import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JWindow;
public class Main {
public static void main(String[] arg) throws Exception {
Dimension screenDim = Toolkit.getDefaultToolkit().getScreenSize();
Robot robot = new Robot();
BufferedImage image = robot.createScreenCapture(new Rectangle(0, 0, (int) screenDim.getWidth(),
(int) screenDim.getHeight()));
JWindow window = new JWindow(new JFrame());
window.getContentPane().setLayout(new BorderLayout());
window.getContentPane().add(BorderLayout.CENTER, new JLabel(new ImageIcon(image)));
window.pack();
window.setVisible(true);
}
}