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.List;
  24 import java.util.concurrent.Callable;
  25
  26 import net.pterodactylus.util.collection.Memoizer;
  27 import net.pterodactylus.util.database.Database;
  28 import net.pterodactylus.util.database.DatabaseException;
  29 import net.pterodactylus.util.database.Field;
  30 import net.pterodactylus.util.database.Join;
  31 import net.pterodactylus.util.database.Join.JoinType;
  32 import net.pterodactylus.util.database.ObjectCreator;
  33 import net.pterodactylus.util.database.OrderField;
  34 import net.pterodactylus.util.database.Parameter.StringParameter;
  35 import net.pterodactylus.util.database.Query;
  36 import net.pterodactylus.util.database.Query.Type;
  37 import net.pterodactylus.util.database.ValueField;
  38 import net.pterodactylus.util.database.ValueFieldWhereClause;
  39
  40 /**
  41  * Interface between the database and the application.
  42  *
  43  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  44  */
  45 public class DataManager {
  46
  47         /** The artist object creator. */
  48         @SuppressWarnings("synthetic-access")
  49         private final ObjectCreator<Artist> artistCreator = new ArtistCreator();
  50
  51         /** The group object creator. */
  52         @SuppressWarnings("synthetic-access")
  53         private final ObjectCreator<Group> groupCreator = new GroupCreator();
  54
  55         /** The track object creator. */
  56         @SuppressWarnings("synthetic-access")
  57         private final ObjectCreator<Track> trackCreator = new TrackCreator();
  58
  59         /** The style object creator. */
  60         @SuppressWarnings("synthetic-access")
  61         private final ObjectCreator<Style> styleCreator = new StyleCreator();
  62
  63         /** The database. */
  64         private final Database database;
  65
  66         /**
  67          * Creates a new data manager.
  68          *
  69          * @param database
  70          *            The database to operate on
  71          */
  72         public DataManager(Database database) {
  73                 this.database = database;
  74         }
  75
  76         /**
  77          * Returns all artists.
  78          *
  79          * @return All artists
  80          * @throws DatabaseException
  81          *             if a database error occurs
  82          */
  83         public Collection<Artist> getAllArtists() throws DatabaseException {
  84                 Query query = new Query(Type.SELECT, "ARTISTS");
  85                 query.addField(new Field("ARTISTS.*"));
  86                 return database.getMultiple(query, artistCreator);
  87         }
  88
  89         /**
  90          * Returns the artist with the given ID.
  91          *
  92          * @param id
  93          *            The ID of the artist
  94          * @return The artist with the given ID, or {@code null} if there is no
  95          *         artist with the given ID
  96          * @throws DatabaseException
  97          *             if a database error occurs
  98          */
  99         public Artist getArtistById(String id) throws DatabaseException {
 100                 Query query = new Query(Type.SELECT, "ARTISTS");
 101                 query.addField(new Field("ARTISTS.*"));
 102                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("ARTISTS.ID", new StringParameter(id))));
 103                 return database.getSingle(query, artistCreator);
 104         }
 105
 106         /**
 107          * Returns all artists that belong to the group with the given ID.
 108          *
 109          * @param groupId
 110          *            The ID of the group
 111          * @return All artists belonging to the given group
 112          * @throws DatabaseException
 113          *             if a database error occurs
 114          */
 115         public Collection<Artist> getArtistsByGroup(String groupId) throws DatabaseException {
 116                 Query query = new Query(Type.SELECT, "ARTISTS");
 117                 query.addField(new Field("ARTISTS.*"));
 118                 query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("ARTISTS.ID"), new Field("GROUP_ARTISTS.ARTIST")));
 119                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.GROUP_", new StringParameter(groupId))));
 120                 return database.getMultiple(query, artistCreator);
 121         }
 122
 123         /**
 124          * Returns all artists involved in the track with the given ID.
 125          *
 126          * @param trackId
 127          *            The ID of the track
 128          * @return All artists involved in the track, in preferred order
 129          * @throws DatabaseException
 130          *             if a database error occurs
 131          */
 132         public List<Artist> getArtistsByTrack(String trackId) throws DatabaseException {
 133                 Query query = new Query(Type.SELECT, "ARTISTS");
 134                 query.addField(new Field("ARTISTS.*"));
 135                 query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACK_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
 136                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(trackId))));
 137                 query.addOrderField(new OrderField(new Field("TRACK_ARTISTS.DISPLAY_ORDER")));
 138                 return database.getMultiple(query, artistCreator);
 139         }
 140
 141         /**
 142          * Returns the track with the given ID.
 143          *
 144          * @param id
 145          *            The ID of the track
 146          * @return The track with the given ID, or {@code null} if there is no such
 147          *         track
 148          * @throws DatabaseException
 149          *             if a database error occurs
 150          */
 151         public Track getTrackById(String id) throws DatabaseException {
 152                 Query query = new Query(Type.SELECT, "TRACKS");
 153                 query.addField(new Field("TRACKS.*"));
 154                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACKS.ID", new StringParameter(id))));
 155                 return database.getSingle(query, trackCreator);
 156         }
 157
 158         /**
 159          * Returns all tracks by the artist with the given ID.
 160          *
 161          * @param artistId
 162          *            The ID of the artist
 163          * @return All tracks by the given artist
 164          * @throws DatabaseException
 165          *             if a database error occurs
 166          */
 167         public Collection<Track> getTracksByArtist(String artistId) throws DatabaseException {
 168                 Query query = new Query(Type.SELECT, "TRACKS");
 169                 query.addField(new Field("TRACKS.*"));
 170                 query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACKS.ID"), new Field("TRACK_ARTISTS.TRACK")));
 171                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.ARTIST", new StringParameter(artistId))));
 172                 return database.getMultiple(query, trackCreator);
 173         }
 174
 175         /**
 176          * Returns all groups the artist with the given ID belongs to.
 177          *
 178          * @param artistId
 179          *            The ID of the artist
 180          * @return All groups the artist belongs to
 181          * @throws DatabaseException
 182          *             if a database error occurs
 183          */
 184         public Collection<Group> getGroupsByArtist(String artistId) throws DatabaseException {
 185                 Query query = new Query(Type.SELECT, "GROUPS");
 186                 query.addField(new Field("GROUPS.*"));
 187                 query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("GROUPS.ID"), new Field("GROUP_ARTISTS.GROUP_")));
 188                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.ARTIST", new StringParameter(artistId))));
 189                 return database.getMultiple(query, groupCreator);
 190         }
 191
 192         /**
 193          * Returns all styles for the track with the given ID.
 194          *
 195          * @param trackId
 196          *            The ID of the track
 197          * @return All styles for the given track
 198          * @throws DatabaseException
 199          *             if a database error occurs
 200          */
 201         public Collection<Style> getStylesByTrack(String trackId) throws DatabaseException {
 202                 Query query = new Query(Type.SELECT, "STYLES");
 203                 query.addField(new Field("STYLES.*"));
 204                 query.addJoin(new Join(JoinType.INNER, "TRACK_STYLES", new Field("STYLES.ID"), new Field("TRACK_STYLES.STYLE")));
 205                 query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_STYLES.TRACK", new StringParameter(trackId))));
 206                 return database.getMultiple(query, styleCreator);
 207         }
 208
 209         /**
 210          * {@link Artist} implementation that retrieves some attributes (such as
 211          * {@link #getGroups()}, and {@link #getTracks()}) from the
 212          * {@link DataManager} on demand.
 213          *
 214          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 215          */
 216         private class LazyArtist extends DefaultArtist {
 217
 218                 /** Memoizer for the tracks by this artist. */
 219                 private final Memoizer<Void> tracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
 220                         @Override
 221                         public Void call() throws DatabaseException {
 222                                 if (!hasValue("tracks")) {
 223                                         getValue("tracks", Collection.class).set(getTracksByArtist(getId()));
 224                                 }
 225                                 return null;
 226                         }
 227                 });
 228
 229                 /** Memoizer for the groups of this artist. */
 230                 private final Memoizer<Void> groupsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 231
 232                         @Override
 233                         public Void call() throws Exception {
 234                                 if (!hasValue("groups")) {
 235                                         getValue("groups", Collection.class).set(getGroupsByArtist(getId()));
 236                                 }
 237                                 return null;
 238                         }
 239
 240                 });
 241
 242                 /**
 243                  * Creates a new lazy artist.
 244                  *
 245                  * @param id
 246                  *            The ID of the artist
 247                  */
 248                 public LazyArtist(String id) {
 249                         super(id);
 250                 }
 251
 252                 //
 253                 // DEFAULTARTIST METHODS
 254                 //
 255
 256                 /**
 257                  * {@inheritDoc}
 258                  */
 259                 @Override
 260                 public Collection<Group> getGroups() {
 261                         groupsMemoizer.get();
 262                         return super.getGroups();
 263                 }
 264
 265                 /**
 266                  * {@inheritDoc}
 267                  */
 268                 @Override
 269                 public Collection<Track> getTracks() {
 270                         tracksMemoizer.get();
 271                         return super.getTracks();
 272                 }
 273
 274         }
 275
 276         /**
 277          * {@link ObjectCreator} implementation that can create {@link Artist}
 278          * objects. This specific class actually creates {@link LazyArtist}
 279          * instances.
 280          *
 281          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 282          */
 283         private class ArtistCreator implements ObjectCreator<Artist> {
 284
 285                 /**
 286                  * {@inheritDoc}
 287                  */
 288                 @Override
 289                 public Artist createObject(ResultSet resultSet) throws SQLException {
 290                         return new LazyArtist(resultSet.getString("ARTISTS.ID")).setName(resultSet.getString("ARTISTS.NAME"));
 291                 }
 292
 293         }
 294
 295         /**
 296          * {@link Group} implementation that retrieves some attributes (such as
 297          * {@link #getArtists()}) from the {@link DataManager} on demand.
 298          *
 299          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 300          */
 301         private class LazyGroup extends DefaultGroup {
 302
 303                 /** Memoizer for the artist. */
 304                 private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 305
 306                         @Override
 307                         public Void call() throws Exception {
 308                                 if (!hasValue("artists")) {
 309                                         getValue("artists", Collection.class).set(getArtistsByGroup(getId()));
 310                                 }
 311                                 return null;
 312                         }
 313
 314                 });
 315
 316                 /**
 317                  * Creates a new lazy group.
 318                  *
 319                  * @param id
 320                  *            The ID of the group
 321                  */
 322                 public LazyGroup(String id) {
 323                         super(id);
 324                 }
 325
 326                 //
 327                 // DEFAULTGROUP METHODS
 328                 //
 329
 330                 /**
 331                  * {@inheritDoc}
 332                  */
 333                 @Override
 334                 public Collection<Artist> getArtists() {
 335                         artistsMemoizer.get();
 336                         return super.getArtists();
 337                 }
 338
 339         }
 340
 341         /**
 342          * {@link ObjectCreator} implementation that can create {@link Group}
 343          * objects. This specific implementation creates {@link LazyGroup}
 344          * instances.
 345          *
 346          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 347          */
 348         private class GroupCreator implements ObjectCreator<Group> {
 349
 350                 /**
 351                  * {@inheritDoc}
 352                  */
 353                 @Override
 354                 public Group createObject(ResultSet resultSet) throws SQLException {
 355                         return new LazyGroup(resultSet.getString("GROUPS.ID")).setName(resultSet.getString("GROUPS.NAME")).setUrl(resultSet.getString("GROUPS.URL"));
 356                 }
 357
 358         }
 359
 360         /**
 361          * {@link Track} implementation that retrieves some attributes (such as
 362          * {@link #getArtists()}, and {@link #getStyles()}) from the
 363          * {@link DataManager} on demand.
 364          *
 365          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 366          */
 367         private class LazyTrack extends DefaultTrack {
 368
 369                 /** Memoizer for the artists. */
 370                 private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
 371
 372                         @Override
 373                         public Void call() throws Exception {
 374                                 if (!hasValue("artists")) {
 375                                         getValue("artists", List.class).set(getArtistsByTrack(getId()));
 376                                 }
 377                                 return null;
 378                         }
 379
 380                 });
 381
 382                 /** Memoizer for the styles. */
 383                 private final Memoizer<Void> stylesMemoizer = new Memoizer<Void>(new Callable<Void>() {
 384
 385                         @Override
 386                         public Void call() throws Exception {
 387                                 if (!hasValue("styles")) {
 388                                         getValue("styles", Collection.class).set(getStylesByTrack(getId()));
 389                                 }
 390                                 return null;
 391                         }
 392
 393                 });
 394
 395                 /**
 396                  * Creates a new track.
 397                  *
 398                  * @param id
 399                  *            The ID of the track
 400                  */
 401                 public LazyTrack(String id) {
 402                         super(id);
 403                 }
 404
 405                 //
 406                 // DEFAULTTRACK METHODS
 407                 //
 408
 409                 /**
 410                  * {@inheritDoc}
 411                  */
 412                 @Override
 413                 public List<Artist> getArtists() {
 414                         artistsMemoizer.get();
 415                         return super.getArtists();
 416                 }
 417
 418                 /**
 419                  * {@inheritDoc}
 420                  */
 421                 @Override
 422                 public Collection<Style> getStyles() {
 423                         stylesMemoizer.get();
 424                         return super.getStyles();
 425                 }
 426
 427         }
 428
 429         /**
 430          * {@link ObjectCreator} implementation that can create {@link Track}
 431          * objects. This specific implementation creates {@link LazyTrack}
 432          * instances.
 433          *
 434          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 435          */
 436         private class TrackCreator implements ObjectCreator<Track> {
 437
 438                 /**
 439                  * {@inheritDoc}
 440                  */
 441                 @Override
 442                 public Track createObject(ResultSet resultSet) throws SQLException {
 443                         return new LazyTrack(resultSet.getString("TRACKS.ID")).setName(resultSet.getString("TRACKS.NAME"));
 444                 }
 445
 446         }
 447
 448         /**
 449          * {@link ObjectCreator} implementation that can create {@link Style}
 450          * objects.
 451          *
 452          * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
 453          */
 454         private class StyleCreator implements ObjectCreator<Style> {
 455
 456                 /**
 457                  * {@inheritDoc}
 458                  */
 459                 @Override
 460                 public Style createObject(ResultSet resultSet) throws SQLException {
 461                         return new DefaultStyle(resultSet.getString("STYLES.ID")).setName(resultSet.getString("STYLES.NAME"));
 462                 }
 463
 464         }
 465
 466 }