Library updates now attempt to remove songs that weren't indexed during the update.

src/main/java/musicplayer/db/HibernateDatabase.java

@@ -104,6 +104,21 @@ public class HibernateDatabase implements IDatabase{
         }
     }
 
+    /**
+     * Delete all songs that don't have ids in the given list.
+     * @param ids List of songs to keep.
+     */
+    public void batchDeleteNot(Long[] ids){
+        try(Session session = getSession()) {
+            session.beginTransaction();
+            @SuppressWarnings("unchecked")
+            List<Song> songs = (List<Song>)session.createCriteria(Song.class).add(Restrictions.not(Restrictions.in("id", ids))).list();
+            if(songs != null && !songs.isEmpty())
+                songs.forEach(session::delete);
+            session.getTransaction().commit();
+        }
+    }
+
     /**
      * @param target Data of song to find in database.
      * @return Song found with metadata or Optional.empty()
@@ -134,7 +149,7 @@ public class HibernateDatabase implements IDatabase{
      * If the song already exists it will be updated instead.
      * @param metadata New song information.
      */
-    public void addSong(ExtractedMetadata metadata) {
+    public Song addSong(ExtractedMetadata metadata) {
         try (Session session = getSession()) {
             session.beginTransaction();
             Optional<Album> albumObj = getOneAlbum(metadata.getAlbum());
@@ -151,16 +166,20 @@ public class HibernateDatabase implements IDatabase{
                 artistObj = Optional.of(artist);
             }
             Optional<Song> songObj = getOneSong(metadata);
-            if(!songObj.isPresent())
+            Song song;
-                session.save(new Song(metadata.getTrackNumber(), metadata.getDiscNumber(), metadata.getTitle(), artistObj.get(),
+            if(!songObj.isPresent()) {
-                        albumObj.get(), metadata.getGenre(), metadata.getSongFile()));
+                song = new Song(metadata.getTrackNumber(), metadata.getDiscNumber(), metadata.getTitle(), artistObj.get(),
+                        albumObj.get(), metadata.getGenre(), metadata.getSongFile());
+                session.save(song);
+            }
             else {
-                Song song = songObj.get();
+                song = songObj.get();
                 song.updateData(metadata.getTrackNumber(), metadata.getDiscNumber(), metadata.getTitle(), artistObj.get(),
                         albumObj.get(), metadata.getGenre(), metadata.getSongFile());
                 session.merge(song);
             }
             session.getTransaction().commit();
+            return song;
         }
     }
 

src/main/java/musicplayer/db/IDatabase.java

@@ -9,7 +9,8 @@ public interface IDatabase {
     Optional<Album> getOneAlbum(String name);
     Optional<Artist> getOneArtist(String name);
     Optional<Song> getOneSong(ExtractedMetadata metadata);
+    void batchDeleteNot(Long[] validIds);
     <T extends IDBType> Optional<List<T>> listAllT(Class<T> typeClass);
-    void addSong(ExtractedMetadata metadata);
+    Song addSong(ExtractedMetadata metadata);
     void addSong(Song song);
 }

src/main/java/musicplayer/library/ILibrary.java

@@ -4,6 +4,7 @@ import musicplayer.callbacks.LibraryCallbackInterface;
 import musicplayer.db.IDatabase;
 import musicplayer.model.ExtractedMetadata;
 import musicplayer.model.HasSongs;
+import musicplayer.model.Song;
 import org.jaudiotagger.audio.AudioFileIO;
 import org.jaudiotagger.audio.exceptions.CannotReadException;
 import org.jaudiotagger.audio.exceptions.InvalidAudioFrameException;
@@ -14,8 +15,10 @@ import org.jaudiotagger.tag.TagException;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Optional;
+import java.util.Set;
 
 public interface ILibrary {
     void showSongs();
@@ -34,13 +37,16 @@ public interface ILibrary {
         boolean callbacksEnabled = callbackInterface != null;
         rootDirectory.forEach(dir -> {
             try {
+                Set<Long> seenIds = new HashSet<>();
                 Files.walk(dir)
                         .filter(f -> f.toString().matches(musicFileExtensionRegex)).map(ILibrary::autoParse)
                         .forEach(x -> x.ifPresent(i -> {
-                            database.addSong(i);
+                            Song song = database.addSong(i);
+                            seenIds.add(song.getId());
                             if (callbacksEnabled)
                                 callbackInterface.currentlyUpdating(i.toString());
                         }));
+                database.batchDeleteNot(seenIds.toArray(new Long[seenIds.size()]));
             } catch (IOException e) {
                 if(callbacksEnabled)
                     callbackInterface.libraryUpdated(e.getMessage());

src/test/java/musicplayer/db/HibernateDatabaseTest.java

@@ -14,6 +14,7 @@ import java.io.File;
 import java.util.List;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
 
 public class HibernateDatabaseTest {
@@ -197,6 +198,22 @@ public class HibernateDatabaseTest {
         Artist newArtist = new Artist("Test 2");
         Song newSong = new Song("2", "2", "s2", newArtist, newAlbum, "g2", ""); // File same == Song same
         database.addSong(newSong);
-        assertEquals(database.listAllT(Song.class).get().size(), 1);
+        assertEquals(1, database.listAllT(Song.class).get().size());
+    }
+
+    @Test
+    public void testDeleteBatchNot() {
+        Song song1 = new Song("1", "1", "s1", new Artist("a"), new Album("a"), "", "1");
+        Song song2 = new Song("2", "1","s2", new Artist("b"), new Album("a"), "", "2");
+        Song song3 = new Song("1", "1","t1", new Artist("c"), new Album("b"), "", "3");
+        database.addSong(song1);
+        database.addSong(song2);
+        database.addSong(song3);
+        database.batchDeleteNot(new Long[]{song1.getId(), song2.getId()});
+        List<Song> db = database.listAllT(Song.class).get();
+        assertEquals(2, db.size());
+        assertTrue(db.contains(song1));
+        assertTrue(db.contains(song2));
+        assertFalse(db.contains(song3));
     }
 }