X-Git-Url: https://git.pterodactylus.net/?a=blobdiff_plain;f=src%2Fmain%2Fjava%2Fnet%2Fpterodactylus%2Fdemoscenemusic%2Fdata%2FDataManager.java;h=f3252f0c8ece150440217e8efac84f2f1e671d06;hb=e3ac92367c0fde656598f388e9026f45c2868c4b;hp=928eebcf2223d0dfda7910443554792f8ef89494;hpb=f533deea6ecc3f1bd59ca8926c31dd7667ee572a;p=demoscenemusic.git

diff --git a/src/main/java/net/pterodactylus/demoscenemusic/data/DataManager.java b/src/main/java/net/pterodactylus/demoscenemusic/data/DataManager.java
index 928eebc..f3252f0 100644
--- a/src/main/java/net/pterodactylus/demoscenemusic/data/DataManager.java
+++ b/src/main/java/net/pterodactylus/demoscenemusic/data/DataManager.java
@@ -19,9 +19,7 @@ package net.pterodactylus.demoscenemusic.data;
 
 import java.sql.ResultSet;
 import java.sql.SQLException;
-import java.util.ArrayList;
 import java.util.Collection;
-import java.util.HashSet;
 import java.util.List;
 import java.util.concurrent.Callable;
 
@@ -31,176 +29,436 @@ import net.pterodactylus.util.database.DatabaseException;
 import net.pterodactylus.util.database.Field;
 import net.pterodactylus.util.database.Join;
 import net.pterodactylus.util.database.Join.JoinType;
+import net.pterodactylus.util.database.ObjectCreator;
 import net.pterodactylus.util.database.OrderField;
-import net.pterodactylus.util.database.OrderField.Order;
 import net.pterodactylus.util.database.Parameter.StringParameter;
 import net.pterodactylus.util.database.Query;
 import net.pterodactylus.util.database.Query.Type;
-import net.pterodactylus.util.database.ResultProcessor;
 import net.pterodactylus.util.database.ValueField;
 import net.pterodactylus.util.database.ValueFieldWhereClause;
 
 /**
- * TODO
+ * Interface between the database and the application.
  *
  * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
  */
 public class DataManager {
 
+	/** The artist object creator. */
+	@SuppressWarnings("synthetic-access")
+	private final ObjectCreator<Artist> artistCreator = new ArtistCreator();
+
+	/** The group object creator. */
+	@SuppressWarnings("synthetic-access")
+	private final ObjectCreator<Group> groupCreator = new GroupCreator();
+
+	/** The track object creator. */
+	@SuppressWarnings("synthetic-access")
+	private final ObjectCreator<Track> trackCreator = new TrackCreator();
+
+	/** The style object creator. */
+	@SuppressWarnings("synthetic-access")
+	private final ObjectCreator<Style> styleCreator = new StyleCreator();
+
+	/** The database. */
 	private final Database database;
 
+	/**
+	 * Creates a new data manager.
+	 *
+	 * @param database
+	 *            The database to operate on
+	 */
 	public DataManager(Database database) {
 		this.database = database;
 	}
 
+	/**
+	 * Returns all artists.
+	 *
+	 * @return All artists
+	 * @throws DatabaseException
+	 *             if a database error occurs
+	 */
 	public Collection<Artist> getAllArtists() throws DatabaseException {
 		Query query = new Query(Type.SELECT, "ARTISTS");
 		query.addField(new Field("ARTISTS.*"));
-		query.addField(new Field("GROUP_ARTISTS.*"));
-		query.addField(new Field("GROUPS.*"));
-		query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("ARTISTS.ID"), new Field("GROUP_ARTISTS.ARTIST")));
-		query.addJoin(new Join(JoinType.INNER, "GROUPS", new Field("GROUP_ARTISTS.GROUP_"), new Field("GROUPS.ID")));
-		query.addOrderField(new OrderField(new Field("ARTISTS.ID")));
-		ArtistLoader artistLoader = new ArtistLoader();
-		database.process(query, artistLoader);
-		return artistLoader.all();
+		return database.getMultiple(query, artistCreator);
 	}
 
+	/**
+	 * Returns the artist with the given ID.
+	 *
+	 * @param id
+	 *            The ID of the artist
+	 * @return The artist with the given ID, or {@code null} if there is no
+	 *         artist with the given ID
+	 * @throws DatabaseException
+	 *             if a database error occurs
+	 */
 	public Artist getArtistById(String id) throws DatabaseException {
 		Query query = new Query(Type.SELECT, "ARTISTS");
 		query.addField(new Field("ARTISTS.*"));
-		query.addField(new Field("GROUP_ARTISTS.*"));
-		query.addField(new Field("GROUPS.*"));
-		query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("ARTISTS.ID"), new Field("GROUP_ARTISTS.ARTIST")));
-		query.addJoin(new Join(JoinType.INNER, "GROUPS", new Field("GROUP_ARTISTS.GROUP_"), new Field("GROUPS.ID")));
 		query.addWhereClause(new ValueFieldWhereClause(new ValueField("ARTISTS.ID", new StringParameter(id))));
-		query.addOrderField(new OrderField(new Field("ARTISTS.ID")));
-		ArtistLoader artistLoader = new ArtistLoader();
-		database.process(query, artistLoader);
-		return artistLoader.get();
+		return database.getSingle(query, artistCreator);
 	}
 
-	public Track trackById(String id) throws DatabaseException {
+	/**
+	 * Returns all artists that belong to the group with the given ID.
+	 *
+	 * @param groupId
+	 *            The ID of the group
+	 * @return All artists belonging to the given group
+	 * @throws DatabaseException
+	 *             if a database error occurs
+	 */
+	public Collection<Artist> getArtistsByGroup(String groupId) throws DatabaseException {
+		Query query = new Query(Type.SELECT, "ARTISTS");
+		query.addField(new Field("ARTISTS.*"));
+		query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("ARTISTS.ID"), new Field("GROUP_ARTISTS.ARTIST")));
+		query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.GROUP_", new StringParameter(groupId))));
+		return database.getMultiple(query, artistCreator);
+	}
+
+	/**
+	 * Returns all artists involved in the track with the given ID.
+	 *
+	 * @param trackId
+	 *            The ID of the track
+	 * @return All artists involved in the track, in preferred order
+	 * @throws DatabaseException
+	 *             if a database error occurs
+	 */
+	public List<Artist> getArtistsByTrack(String trackId) throws DatabaseException {
+		Query query = new Query(Type.SELECT, "ARTISTS");
+		query.addField(new Field("ARTISTS.*"));
+		query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACK_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
+		query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.TRACK", new StringParameter(trackId))));
+		query.addOrderField(new OrderField(new Field("TRACK_ARTISTS.DISPLAY_ORDER")));
+		return database.getMultiple(query, artistCreator);
+	}
+
+	/**
+	 * Returns the track with the given ID.
+	 *
+	 * @param id
+	 *            The ID of the track
+	 * @return The track with the given ID, or {@code null} if there is no such
+	 *         track
+	 * @throws DatabaseException
+	 *             if a database error occurs
+	 */
+	public Track getTrackById(String id) throws DatabaseException {
 		Query query = new Query(Type.SELECT, "TRACKS");
 		query.addField(new Field("TRACKS.*"));
-		query.addField(new Field("TRACK_ARTISTS.*"));
-		query.addField(new Field("ARTISTS.*"));
-		query.addField(new Field("TRACK_STYLES.*"));
-		query.addField(new Field("STYLES.*"));
-		query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACKS.ID"), new Field("TRACK_ARTISTS.TRACK")));
-		query.addJoin(new Join(JoinType.INNER, "ARTISTS", new Field("TRACK_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
-		query.addJoin(new Join(JoinType.INNER, "TRACK_STYLES", new Field("TRACKS.ID"), new Field("TRACK_STYLES.TRACK")));
-		query.addJoin(new Join(JoinType.INNER, "STYLES", new Field("TRACK_STYLES.STYLE"), new Field("STYLES.ID")));
 		query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACKS.ID", new StringParameter(id))));
-		query.addOrderField(new OrderField(new Field("TRACKS.ID"), Order.ASCENDING));
-		query.addOrderField(new OrderField(new Field("TRACK_ARTISTS.DISPLAY_ORDER"), Order.ASCENDING));
-		TrackLoader trackLoader = new TrackLoader();
-		database.process(query, trackLoader);
-		return trackLoader.get();
+		return database.getSingle(query, trackCreator);
 	}
 
+	/**
+	 * Returns all tracks by the artist with the given ID.
+	 *
+	 * @param artistId
+	 *            The ID of the artist
+	 * @return All tracks by the given artist
+	 * @throws DatabaseException
+	 *             if a database error occurs
+	 */
 	public Collection<Track> getTracksByArtist(String artistId) throws DatabaseException {
 		Query query = new Query(Type.SELECT, "TRACKS");
 		query.addField(new Field("TRACKS.*"));
-		query.addField(new Field("TRACK_ARTISTS.*"));
-		query.addField(new Field("ARTISTS.*"));
-		query.addField(new Field("TRACK_STYLES.*"));
-		query.addField(new Field("STYLES.*"));
 		query.addJoin(new Join(JoinType.INNER, "TRACK_ARTISTS", new Field("TRACKS.ID"), new Field("TRACK_ARTISTS.TRACK")));
-		query.addJoin(new Join(JoinType.INNER, "ARTISTS", new Field("TRACK_ARTISTS.ARTIST"), new Field("ARTISTS.ID")));
-		query.addJoin(new Join(JoinType.INNER, "TRACK_STYLES", new Field("TRACKS.ID"), new Field("TRACK_STYLES.TRACK")));
-		query.addJoin(new Join(JoinType.INNER, "STYLES", new Field("TRACK_STYLES.STYLE"), new Field("STYLES.ID")));
-		query.addWhereClause(new ValueFieldWhereClause(new ValueField("ARTISTS.ID", new StringParameter(artistId))));
-		query.addOrderField(new OrderField(new Field("TRACKS.ID"), Order.ASCENDING));
-		query.addOrderField(new OrderField(new Field("TRACK_ARTISTS.DISPLAY_ORDER"), Order.ASCENDING));
-		TrackLoader trackLoader = new TrackLoader();
-		database.process(query, trackLoader);
-		return trackLoader.all();
+		query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_ARTISTS.ARTIST", new StringParameter(artistId))));
+		return database.getMultiple(query, trackCreator);
 	}
 
-	private class TrackLoader implements ResultProcessor {
+	/**
+	 * Returns all groups the artist with the given ID belongs to.
+	 *
+	 * @param artistId
+	 *            The ID of the artist
+	 * @return All groups the artist belongs to
+	 * @throws DatabaseException
+	 *             if a database error occurs
+	 */
+	public Collection<Group> getGroupsByArtist(String artistId) throws DatabaseException {
+		Query query = new Query(Type.SELECT, "GROUPS");
+		query.addField(new Field("GROUPS.*"));
+		query.addJoin(new Join(JoinType.INNER, "GROUP_ARTISTS", new Field("GROUPS.ID"), new Field("GROUP_ARTISTS.GROUP_")));
+		query.addWhereClause(new ValueFieldWhereClause(new ValueField("GROUP_ARTISTS.ARTIST", new StringParameter(artistId))));
+		return database.getMultiple(query, groupCreator);
+	}
 
-		private final List<Track> loadedTracks = new ArrayList<Track>();
-		private Track track;
+	/**
+	 * Returns all styles for the track with the given ID.
+	 *
+	 * @param trackId
+	 *            The ID of the track
+	 * @return All styles for the given track
+	 * @throws DatabaseException
+	 *             if a database error occurs
+	 */
+	public Collection<Style> getStylesByTrack(String trackId) throws DatabaseException {
+		Query query = new Query(Type.SELECT, "STYLES");
+		query.addField(new Field("STYLES.*"));
+		query.addJoin(new Join(JoinType.INNER, "TRACK_STYLES", new Field("STYLES.ID"), new Field("TRACK_STYLES.STYLE")));
+		query.addWhereClause(new ValueFieldWhereClause(new ValueField("TRACK_STYLES.TRACK", new StringParameter(trackId))));
+		return database.getMultiple(query, styleCreator);
+	}
+
+	/**
+	 * {@link Artist} implementation that retrieves some attributes (such as
+	 * {@link #getGroups()}, and {@link #getTracks()}) from the
+	 * {@link DataManager} on demand.
+	 *
+	 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+	 */
+	private class LazyArtist extends DefaultArtist {
 
-		public Track get() {
-			return loadedTracks.isEmpty() ? null : loadedTracks.get(0);
+		/** Memoizer for the tracks by this artist. */
+		private final Memoizer<Void> tracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
+			@Override
+			public Void call() throws DatabaseException {
+				if (!hasValue("tracks")) {
+					getValue("tracks", Collection.class).set(getTracksByArtist(getId()));
+				}
+				return null;
+			}
+		});
+
+		/** Memoizer for the groups of this artist. */
+		private final Memoizer<Void> groupsMemoizer = new Memoizer<Void>(new Callable<Void>() {
+
+			@Override
+			public Void call() throws Exception {
+				if (!hasValue("groups")) {
+					getValue("groups", Collection.class).set(getGroupsByArtist(getId()));
+				}
+				return null;
+			}
+
+		});
+
+		/**
+		 * Creates a new lazy artist.
+		 *
+		 * @param id
+		 *            The ID of the artist
+		 */
+		public LazyArtist(String id) {
+			super(id);
 		}
 
-		public List<Track> all() {
-			return loadedTracks;
+		//
+		// DEFAULTARTIST METHODS
+		//
+
+		/**
+		 * {@inheritDoc}
+		 */
+		@Override
+		public Collection<Group> getGroups() {
+			groupsMemoizer.get();
+			return super.getGroups();
 		}
 
 		/**
 		 * {@inheritDoc}
 		 */
-		public void processResult(ResultSet resultSet) throws SQLException {
-			String trackId = resultSet.getString("TRACKS.ID");
-			if ((track == null) || (!track.id().equals(trackId))) {
-				track = new DefaultTrack(trackId).name(resultSet.getString("TRACKS.NAME")).artists(new ArrayList<Artist>()).styles(new HashSet<Style>());
-				loadedTracks.add(track);
-			}
-			Artist artist = new LazyArtist(resultSet.getString("ARTISTS.ID")).name(resultSet.getString("ARTISTS.NAME"));
-			if (!track.artists().contains(artist)) {
-				track.artists().add(artist);
-			}
-			Style style = new DefaultStyle(resultSet.getString("STYLES.ID")).name(resultSet.getString("STYLES.NAME"));
-			track.styles().add(style);
+		@Override
+		public Collection<Track> getTracks() {
+			tracksMemoizer.get();
+			return super.getTracks();
 		}
 
 	}
 
-	private class ArtistLoader implements ResultProcessor {
+	/**
+	 * {@link ObjectCreator} implementation that can create {@link Artist}
+	 * objects. This specific class actually creates {@link LazyArtist}
+	 * instances.
+	 *
+	 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+	 */
+	private class ArtistCreator implements ObjectCreator<Artist> {
 
-		private final List<Artist> artists = new ArrayList<Artist>();
-		private Artist artist;
-
-		public Artist get() {
-			return artists.isEmpty() ? null : artists.get(0);
+		/**
+		 * {@inheritDoc}
+		 */
+		@Override
+		public Artist createObject(ResultSet resultSet) throws SQLException {
+			return new LazyArtist(resultSet.getString("ARTISTS.ID")).setName(resultSet.getString("ARTISTS.NAME"));
 		}
 
-		public List<Artist> all() {
-			return artists;
+	}
+
+	/**
+	 * {@link Group} implementation that retrieves some attributes (such as
+	 * {@link #getArtists()}) from the {@link DataManager} on demand.
+	 *
+	 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+	 */
+	private class LazyGroup extends DefaultGroup {
+
+		/** Memoizer for the artist. */
+		private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
+
+			@Override
+			public Void call() throws Exception {
+				if (!hasValue("artists")) {
+					getValue("artists", Collection.class).set(getArtistsByGroup(getId()));
+				}
+				return null;
+			}
+
+		});
+
+		/**
+		 * Creates a new lazy group.
+		 *
+		 * @param id
+		 *            The ID of the group
+		 */
+		public LazyGroup(String id) {
+			super(id);
 		}
 
 		//
-		// RESULTPROCESSOR METHODS
+		// DEFAULTGROUP METHODS
 		//
 
 		/**
 		 * {@inheritDoc}
 		 */
-		public void processResult(ResultSet resultSet) throws SQLException {
-			String artistId = resultSet.getString("ARTISTS.ID");
-			if ((artist == null) || (!artist.id().equals(artistId))) {
-				artist = new LazyArtist(artistId).name(resultSet.getString("ARTISTS.NAME")).groups(new HashSet<Group>());
-				artists.add(artist);
-			}
+		@Override
+		public Collection<Artist> getArtists() {
+			artistsMemoizer.get();
+			return super.getArtists();
+		}
+
+	}
+
+	/**
+	 * {@link ObjectCreator} implementation that can create {@link Group}
+	 * objects. This specific implementation creates {@link LazyGroup}
+	 * instances.
+	 *
+	 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+	 */
+	private class GroupCreator implements ObjectCreator<Group> {
 
-			Group group = new DefaultGroup(resultSet.getString("GROUPS.ID")).name(resultSet.getString("GROUPS.NAME")).url(resultSet.getString("GROUPS.URL"));
-			artist.groups().add(group);
+		/**
+		 * {@inheritDoc}
+		 */
+		@Override
+		public Group createObject(ResultSet resultSet) throws SQLException {
+			return new LazyGroup(resultSet.getString("GROUPS.ID")).setName(resultSet.getString("GROUPS.NAME")).setUrl(resultSet.getString("GROUPS.URL"));
 		}
 
 	}
 
-	private class LazyArtist extends DefaultArtist {
+	/**
+	 * {@link Track} implementation that retrieves some attributes (such as
+	 * {@link #getArtists()}, and {@link #getStyles()}) from the
+	 * {@link DataManager} on demand.
+	 *
+	 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+	 */
+	private class LazyTrack extends DefaultTrack {
 
-		private final Memoizer<Void> tracks = new Memoizer<Void>(new Callable<Void>() {
-			public Void call() throws DatabaseException {
-				if (!hasValue("tracks")) {
-					value("tracks", Collection.class).set(getTracksByArtist(id()));
+		/** Memoizer for the artists. */
+		private final Memoizer<Void> artistsMemoizer = new Memoizer<Void>(new Callable<Void>() {
+
+			@Override
+			public Void call() throws Exception {
+				if (!hasValue("artists")) {
+					getValue("artists", List.class).set(getArtistsByTrack(getId()));
 				}
 				return null;
 			}
+
 		});
 
-		public LazyArtist(String id) {
+		/** Memoizer for the styles. */
+		private final Memoizer<Void> stylesMemoizer = new Memoizer<Void>(new Callable<Void>() {
+
+			@Override
+			public Void call() throws Exception {
+				if (!hasValue("styles")) {
+					getValue("styles", Collection.class).set(getStylesByTrack(getId()));
+				}
+				return null;
+			}
+
+		});
+
+		/**
+		 * Creates a new track.
+		 *
+		 * @param id
+		 *            The ID of the track
+		 */
+		public LazyTrack(String id) {
 			super(id);
 		}
 
-		public Collection<Track> tracks() {
-			tracks.get();
-			return super.tracks();
+		//
+		// DEFAULTTRACK METHODS
+		//
+
+		/**
+		 * {@inheritDoc}
+		 */
+		@Override
+		public List<Artist> getArtists() {
+			artistsMemoizer.get();
+			return super.getArtists();
+		}
+
+		/**
+		 * {@inheritDoc}
+		 */
+		@Override
+		public Collection<Style> getStyles() {
+			stylesMemoizer.get();
+			return super.getStyles();
+		}
+
+	}
+
+	/**
+	 * {@link ObjectCreator} implementation that can create {@link Track}
+	 * objects. This specific implementation creates {@link LazyTrack}
+	 * instances.
+	 *
+	 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+	 */
+	private class TrackCreator implements ObjectCreator<Track> {
+
+		/**
+		 * {@inheritDoc}
+		 */
+		@Override
+		public Track createObject(ResultSet resultSet) throws SQLException {
+			return new LazyTrack(resultSet.getString("TRACKS.ID")).setName(resultSet.getString("TRACKS.NAME"));
+		}
+
+	}
+
+	/**
+	 * {@link ObjectCreator} implementation that can create {@link Style}
+	 * objects.
+	 *
+	 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
+	 */
+	private class StyleCreator implements ObjectCreator<Style> {
+
+		/**
+		 * {@inheritDoc}
+		 */
+		@Override
+		public Style createObject(ResultSet resultSet) throws SQLException {
+			return new DefaultStyle(resultSet.getString("STYLES.ID")).setName(resultSet.getString("STYLES.NAME"));
 		}
 
 	}