a Problem with java 2D

Hi everybody,
i'm new to Java 2D and I have a Problem drawing a geometric primitive
on a JPanel.
I used getGraphics() to get the Graphics-Object of my JPanel, casted
it to Graphics2D, then drew a line on it und used myJPanel.repaint()
to update the JPanel.

But somehow I can't see the line I'v drawn and i can't figure it out
why .

the following is my code (without import statements):
.......................................................................................................
public class NewJFrame extends JFrame {

    private JPanel pane = null;

    /** Creates new instance */
    public NewJFrame() {
        initComponents();

        // draw a line on JPanel
        Graphics2D canvas = (Graphics2D)pane.getGraphics();
        canvas.setPaint(Color.BLUE);
        canvas.draw(new Line2D.Float(1,1,111,111));
        pane.repaint();
    }

    private void initComponents() {
     Dimension min = new Dimension(300,300);
        setMinimumSize(min);
 
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        pane = new JPanel();
        setContentPane(pane);
        pane.setBackground(new Color(255, 204, 255));
        pane.setForeground(new Color(51, 51, 255));
        pack();
    }

    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }
}
.......................................................................................................

Any help would be greatly appreicated, because I am deeply confused
and frustrated.