Java SE (Java Platform, Standard Edition)

I'm trying to copy an image with a transparent background to the clipboard, but when I paste it in Photoshop (for an example) the background comes out as black. This is my code:

import java.awt.*;
import java.awt.datatransfer.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;

public class CopyExample 
        extends JFrame 
        implements ActionListener {

    public static void main(String[] args) {
        new CopyExample();
    }    
    
    public CopyExample() {
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setSize(200, 200);
        JButton button = new JButton("Copy");
        button.addActionListener(this);
        add(button);
        setVisible(true);
    }
    
    public void actionPerformed(ActionEvent e) {
        final BufferedImage image = new BufferedImage(
                200, 200, BufferedImage.TYPE_INT_ARGB);
        Graphics2D g2 = image.createGraphics();
        
        g2.setComposite(AlphaComposite.Clear);
        g2.fillRect(0, 0, 200, 200);
        
        g2.setComposite(AlphaComposite.SrcOver);
        g2.setColor(Color.GREEN);
        g2.fillRect(50, 50, 100, 100);
        g2.dispose();

        Transferable transf = new ImageTransferable(image);
        
        Toolkit.getDefaultToolkit()
                .getSystemClipboard()
                .setContents(transf, null);    
        
//        try {
//            ImageIO.write(image, "png", new File("out.png"));
//        } catch(IOException ex) { ex.printStackTrace(); }
    }
}

class ImageTransferable implements Transferable {
    private Image image;
    
    public ImageTransferable(Image image) {
        this.image = image;
    }
    
    public DataFlavor[] getTransferDataFlavors() {
        return new DataFlavor[] { 
            DataFlavor.imageFlavor 
        };                
    }
    public boolean isDataFlavorSupported(DataFlavor flavor) {
        return flavor.match(DataFlavor.imageFlavor);
    }
    public Object getTransferData(DataFlavor flavor) 
            throws UnsupportedFlavorException, IOException {                
        return image;
    }    
}

I'm creating a BufferedImage and clears the background first, just to be sure. And then I copy it to the clipboard. I also tried to save it to a PNG file and that works fine. Any ideas?