Drag and Drop images into Jpanel and put them in app directory

Question

I found this tutorial: Drag and dropping files to a Java desktop application

It correctly shows the panel and enables the drop-and-dragging but it sends out error

Can only iterate over an array or an instance of java.lang.Iterable

referring to the passage:

  for (File file : files) {
       // Print out the file path
        System.out.println("File path is '" + file.getPath() + "'.");
    }

I really don't know how to solve the problem... Could you plese help me?

Update:

If I try doing this:

List File[] files = (File[]) transferable.getTransferData(flavor);

it keeps giving me an error...

So I tried doing this:

File[] files = (File[]) transferable.getTransferData(flavor);

and the code is no longer underlined but it keeps not working.

I also found another tutorial:

how to drag and drop files from a directory in java

It doesn't work of course -.-'

I think the closest thing I have to the solution is this complete example:

import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.UnsupportedFlavorException;
import java.io.File;
import java.io.IOException;
import java.util.List;

import javax.swing.*;

@SuppressWarnings("serial")
public class FileDragDemo extends JPanel {
private JList list = new JList();

public FileDragDemo() {
  list.setDragEnabled(true);
  list.setTransferHandler(new FileListTransferHandler(list));

  add(new JScrollPane(list));
}

 private static void createAndShowGui() {
  FileDragDemo mainPanel = new FileDragDemo();

  JFrame frame = new JFrame("FileDragDemo");
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.getContentPane().add(mainPanel);
  frame.pack();
  frame.setLocationByPlatform(true);
  frame.setVisible(true);
}

    public static void main(String[] args) {
     SwingUtilities.invokeLater(new Runnable() {
        public void run() {
          createAndShowGui();
        }
     });
  }
}

@SuppressWarnings("serial")
class FileListTransferHandler extends TransferHandler {
private JList list;

public FileListTransferHandler(JList list) {
  this.list = list;
 }

public int getSourceActions(JComponent c) {
  return COPY_OR_MOVE;
}

public boolean canImport(TransferSupport ts) {
  return ts.isDataFlavorSupported(DataFlavor.javaFileListFlavor);
}

public boolean importData(TransferSupport ts) {
   try {
     @SuppressWarnings("rawtypes")
     List data = (List) ts.getTransferable().getTransferData(
           DataFlavor.javaFileListFlavor);
     if (data.size() < 1) {
        return false;
     }

     DefaultListModel listModel = new DefaultListModel();
     for (Object item : data) {
        File file = (File) item;
        listModel.addElement(file);
     }

     list.setModel(listModel);
     return true;

  } catch (UnsupportedFlavorException e) {
     return false;
  } catch (IOException e) {
     return false;
  }
}
}

The only problem is that I want the panel to show all the images I upload, instead it only displays the last entry

For better help sooner, post an [MCVE](http://stackoverflow.com/help/mcve) (Minimal Complete Verifiable Example) or [SSCCE](http://www.sscce.org/) (Short, Self Contained, Correct Example). Don't expect people to follow links to code, it should be in the question. — Andrew Thompson, Jan 13 '15 at 09:40
You are [required](http://stackexchange.com/legal) to cite the [original source code](http://stackoverflow.com/a/13597312/230513). — trashgod, Jan 13 '15 at 11:13

score 0 · Answer 1 · answered Jan 13 '15 at 09:41

Nice article... Just please change List files to List< File > files :) Again great article!

^First comment on that link.

also when coding be weary of some tutorials from 2011 etc. as they can often teach you the wrong way to do something. Not that i know enough about this topic to suggest anything better.

Drag and Drop images into Jpanel and put them in app directory

1 Answers1