import java.util.Collection;
import java.util.HashSet;
import java.util.List;
+import java.util.concurrent.Callable;
+import net.pterodactylus.util.collection.Memoizer;
import net.pterodactylus.util.database.Database;
import net.pterodactylus.util.database.DatabaseException;
import net.pterodactylus.util.database.Field;
private final List<Track> loadedTracks = new ArrayList<Track>();
private Track track;
+ public Track get() {
+ return loadedTracks.isEmpty() ? null : loadedTracks.get(0);
+ }
+
public List<Track> all() {
return loadedTracks;
}
track = new DefaultTrack(trackId).name(resultSet.getString("TRACKS.NAME")).artists(new ArrayList<Artist>()).styles(new HashSet<Style>());
loadedTracks.add(track);
}
- Artist artist = new DefaultArtist(resultSet.getString("ARTISTS.ID")).name(resultSet.getString("ARTISTS.NAME"));
+ Artist artist = new LazyArtist(resultSet.getString("ARTISTS.ID")).name(resultSet.getString("ARTISTS.NAME"));
if (!track.artists().contains(artist)) {
track.artists().add(artist);
}
track.styles().add(style);
}
- public Track get() {
- return loadedTracks.isEmpty() ? null : loadedTracks.get(0);
- }
-
}
private class ArtistLoader implements ResultProcessor {
private final List<Artist> artists = new ArrayList<Artist>();
private Artist artist;
+ public Artist get() {
+ return artists.isEmpty() ? null : artists.get(0);
+ }
+
public List<Artist> all() {
return artists;
}
public void processResult(ResultSet resultSet) throws SQLException {
String artistId = resultSet.getString("ARTISTS.ID");
if ((artist == null) || (!artist.id().equals(artistId))) {
- artist = new DefaultArtist(artistId).name(resultSet.getString("ARTISTS.NAME")).groups(new HashSet<Group>());
+ artist = new LazyArtist(artistId).name(resultSet.getString("ARTISTS.NAME")).groups(new HashSet<Group>());
artists.add(artist);
}
}
+ private class LazyArtist extends DefaultArtist {
+
+ private final Memoizer<Void> tracksMemoizer = new Memoizer<Void>(new Callable<Void>() {
+ public Void call() throws DatabaseException {
+ if (!hasValue("tracks")) {
+ value("tracks", Collection.class).set(getTracksByArtist(id()));
+ }
+ return null;
+ }
+ });
+
+ public LazyArtist(String id) {
+ super(id);
+ }
+
+ public Collection<Track> tracks() {
+ tracksMemoizer.get();
+ return super.tracks();
+ }
+
+ }
+
}