occurs
 421          */
 422         public User getUserByOpenId(String openId) throws DatabaseException {
 423                 Query query = new Query(Type.SELECT, "USERS");
 424                 query.addField(new Field("USERS.*"));
 425                 query.addJoin(new Join(JoinType.INNER, "USER_OPENIDS", new Field("USER_OPENIDS.USER"), new Field("USERS.ID")));
 426                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USER_OPENIDS.OPENID", new StringParameter(openId))));
 427                 return database.getSingle(query, userCreator);
 428         }
 429
 430         /**
 431          * Returns all OpenIDs connected with the user with the given ID.
 432          *
 433          * @param userId
 434          *            The ID of the user
 435          * @return All OpenIDs connected with the given user
 436          * @throws DatabaseException
 437          *             if a database error occurs
 438          */
 439         public Collection<String> getOpenIdsByUser(String userId) throws DatabaseException {
 440                 Query query = new Query(Type.SELECT, "USER_OPENIDS");
 441                 query.addField(new Field("USER_OPENIDS.*"));
 442                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USER_OPENIDS.USER", new StringParameter(userId))));
 443                 return database.getMultiple(query, new StringCreator("USER_OPENIDS.OPENID"));
 444         }
 445
 446         //
 447         // PRIVATE METHODS
 448         //
 449
 450         /**
 451          * Loads the properties for the given object.
 452          *
 453          * @param <T>
 454          *            The type of the object
 455          * @param object
 456          *            The object
 457          * @param table
 458          *            The table to load the properties from
 459          * @param type
 460          *            The type of the object (“ARTIST,” “TRACK,” etc.)
 461          * @return The object with its properties loaded
 462          * @throws DatabaseException
 463          *             if a database error occurs
 464          */
 465         private <T extends Base> T loadProperties(final T object, final String table, String type) throws DatabaseException {
 466                 Query query = new Query(Type.SELECT, table);
 467                 query.addField(new Field(table + ".PROPERTY"));
 468                 query.addField(new Field(table + ".VALUE"));
 469                 query.addWhereClause(new ValueFieldWhereClause(new ValueField(type, new StringParameter(object.getId()))));
 470                 database.process(query, new ResultProcessor() {
 471
 472                         @Override
 473                         public void processResult(ResultSet resultSet) throws SQLException {
 474                                 if (resultSet.isFirst()) {
 475                                         object.getProperties().removeAll();
 476                                 }
 477                                 object.getProperties().set(resultSet.getString(table + ".PROPERTY"), resultSet.getString(table + ".VALUE"));
 478                         }
 479
 480                 });
 481                 return object;
 482         }
 483
 484         /**
 485          * {@link Artist} implementation that retrieves some attributes (such as
 486          * {@link #getGroups()}, and {@link #getTracks()}) from the
 487          * {@link DataManager} on demand.
 488          *
 489          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 490          */
 491         private class LazyArtist extends DefaultArtist {
 492
 493                 /** Memoizer for the tracks by this artist. */
 494                 private final Memoizer<Void> tracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
 495                         @Override
 496                         public Void call() throws DatabaseException {
 497                                 if (!hasValue("tracks")) {
 498                                         getValue("tracks", Collection.class).set(getTracksByArtist(getId()));
 499                                 }
 500                                 return null;
 501                         }
 502                 });
 503
 504                 /** Memoizer for the groups of this artist. */
 505                 private final Memoizer<Void> groupsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 506
 507                         @Override
 508                         public Void call() throws Exception {
 509                                 if (!hasValue("groups")) {
 510                                         getValue("groups", Collection.class).set(getGroupsByArtist(getId()));
 511                                 }
 512                                 return null;
 513                         }
 514
 515                 });
 516
 517                 /**
 518                  * Creates a new lazy artist.
 519                  *
 520                  * @param id
 521                  *            The ID of the artist
 522                  */
 523                 public LazyArtist(String id) {
 524                         super(id);
 525                 }
 526
 527                 //
 528                 // DEFAULTARTIST METHODS
 529                 //
 530
 531                 /**
 532                  * {@inheritDoc}
 533                  */
 534                 @Override
 535                 public Collection<Group> getGroups() {
 536                         groupsMemoizer.get();
 537                         return super.getGroups();
 538                 }
 539
 540                 /**
 541                  * {@inheritDoc}
 542                  */
 543                 @Override
 544                 public Collection<Track> getTracks() {
 545                         tracksMemoizer.get();
 546                         return super.getTracks();
 547                 }
 548
 549         }
 550
 551         /**
 552          * {@link ObjectCreator} implementation that can create {@link Artist}
 553          * objects. This specific class actually creates {@link LazyArtist}
 554          * instances.
 555          *
 556          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 557          */
 558         private class ArtistCreator implements ObjectCreator<Artist> {
 559
 560                 /**
 561                  * {@inheritDoc}
 562                  */
 563                 @Override
 564                 public Artist createObject(ResultSet resultSet) throws SQLException {
 565                         return new LazyArtist(resultSet.getString("ARTISTS.ID")).setName(resultSet.getString("ARTISTS.NAME"));
 566                 }
 567
 568         }
 569
 570         /**
 571          * {@link Group} implementation that retrieves some attributes (such as
 572          * {@link #getArtists()}) from the {@link DataManager} on demand.
 573          *
 574          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 575          */
 576         private class LazyGroup extends DefaultGroup {
 577
 578                 /** Memoizer for the artist. */
 579                 private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 580
 581                         @Override
 582                         public Void call() throws Exception {
 583                                 if (!hasValue("artists")) {
 584                                         getValue("artists", Collection.class).set(getArtistsByGroup(getId()));
 585                                 }
 586                                 return null;
 587                         }
 588
 589                 });
 590
 591                 /**
 592                  * Creates a new lazy group.
 593                  *
 594                  * @param id
 595                  *            The ID of the group
 596                  */
 597                 public LazyGroup(String id) {
 598                         super(id);
 599                 }
 600
 601                 //
 602                 // DEFAULTGROUP METHODS
 603                 //
 604
 605                 /**
 606                  * {@inheritDoc}
 607                  */
 608                 @Override
 609                 public Collection<Artist> getArtists() {
 610                         artistsMemoizer.get();
 611                         return super.getArtists();
 612                 }
 613
 614         }
 615
 616         /**
 617          * {@link ObjectCreator} implementation that can create {@link Group}
 618          * objects. This specific implementation creates {@link LazyGroup}
 619          * instances.
 620          *
 621          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 622          */
 623         private class GroupCreator implements ObjectCreator<Group> {
 624
 625                 /**
 626                  * {@inheritDoc}
 627                  */
 628                 @Override
 629                 public Group createObject(ResultSet resultSet) throws SQLException {
 630                         return new LazyGroup(resultSet.getString("GROUPS.ID")).setName(resultSet.getString("GROUPS.NAME")).setUrl(resultSet.getString("GROUPS.URL"));
 631                 }
 632
 633         }
 634
 635         /**
 636          * {@link Track} implementation that retrieves some attributes (such as
 637          * {@link #getArtists()}, and {@link #getStyles()}) from the
 638          * {@link DataManager} on demand.
 639          *
 640          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 641          */
 642         private class LazyTrack extends DefaultTrack {
 643
 644                 /** Memoizer for the artists. */
 645                 private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 646
 647                         @Override
 648                         public Void call() throws Exception {
 649                                 if (!hasValue("artists")) {
 650                                         getValue("artists", List.class).set(getArtistsByTrack(getId()));
 651                                 }
 652                                 return null;
 653                         }
 654
 655                 });
 656
 657                 /** Memoizer for the styles. */
 658                 private final Memoizer<Void> stylesMemoizer = new Memoizer<Void>(new Callable<Void>() {
 659
 660                         @Override
 661                         public Void call() throws Exception {
 662                                 if (!hasValue("styles")) {
 663                                         getValue("styles", Collection.class).set(getStylesByTrack(getId()));
 664                                 }
 665                                 return null;
 666                         }
 667
 668                 });
 669
 670                 /** Memoizer for the remix artists. */
 671                 private final Memoizer<Void> remixArtistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 672
 673                         @Override
 674                         public Void call() throws Exception {
 675                                 if (!hasValue("remixArtists")) {
 676                                         getValue("remixArtists", List.class).set(getRemixArtistsByTrack(getId()));
 677                                 }
 678                                 return null;
 679                         }
 680
 681                 });
 682
 683                 /** Memoizer for the related tracks. */
 684                 private final Memoizer<Void> relatedTracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
 685
 686                         @Override
 687                         public Void call() throws Exception {
 688                                 if (!hasValue("relatedTracks")) {
 689                                         getValue("relatedTracks", Map.class).set(getRelatedTracksByTrack(getId()));
 690                                 }
 691                                 return null;
 692                         }
 693                 });
 694
 695                 /**
 696                  * Creates a new track.
 697                  *
 698                  * @param id
 699                  *            The ID of the track
 700                  */
 701                 public LazyTrack(String id) {
 702                         super(id);
 703                 }
 704
 705                 //
 706                 // DEFAULTTRACK METHODS
 707                 //
 708
 709                 /**
 710                  * {@inheritDoc}
 711                  */
 712                 @Override
 713                 public List<Artist> getArtists() {
 714                         artistsMemoizer.get();
 715                         return super.getArtists();
 716                 }
 717
 718                 /**
 719                  * {@inheritDoc}
 720                  */
 721                 @Override
 722                 public Collection<Style> getStyles() {
 723                         stylesMemoizer.get();
 724                         return super.getStyles();
 725                 }
 726
 727                 /**
 728                  * {@inheritDoc}
 729                  */
 730                 @Override
 731                 public List<Artist> getRemixArtists() {
 732                         remixArtistsMemoizer.get();
 733                         return super.getRemixArtists();
 734                 }
 735
 736                 /**
 737                  * {@inheritDoc}
 738                  */
 739                 @Override
 740                 public Map<Relationship, Collection<Track>> getRelatedTracks() {
 741                         relatedTracksMemoizer.get();
 742                         return super.getRelatedTracks();
 743                 }
 744
 745         }
 746
 747         /**
 748          * {@link ObjectCreator} implementation that can create {@link Track}
 749          * objects. This specific implementation creates {@link LazyTrack}
 750          * instances.
 751          *
 752          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 753          */
 754         private class TrackCreator implements ObjectCreator<Track> {
 755
 756                 /**
 757                  * {@inheritDoc}
 758                  */
 759                 @Override
 760                 public Track createObject(ResultSet resultSet) throws SQLException {
 761                         return new LazyTrack(resultSet.getString("TRACKS.ID")).setName(resultSet.getString("TRACKS.NAME")).setRemix(resultSet.getString("TRACKS.REMIX"));
 762                 }
 763
 764         }
 765
 766         /**
 767          * {@link ObjectCreator} implementation that can create
 768          * {@link TrackDerivative} objects.
 769          *
 770          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 771          */
 772         private class TrackDerivativeCreator implements ObjectCreator<TrackDerivative> {
 773
 774                 /**
 775                  * {@inheritDoc}
 776                  */
 777                 @Override
 778                 public TrackDerivative createObject(ResultSet resultSet) throws SQLException {
 779                         return new DefaultTrackDerivative(resultSet.getString("TRACK_DERIVATIVES.ID"));
 780                 }
 781
 782         }
 783
 784         /**
 785          * {@link ObjectCreator} implementation that can create {@link Style}
 786          * objects.
 787          *
 788          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 789          */
 790         private class StyleCreator implements ObjectCreator<Style> {
 791
 792                 /**
 793                  * {@inheritDoc}
 794                  */
 795                 @Override
 796                 public Style createObject(ResultSet resultSet) throws SQLException {
 797                         return new DefaultStyle(resultSet.getString("STYLES.ID")).setName(resultSet.getString("STYLES.NAME"));
 798                 }
 799
 800         }
 801
 802         /**
 803          * {@link User} implementation that retrieves some attributes (such as
 804          * {@link #getOpenIds()}) from the {@link DataManager} on demand.
 805          *
 806          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 807          */
 808         private class LazyUser extends DefaultUser {
 809
 810                 /** Memoizer for a user’s OpenIDs. */
 811                 private final Memoizer<Void> openIdMemoizer = new Memoizer<Void>(new Callable<Void>() {
 812
 813                         @Override
 814                         public Void call() throws Exception {
 815                                 if (!hasValue("openIds")) {
 816                                         getValue("openIds", Collection.class).set(getOpenIdsByUser(getId()));
 817                                 }
 818                                 return null;
 819                         }
 820                 });
 821
 822                 /**
 823                  * Creates a new user.
 824                  *
 825                  * @param id
 826                  *            The ID of the user
 827                  */
 828                 public LazyUser(String id) {
 829                         super(id);
 830                 }
 831
 832                 /**
 833                  * {@inheritDoc}
 834                  */
 835                 @Override
 836                 public Collection<String> getOpenIds() {
 837                         openIdMemoizer.get();
 838                         return super.getOpenIds();
 839                 }
 840
 841         }
 842
 843         /**
 844          * {@link ObjectCreator} implementation that can create {@link User}
 845          * objects. This specific implementation creates {@link LazyUser} instances.
 846          *
 847          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 848          */
 849         private class UserCreator implements ObjectCreator<User> {
 850
 851                 /**
 852                  * {@inheritDoc}
 853                  */
 854                 @Override
 855                 public User createObject(ResultSet resultSet) throws SQLException {
 856                         return new LazyUser(resultSet.getString("USERS.ID")).setName(resultSet.getString("USERS.NAME")).setPasswordHash(resultSet.getString("USERS.PASSWORD")).setLevel(resultSet.getInt("USERS.LEVEL"));
 857                 }
 858
 859         }
 860
 861 }