Refactored album art retrieval to prevent repeat loading of the same image into memory.

src/main/java/musicplayer/AlbumArtExtractor.java

@@ -0,0 +1,84 @@
+package musicplayer;
+
+import org.jaudiotagger.audio.AudioFileIO;
+import org.jaudiotagger.audio.exceptions.CannotReadException;
+import org.jaudiotagger.audio.exceptions.InvalidAudioFrameException;
+import org.jaudiotagger.audio.exceptions.ReadOnlyFileException;
+import org.jaudiotagger.tag.Tag;
+import org.jaudiotagger.tag.TagException;
+
+import javax.imageio.ImageIO;
+import java.awt.*;
+import java.awt.image.BufferedImage;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Optional;
+
+public final class AlbumArtExtractor {
+
+    private static final String albumArtRegex = ".*(Cover|Folder|cover|folder)\\.(jpg|png)";
+
+    /**
+     * Get the album art for a song file.
+     * @param songFile File from which to get album art data
+     *                 (Data is either extracted from file metadata or an image in the same folder).
+     * @return Album art as a byte array.
+     */
+    public static byte[] getImageData(File songFile){
+        Tag audioTags = null;
+        try {
+            audioTags = AudioFileIO.read(songFile).getTag();
+        } catch (CannotReadException | IOException | ReadOnlyFileException | TagException | InvalidAudioFrameException e) {
+            return null;
+        }
+        byte[] tmpArt = null;
+        try {
+            tmpArt = audioTags.getFirstArtwork().getBinaryData();
+            BufferedImage image = ImageIO.read(new ByteArrayInputStream(tmpArt));
+            tmpArt = convertImageToBytes(image);
+        } catch (IOException | NullPointerException e) {
+            try {
+                Path dir = songFile.toPath().getParent();
+                Optional<Path> imageFile = Files.walk(dir).filter(x -> x.toString().matches(albumArtRegex)).findFirst();
+                if (imageFile.isPresent()) {
+                    Image actualImage = ImageIO.read(imageFile.get().toFile());
+                    tmpArt = convertImageToBytes(actualImage);
+                }
+            } catch (NullPointerException | IOException ignored) {}
+        }
+        return tmpArt;
+    }
+
+    /**
+     * Convert an Image into its' byte array representation.
+     * @param image Image to convert.
+     * @return image as byte[].
+     */
+    private static byte[] convertImageToBytes(Image image){
+        int imageScaleToSize = 50;
+        try (ByteArrayOutputStream baos = new ByteArrayOutputStream()){
+            ImageIO.write(convertToBufferedImage(image.getScaledInstance(imageScaleToSize, imageScaleToSize, Image.SCALE_SMOOTH)), "jpg", baos);
+            baos.flush();
+            return baos.toByteArray();
+        } catch (IOException e) { return null; }
+    }
+
+    /**
+     * Convert an Image to a BufferedImage.
+     * @param image Source image.
+     * @return image as BufferedImage.
+     */
+    private static BufferedImage convertToBufferedImage(Image image) {
+        BufferedImage newImage = new BufferedImage(
+                image.getWidth(null), image.getHeight(null),
+                BufferedImage.TYPE_INT_ARGB);
+        Graphics2D g = newImage.createGraphics();
+        g.drawImage(image, 0, 0, null);
+        g.dispose();
+        return newImage;
+    }
+}

src/main/java/musicplayer/db/Gateway.java

@@ -1,10 +1,12 @@
 package musicplayer.db;
 
+import musicplayer.AlbumArtExtractor;
 import musicplayer.model.*;
 import org.hibernate.Criteria;
 import org.hibernate.Session;
 import org.hibernate.criterion.Restrictions;
 
+import java.io.File;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -94,7 +96,7 @@ public class Gateway {
             session.beginTransaction();
             Optional<Album> albumObj = getOneAlbum(metadata.album);
             if (!albumObj.isPresent()) {
-                Album album = new Album(metadata.album, metadata.artwork);
+                Album album = new Album(metadata.album, AlbumArtExtractor.getImageData(new File(metadata.songFile)));
                 albumObj = Optional.of(album);
             }
             Optional<Artist> artistObj = getOneArtist(metadata.artist);

src/main/java/musicplayer/model/ExtractedMetadata.java

@@ -24,11 +24,8 @@ public class ExtractedMetadata {
     public final String genre;
     public final String songFile;
     public final String trackNumber;
-    public final byte[] artwork;
     public final String discNumber;
 
-    private static final String albumArtRegex = ".*(Cover|Folder|cover|folder)\\.(jpg|png)";
-
     /**
      * @param audioTags jaudiotagger tag data.
      * @param songFile  Location of the song file on the filesystem.
@@ -41,51 +38,6 @@ public class ExtractedMetadata {
         this.genre = audioTags.getFirst(FieldKey.GENRE);
         this.discNumber = audioTags.getFirst(FieldKey.DISC_NO);
         this.songFile = songFile.getAbsolutePath();
-        byte[] tmpArt = null;
-        try {
-            tmpArt = audioTags.getFirstArtwork().getBinaryData();
-            BufferedImage image = ImageIO.read(new ByteArrayInputStream(tmpArt));
-            tmpArt = convertImageToBytes(image);
-        } catch (IOException | NullPointerException e) {
-            try {
-                Path dir = songFile.toPath().getParent();
-                Optional<Path> imageFile = Files.walk(dir).filter(x -> x.toString().matches(albumArtRegex)).findFirst();
-                if (imageFile.isPresent()) {
-                    Image actualImage = ImageIO.read(imageFile.get().toFile());
-                    tmpArt = convertImageToBytes(actualImage);
-                }
-            } catch (NullPointerException | IOException ignored) {}
-        }
-        artwork = tmpArt;
-    }
-
-    /**
-     * Convert an Image into its' byte array representation.
-     * @param image Image to convert.
-     * @return image as byte[].
-     */
-    private static byte[] convertImageToBytes(Image image){
-        int imageScaleToSize = 50;
-        try (ByteArrayOutputStream baos = new ByteArrayOutputStream()){
-            ImageIO.write(convertToBufferedImage(image.getScaledInstance(imageScaleToSize, imageScaleToSize, Image.SCALE_SMOOTH)), "jpg", baos);
-            baos.flush();
-            return baos.toByteArray();
-        } catch (IOException e) { return null; }
-    }
-
-    /**
-     * Convert an Image to a BufferedImage.
-     * @param image Source image.
-     * @return image as BufferedImage.
-     */
-    private static BufferedImage convertToBufferedImage(Image image) {
-        BufferedImage newImage = new BufferedImage(
-                image.getWidth(null), image.getHeight(null),
-                BufferedImage.TYPE_INT_ARGB);
-        Graphics2D g = newImage.createGraphics();
-        g.drawImage(image, 0, 0, null);
-        g.dispose();
-        return newImage;
     }
 
     @Override