Dalam program ini terdapat 4 Class, yaitu:   1. ImageViewer   2. ImagePanel   3. OFImage   4. Image File Manager   Berikut adalah tampilan hubungan tiap class di BlueJ.     Berikut adalah source code tiap classnya.   1. ImageViewer   /**     * Write a description of class ImageViewer here.     *     * @author (your name)     * @version (a version number or a date)     */    import java.awt.*;    import java.awt.event.*;    import java.awt.image.*;    import javax.swing.*;    import java.io.File;    public class ImageViewer    {      private static final String VERSION = "Version 1.0";      private static JFileChooser fileChooser = new JFileChooser      (System.getProperty("user.dir"));      private JFrame frame;      private ImagePanel imagePanel;      private JLabel filenameLabel;      private JLabel statusLabel;      private OFImage currentImage;      public ImageViewer()      {        currentImage = null;        makeFrame();      }      private void openFile()   ...