JWindow is Swing’s version of Window and is descended directly from that class. Like Window, it uses BorderLayout by default. Almost all Swing components are lightweight except JApplet, JFrame, JDialog, and JWindow.

Constructors:

Window(Frame owner) - Constructs a new invisible window with the specified Frame as its owner.
Window(Window owner) - Constructs a new invisible window with the specified Window as its owner.
Window(Window owner, GraphicsConfiguration gc) - Constructs a new invisible window with the specified window as its owner and a GraphicsConfiguration of a screen device.

public class JWindowDemo extends JWindow {
            private int X = 0;
            private int Y = 0;
            public JWindowDemo() {
                        setBounds(60, 60, 100, 100);
                        addWindowListener(new WindowAdapter() {
                                    public void windowClosing(WindowEvent e) {
                                                System.exit(0); // An Exit Listener
                                    }   });
                        addMouseListener(new MouseAdapter() {
                                    public void mousePressed(MouseEvent e) {
                                                X = e.getX();
                                                Y = e.getY();
                                                System.out.println("The (X,Y) coordinate of window is (" + X + "," + Y + ")");
                                    } });
                        addMouseMotionListener(new MouseMotionAdapter() {
                                    public void mouseDragged(MouseEvent e) {
                                         setLocation(getLocation().x + (e.getX() - X),
                                                            getLocation().y + (e.getY() - Y));
                                    } });
                        setVisible(true);
            }
            public static void main(String[] args) {
                        new JWindowDemo();
            }
}