public class ScreenShot
{
    public static void main(String[] args)
    {
        try
        {
            // Get the screen size
            Dimension screenSize =
Toolkit.getDefaultToolkit().getScreenSize();
            Rectangle rectangle = new Rectangle(0, 0, screenSize.width,
                    screenSize.height);
            Robot robot = new Robot();
            BufferedImage image = robot.createScreenCapture(rectangle);
            File file;

            // Save the screenshot as a png
            file = new File("screen.png");
            ImageIO.write(image, "png", file);

        } catch (Exception e)
        {
            System.out.println(e.getMessage());
        }
    }
}

   The "Graphics" object is like a pen, and a "Image" object is like a
sheet of paper. That is, the drawing is stored in the "Image" object, and
not in the "Graphics" object, just like the drawing is stored on the paper,
and not in the pen.

   Thus it does not make sense to take drawing data out of a Graphic object
to put into an Image object, since the Graphic object doesn't contain any
drawing data.

   You need to get the surface onto which the Graphic draws upon, and get
the drawing data from that.

   - Oliver

Since Graphics objects as such don't hold any image or drawing data,
except from some state, this is not going to happen. A Graphics object
just provides a drawing context to "something". You need to get that
"something" and check if/how you can get some image data out of it.

Graphics doesn't hold image data.

/Thomas