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.concurrent.Callable;
  28
  29 import net.pterodactylus.demoscenemusic.data.Track.Relationship;
  30 import net.pterodactylus.util.collection.Memoizer;
  31 import net.pterodactylus.util.database.Database;
  32 import net.pterodactylus.util.database.DatabaseException;
  33 import net.pterodactylus.util.database.Field;
  34 import net.pterodactylus.util.database.Join;
  35 import net.pterodactylus.util.database.Join.JoinType;
  36 import net.pterodactylus.util.database.ObjectCreator;
  37 import net.pterodactylus.util.database.ObjectCreator.StringCreator;
  38 import net.pterodactylus.util.database.OrderField;
  39 import net.pterodactylus.util.database.Parameter.StringParameter;
  40 import net.pterodactylus.util.database.Query;
  41 import net.pterodactylus.util.database.Query.Type;
  42 import net.pterodactylus.util.database.ResultProcessor;
  43 import net.pterodactylus.util.database.ValueField;
  44 import net.pterodactylus.util.database.ValueFieldWhereClause;
  45
  46 /**
  47  * Interface between the database and the application.
  48  *
  49  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  50  */
  51 public class DataManager {
  52
  53         /** The artist object creator. */
  54         @SuppressWarnings("synthetic-access")
  55         private final ObjectCreator<Artist> artistCreator = new ArtistCreator();
  56
  57         /** The group object creator. */
  58         @SuppressWarnings("synthetic-access")
  59         private final ObjectCreator<Group> groupCreator = new GroupCreator();
  60
  61         /** The track object creator. */
  62         @SuppressWarnings("synthetic-access")
  63         private final ObjectCreator<Track> trackCreator = new TrackCreator();
  64
  65         /** The style object creator. */
  66         @SuppressWarnings("synthetic-access")
  67         private final ObjectCreator<Style> styleCreator = new StyleCreator();
  68
  69         /** The {@link User} object creator. */
  70         @SuppressWarnings("synthetic-access")
  71         private final ObjectCreator<User> userCreator = new UserCreator();
  72
  73         /** The database. */
  74         private final Database database;
  75
  76         /**
  77          * Creates a new data manager.
  78          *
  79          * @param database
  80          *            The database to operate on
  81          */
  82         public DataManager(Database database) {
  83                 this.database = database;
  84         }
  85
  86         /**
  87          * Returns all artists.
  88          *
  89          * @return All artists
  90          * @throws DatabaseException
  91          *             if a database error occurs
  92          */
  93         public Collection<Artist> getAllArtists() throws DatabaseException {
  94                 Query query = new Query(Type.SELECT, "ARTISTS");
  95                 query.addField(new Field("ARTISTS.*"));
  96                 return database.getMultiple(query, artistCreator);
  97         }
  98
  99         /**
 100          * Returns the artist with the given ID.
 101          *
 102          * @param id
 103          *            The ID of the artist
 104          * @return The artist with the given ID, or {@code null} if there is no
 105          *         artist with the given ID
 106          * @throws DatabaseException
 107          *             if a database error occurs
 108          */
 109         public Artist getArtistById(String id) throws DatabaseException {
 110                 Query query = new Query(Type.SELECT, "ARTISTS");
 111                 query.addField(new Field("ARTISTS.*"));
 112                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ARTISTS.ID", new StringParameter(id))));
 113                 return database.getSingle(query, artistCreator);
 114         }
 115
 116         /**
 117          * Returns all artists that belong to the group with the given ID.
 118          *
 119          * @param groupId
 120          *            The ID of the group
 121          * @return All artists belonging to the given group
 122          * @throws DatabaseException
 123          *             if a database error occurs
 124          */
 125         public Collection<Artist> getArtistsByGroup(String groupId) throws DatabaseException {
 126                 Query query = new Query(Type.SELECT, "ARTISTS");
 127                 query.addField(new Field("ARTISTS.*"));
 128                 query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("ARTISTS.ID"), new Field("GROUP_ARTISTS.ARTIST")));
 129                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.GROUP_", new StringParameter(groupId))));
 130                 return database.getMultiple(query, artistCreator);
 131         }
 132
 133         /**
 134          * Returns all artists involved in the track with the given ID.
 135          *
 136          * @param trackId
 137          *            The ID of the track
 138          * @return All artists involved in the track, in preferred order
 139          * @throws DatabaseException
 140          *             if a database error occurs
 141          */
 142         public List<Artist> getArtistsByTrack(String trackId) throws DatabaseException {
 143                 Query query = new Query(Type.SELECT, "ARTISTS");
 144                 query.addField(new Field("ARTISTS.*"));
 145                 query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACK_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
 146                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(trackId))));
 147                 query.addOrderField(new OrderField(new Field("TRACK_ARTISTS.DISPLAY_ORDER")));
 148                 return database.getMultiple(query, artistCreator);
 149         }
 150
 151         /**
 152          * Returns all remix artists involved in the track with the given ID.
 153          *
 154          * @param trackId
 155          *            The ID of the track
 156          * @return All remix artists involved in the track, in preferred order
 157          * @throws DatabaseException
 158          *             if a database error occurs
 159          */
 160         public List<Artist> getRemixArtistsByTrack(String trackId) throws DatabaseException {
 161                 Query query = new Query(Type.SELECT, "ARTISTS");
 162                 query.addField(new Field("ARTISTS.*"));
 163                 query.addJoin(new Join(JoinType.INNER, "TRACK_REMIX_ARTISTS", new Field("TRACK_REMIX_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
 164                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_REMIX_ARTISTS.TRACK", new StringParameter(trackId))));
 165                 query.addOrderField(new OrderField(new Field("TRACK_REMIX_ARTISTS.DISPLAY_ORDER")));
 166                 return database.getMultiple(query, artistCreator);
 167         }
 168
 169         /**
 170          * Returns all related tracks for the track with the given ID.
 171          *
 172          * @param trackId
 173          *            The ID of the tracks
 174          * @return A mapping from relationship to all tracks that match the relation
 175          * @throws DatabaseException
 176          *             if a database error occurs
 177          */
 178         public Map<Relationship, Collection<Track>> getRelatedTracksByTrack(String trackId) throws DatabaseException {
 179                 Query query = new Query(Type.SELECT, "TRACKS");
 180                 query.addField(new Field("TRACKS.*"));
 181                 query.addField(new Field("TRACK_RELATIONS.*"));
 182                 query.addJoin(new Join(JoinType.INNER, "TRACK_RELATIONS", new Field("TRACK_RELATIONS.TRACK"), new Field("TRACK_RELATIONS.RELATED_TRACK")));
 183                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_RELATIONS.TRACK", new StringParameter(trackId))));
 184                 final Map<Relationship, Collection<Track>> relatedTracks = new EnumMap<Relationship, Collection<Track>>(Relationship.class);
 185                 database.process(query, new ResultProcessor() {
 186
 187                         @Override
 188                         @SuppressWarnings("synthetic-access")
 189                         public void processResult(ResultSet resultSet) throws SQLException {
 190                                 Track track = trackCreator.createObject(resultSet);
 191                                 Relationship relationship = Relationship.valueOf(resultSet.getString("TRACK_RELATIONS.RELATIONSHIP"));
 192                                 if (!relatedTracks.containsKey(relationship)) {
 193                                         relatedTracks.put(relationship, new HashSet<Track>());
 194                                 }
 195                                 relatedTracks.get(relationship).add(track);
 196                         }
 197                 });
 198                 return relatedTracks;
 199         }
 200
 201         /**
 202          * Returns the track with the given ID.
 203          *
 204          * @param id
 205          *            The ID of the track
 206          * @return The track with the given ID, or {@code null} if there is no such
 207          *         track
 208          * @throws DatabaseException
 209          *             if a database error occurs
 210          */
 211         public Track getTrackById(String id) throws DatabaseException {
 212                 Query query = new Query(Type.SELECT, "TRACKS");
 213                 query.addField(new Field("TRACKS.*"));
 214                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACKS.ID", new StringParameter(id))));
 215                 return database.getSingle(query, trackCreator);
 216         }
 217
 218         /**
 219          * Returns all tracks by the artist with the given ID.
 220          *
 221          * @param artistId
 222          *            The ID of the artist
 223          * @return All tracks by the given artist
 224          * @throws DatabaseException
 225          *             if a database error occurs
 226          */
 227         public Collection<Track> getTracksByArtist(String artistId) throws DatabaseException {
 228                 Query query = new Query(Type.SELECT, "TRACKS");
 229                 query.addField(new Field("TRACKS.*"));
 230                 query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACKS.ID"), new Field("TRACK_ARTISTS.TRACK")));
 231                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.ARTIST", new StringParameter(artistId))));
 232                 return database.getMultiple(query, trackCreator);
 233         }
 234
 235         /**
 236          * Returns all groups the artist with the given ID belongs to.
 237          *
 238          * @param artistId
 239          *            The ID of the artist
 240          * @return All groups the artist belongs to
 241          * @throws DatabaseException
 242          *             if a database error occurs
 243          */
 244         public Collection<Group> getGroupsByArtist(String artistId) throws DatabaseException {
 245                 Query query = new Query(Type.SELECT, "GROUPS");
 246                 query.addField(new Field("GROUPS.*"));
 247                 query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("GROUPS.ID"), new Field("GROUP_ARTISTS.GROUP_")));
 248                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.ARTIST", new StringParameter(artistId))));
 249                 return database.getMultiple(query, groupCreator);
 250         }
 251
 252         /**
 253          * Returns all styles for the track with the given ID.
 254          *
 255          * @param trackId
 256          *            The ID of the track
 257          * @return All styles for the given track
 258          * @throws DatabaseException
 259          *             if a database error occurs
 260          */
 261         public Collection<Style> getStylesByTrack(String trackId) throws DatabaseException {
 262                 Query query = new Query(Type.SELECT, "STYLES");
 263                 query.addField(new Field("STYLES.*"));
 264                 query.addJoin(new Join(JoinType.INNER, "TRACK_STYLES", new Field("STYLES.ID"), new Field("TRACK_STYLES.STYLE")));
 265                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_STYLES.TRACK", new StringParameter(trackId))));
 266                 return database.getMultiple(query, styleCreator);
 267         }
 268
 269         /**
 270          * Returns the user connected with the given OpenID.
 271          *
 272          * @param openId
 273          *            The OpenID to find the user for
 274          * @return The user connected with the given OpenID, or {@code null} if
 275          *         there is no such user
 276          * @throws DatabaseException
 277          *             if a database error occurs
 278          */
 279         public User getUserByOpenId(String openId) throws DatabaseException {
 280                 Query query = new Query(Type.SELECT, "USERS");
 281                 query.addField(new Field("USERS.*"));
 282                 query.addJoin(new Join(JoinType.INNER, "USER_OPENIDS", new Field("USER_OPENIDS.USER"), new Field("USERS.ID")));
 283                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USER_OPENIDS.OPENID", new StringParameter(openId))));
 284                 return database.getSingle(query, userCreator);
 285         }
 286
 287         /**
 288          * Returns all OpenIDs connected with the user with the given ID.
 289          *
 290          * @param userId
 291          *            The ID of the user
 292          * @return All OpenIDs connected with the given user
 293          * @throws DatabaseException
 294          *             if a database error occurs
 295          */
 296         public Collection<String> getOpenIdsByUser(String userId) throws DatabaseException {
 297                 Query query = new Query(Type.SELECT, "USER_OPENIDS");
 298                 query.addField(new Field("USER_OPENIDS.*"));
 299                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("USER_OPENIDS.USER", new StringParameter(userId))));
 300                 return database.getMultiple(query, new StringCreator("USER_OPENIDS.OPENID"));
 301         }
 302
 303         /**
 304          * {@link Artist} implementation that retrieves some attributes (such as
 305          * {@link #getGroups()}, and {@link #getTracks()}) from the
 306          * {@link DataManager} on demand.
 307          *
 308          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 309          */
 310         private class LazyArtist extends DefaultArtist {
 311
 312                 /** Memoizer for the tracks by this artist. */
 313                 private final Memoizer<Void> tracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
 314                         @Override
 315                         public Void call() throws DatabaseException {
 316                                 if (!hasValue("tracks")) {
 317                                         getValue("tracks", Collection.class).set(getTracksByArtist(getId()));
 318                                 }
 319                                 return null;
 320                         }
 321                 });
 322
 323                 /** Memoizer for the groups of this artist. */
 324                 private final Memoizer<Void> groupsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 325
 326                         @Override
 327                         public Void call() throws Exception {
 328                                 if (!hasValue("groups")) {
 329                                         getValue("groups", Collection.class).set(getGroupsByArtist(getId()));
 330                                 }
 331                                 return null;
 332                         }
 333
 334                 });
 335
 336                 /**
 337                  * Creates a new lazy artist.
 338                  *
 339                  * @param id
 340                  *            The ID of the artist
 341                  */
 342                 public LazyArtist(String id) {
 343                         super(id);
 344                 }
 345
 346                 //
 347                 // DEFAULTARTIST METHODS
 348                 //
 349
 350                 /**
 351                  * {@inheritDoc}
 352                  */
 353                 @Override
 354                 public Collection<Group> getGroups() {
 355                         groupsMemoizer.get();
 356                         return super.getGroups();
 357                 }
 358
 359                 /**
 360                  * {@inheritDoc}
 361                  */
 362                 @Override
 363                 public Collection<Track> getTracks() {
 364                         tracksMemoizer.get();
 365                         return super.getTracks();
 366                 }
 367
 368         }
 369
 370         /**
 371          * {@link ObjectCreator} implementation that can create {@link Artist}
 372          * objects. This specific class actually creates {@link LazyArtist}
 373          * instances.
 374          *
 375          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 376          */
 377         private class ArtistCreator implements ObjectCreator<Artist> {
 378
 379                 /**
 380                  * {@inheritDoc}
 381                  */
 382                 @Override
 383                 public Artist createObject(ResultSet resultSet) throws SQLException {
 384                         return new LazyArtist(resultSet.getString("ARTISTS.ID")).setName(resultSet.getString("ARTISTS.NAME"));
 385                 }
 386
 387         }
 388
 389         /**
 390          * {@link Group} implementation that retrieves some attributes (such as
 391          * {@link #getArtists()}) from the {@link DataManager} on demand.
 392          *
 393          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 394          */
 395         private class LazyGroup extends DefaultGroup {
 396
 397                 /** Memoizer for the artist. */
 398                 private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 399
 400                         @Override
 401                         public Void call() throws Exception {
 402                                 if (!hasValue("artists")) {
 403                                         getValue("artists", Collection.class).set(getArtistsByGroup(getId()));
 404                                 }
 405                                 return null;
 406                         }
 407
 408                 });
 409
 410                 /**
 411                  * Creates a new lazy group.
 412                  *
 413                  * @param id
 414                  *            The ID of the group
 415                  */
 416                 public LazyGroup(String id) {
 417                         super(id);
 418                 }
 419
 420                 //
 421                 // DEFAULTGROUP METHODS
 422                 //
 423
 424                 /**
 425                  * {@inheritDoc}
 426                  */
 427                 @Override
 428                 public Collection<Artist> getArtists() {
 429                         artistsMemoizer.get();
 430                         return super.getArtists();
 431                 }
 432
 433         }
 434
 435         /**
 436          * {@link ObjectCreator} implementation that can create {@link Group}
 437          * objects. This specific implementation creates {@link LazyGroup}
 438          * instances.
 439          *
 440          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 441          */
 442         private class GroupCreator implements ObjectCreator<Group> {
 443
 444                 /**
 445                  * {@inheritDoc}
 446                  */
 447                 @Override
 448                 public Group createObject(ResultSet resultSet) throws SQLException {
 449                         return new LazyGroup(resultSet.getString("GROUPS.ID")).setName(resultSet.getString("GROUPS.NAME")).setUrl(resultSet.getString("GROUPS.URL"));
 450                 }
 451
 452         }
 453
 454         /**
 455          * {@link Track} implementation that retrieves some attributes (such as
 456          * {@link #getArtists()}, and {@link #getStyles()}) from the
 457          * {@link DataManager} on demand.
 458          *
 459          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 460          */
 461         private class LazyTrack extends DefaultTrack {
 462
 463                 /** Memoizer for the artists. */
 464                 private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 465
 466                         @Override
 467                         public Void call() throws Exception {
 468                                 if (!hasValue("artists")) {
 469                                         getValue("artists", List.class).set(getArtistsByTrack(getId()));
 470                                 }
 471                                 return null;
 472                         }
 473
 474                 });
 475
 476                 /** Memoizer for the styles. */
 477                 private final Memoizer<Void> stylesMemoizer = new Memoizer<Void>(new Callable<Void>() {
 478
 479                         @Override
 480                         public Void call() throws Exception {
 481                                 if (!hasValue("styles")) {
 482                                         getValue("styles", Collection.class).set(getStylesByTrack(getId()));
 483                                 }
 484                                 return null;
 485                         }
 486
 487                 });
 488
 489                 /** Memoizer for the remix artists. */
 490                 private final Memoizer<Void> remixArtistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 491
 492                         @Override
 493                         public Void call() throws Exception {
 494                                 if (!hasValue("remixArtists")) {
 495                                         getValue("remixArtists", List.class).set(getRemixArtistsByTrack(getId()));
 496                                 }
 497                                 return null;
 498                         }
 499
 500                 });
 501
 502                 /** Memoizer for the related tracks. */
 503                 private final Memoizer<Void> relatedTracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
 504
 505                         @Override
 506                         public Void call() throws Exception {
 507                                 if (!hasValue("relatedTracks")) {
 508                                         getValue("relatedTracks", Map.class).set(getRelatedTracksByTrack(getId()));
 509                                 }
 510                                 return null;
 511                         }
 512                 });
 513
 514                 /**
 515                  * Creates a new track.
 516                  *
 517                  * @param id
 518                  *            The ID of the track
 519                  */
 520                 public LazyTrack(String id) {
 521                         super(id);
 522                 }
 523
 524                 //
 525                 // DEFAULTTRACK METHODS
 526                 //
 527
 528                 /**
 529                  * {@inheritDoc}
 530                  */
 531                 @Override
 532                 public List<Artist> getArtists() {
 533                         artistsMemoizer.get();
 534                         return super.getArtists();
 535                 }
 536
 537                 /**
 538                  * {@inheritDoc}
 539                  */
 540                 @Override
 541                 public Collection<Style> getStyles() {
 542                         stylesMemoizer.get();
 543                         return super.getStyles();
 544                 }
 545
 546                 /**
 547                  * {@inheritDoc}
 548                  */
 549                 @Override
 550                 public List<Artist> getRemixArtists() {
 551                         remixArtistsMemoizer.get();
 552                         return super.getRemixArtists();
 553                 }
 554
 555                 /**
 556                  * {@inheritDoc}
 557                  */
 558                 @Override
 559                 public Map<Relationship, Collection<Track>> getRelatedTracks() {
 560                         relatedTracksMemoizer.get();
 561                         return super.getRelatedTracks();
 562                 }
 563
 564         }
 565
 566         /**
 567          * {@link ObjectCreator} implementation that can create {@link Track}
 568          * objects. This specific implementation creates {@link LazyTrack}
 569          * instances.
 570          *
 571          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 572          */
 573         private class TrackCreator implements ObjectCreator<Track> {
 574
 575                 /**
 576                  * {@inheritDoc}
 577                  */
 578                 @Override
 579                 public Track createObject(ResultSet resultSet) throws SQLException {
 580                         return new LazyTrack(resultSet.getString("TRACKS.ID")).setName(resultSet.getString("TRACKS.NAME")).setRemix(resultSet.getString("TRACKS.REMIX"));
 581                 }
 582
 583         }
 584
 585         /**
 586          * {@link ObjectCreator} implementation that can create {@link Style}
 587          * objects.
 588          *
 589          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 590          */
 591         private class StyleCreator implements ObjectCreator<Style> {
 592
 593                 /**
 594                  * {@inheritDoc}
 595                  */
 596                 @Override
 597                 public Style createObject(ResultSet resultSet) throws SQLException {
 598                         return new DefaultStyle(resultSet.getString("STYLES.ID")).setName(resultSet.getString("STYLES.NAME"));
 599                 }
 600
 601         }
 602
 603         /**
 604          * {@link User} implementation that retrieves some attributes (such as
 605          * {@link #getOpenIds()}) from the {@link DataManager} on demand.
 606          *
 607          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 608          */
 609         private class LazyUser extends DefaultUser {
 610
 611                 /** Memoizer for a user’s OpenIDs. */
 612                 private final Memoizer<Void> openIdMemoizer = new Memoizer<Void>(new Callable<Void>() {
 613
 614                         @Override
 615                         public Void call() throws Exception {
 616                                 if (!hasValue("openIds")) {
 617                                         getValue("openIds", Collection.class).set(getOpenIdsByUser(getId()));
 618                                 }
 619                                 return null;
 620                         }
 621                 });
 622
 623                 /**
 624                  * Creates a new user.
 625                  *
 626                  * @param id
 627                  *            The ID of the user
 628                  */
 629                 public LazyUser(String id) {
 630                         super(id);
 631                 }
 632
 633                 /**
 634                  * {@inheritDoc}
 635                  */
 636                 @Override
 637                 public Collection<String> getOpenIds() {
 638                         openIdMemoizer.get();
 639                         return super.getOpenIds();
 640                 }
 641
 642         }
 643
 644         /**
 645          * {@link ObjectCreator} implementation that can create {@link User}
 646          * objects. This specific implementation creates {@link LazyUser} instances.
 647          *
 648          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 649          */
 650         private class UserCreator implements ObjectCreator<User> {
 651
 652                 /**
 653                  * {@inheritDoc}
 654                  */
 655                 @Override
 656                 public User createObject(ResultSet resultSet) throws SQLException {
 657                         return new LazyUser(resultSet.getString("USERS.ID")).setName(resultSet.getString("USERS.NAME"));
 658                 }
 659
 660         }
 661
 662 }