class DroppableFrame extends JFrame implements DropTargetListener, DragSourceListener,
        DragGestureListener
 {

    private DragSource dragSource = DragSource.getDefaultDragSource();

    /**
     * Creates a droppable rame.
     */
    public DroppableFrame() {
        new DropTarget(this, this);
        dragSource.createDefaultDragGestureRecognizer(this, DnDConstants.ACTION_COPY_OR_MOVE, this);
    }

    @Override
    public void dragDropEnd(DragSourceDropEvent DragSourceDropEvent) {
    }

    @Override
    public void dragEnter(DragSourceDragEvent DragSourceDragEvent) {
    }

    @Override
    public void dragExit(DragSourceEvent DragSourceEvent) {
    }

    @Override
    public void dragOver(DragSourceDragEvent DragSourceDragEvent) {
    }

    @Override
    public void dropActionChanged(DragSourceDragEvent DragSourceDragEvent) {
    }

    @Override
    public void dragEnter(DropTargetDragEvent dropTargetDragEvent) {
        dropTargetDragEvent.acceptDrag(DnDConstants.ACTION_COPY_OR_MOVE);
    }

    @Override
    public void dragExit(DropTargetEvent dropTargetEvent) {
    }

    @Override
    public void dragOver(DropTargetDragEvent dropTargetDragEvent) {
    }

    @Override
    public void dropActionChanged(DropTargetDragEvent dropTargetDragEvent) {
    }

    @Override
    public void drop(DropTargetDropEvent dropTargetDropEvent) {<FILL_FUNCTION_BODY>}

    @Override
    public void dragGestureRecognized(DragGestureEvent dragGestureEvent) {

    }

    /**
     * Notified when a file has been dropped onto the frame.
     *
     * @param file the file that has been dropped.
     */
    public void fileDropped(File file){

    }

    /**
     * Notified when a directory has been dropped onto the frame.
     *
     * @param file the directory that has been dropped.
     */
    public void directoryDropped(File file){

    }
}

        try {
            Transferable transferable = dropTargetDropEvent.getTransferable();
            if (transferable.isDataFlavorSupported(DataFlavor.javaFileListFlavor)) {
                dropTargetDropEvent.acceptDrop(DnDConstants.ACTION_COPY_OR_MOVE);
                List fileList = (List) transferable.getTransferData(DataFlavor.javaFileListFlavor);
                Iterator iterator = fileList.iterator();
                while (iterator.hasNext()) {
                    File file = (File) iterator.next();
                    if (file.isFile()) {
                        fileDropped(file);
                    }

                    if (file.isDirectory()) {
                        directoryDropped(file);
                    }
                }
                dropTargetDropEvent.getDropTargetContext().dropComplete(true);
            }
            else {
                dropTargetDropEvent.rejectDrop();
            }
        }
        catch (IOException | UnsupportedFlavorException io) {
            io.printStackTrace();
            dropTargetDropEvent.rejectDrop();
        }
    
<methods>public void <init>() throws java.awt.HeadlessException,public void <init>(java.awt.GraphicsConfiguration) ,public void <init>(java.lang.String) throws java.awt.HeadlessException,public void <init>(java.lang.String, java.awt.GraphicsConfiguration) ,public javax.accessibility.AccessibleContext getAccessibleContext() ,public java.awt.Container getContentPane() ,public int getDefaultCloseOperation() ,public java.awt.Component getGlassPane() ,public java.awt.Graphics getGraphics() ,public javax.swing.JMenuBar getJMenuBar() ,public javax.swing.JLayeredPane getLayeredPane() ,public javax.swing.JRootPane getRootPane() ,public javax.swing.TransferHandler getTransferHandler() ,public static boolean isDefaultLookAndFeelDecorated() ,public void remove(java.awt.Component) ,public void repaint(long, int, int, int, int) ,public void setContentPane(java.awt.Container) ,public void setDefaultCloseOperation(int) ,public static void setDefaultLookAndFeelDecorated(boolean) ,public void setGlassPane(java.awt.Component) ,public void setIconImage(java.awt.Image) ,public void setJMenuBar(javax.swing.JMenuBar) ,public void setLayeredPane(javax.swing.JLayeredPane) ,public void setLayout(java.awt.LayoutManager) ,public void setTransferHandler(javax.swing.TransferHandler) ,public void update(java.awt.Graphics) <variables>protected javax.accessibility.AccessibleContext accessibleContext,private int defaultCloseOperation,private static final java.lang.Object defaultLookAndFeelDecoratedKey,protected javax.swing.JRootPane rootPane,protected boolean rootPaneCheckingEnabled,private javax.swing.TransferHandler transferHandler