Scroll em um JDialog

Olá pessoal!
Eu peguei esse código da internet. Soh que eu não preciso que quando a JDialog seja criado, ele seja criado com um Scroll. Mas não tô sabendo como fazer isso. Vcs podem tentar me ajudar?

public class NewJDialog extends javax.swing.JDialog {

    public NewJDialog(java.awt.Frame parent, boolean modal) {
        super(parent, modal);
        initComponents();
        java.awt.Image i;
        int width = 200;
        int height = 200;
        int[] pixels = new int[width * height];
        int c;
        double radianConversion = Math.PI / 180.0;
        for (int index = 0, y = 0; y < height; y++) {
            c = ((0xff)
                    & (byte) (Math.abs(Math.sin((y + height) * radianConversion)) * 255));
            for (int x = 0; x < width; x++) {
                pixels[index++] = ((0xff << 24) | (c << 16) | (c << 8) | c);
            }
        }
        i = createImage (new MemoryImageSource (width, height, pixels, 0, width));
        setFont(new Font("TimesRoman", Font.BOLD | Font.ITALIC, 32));
    }
    @Override
    public void paint(Graphics g) {
        g.drawString("JavaWorld", 30, 80);
 }
}

    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 400, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 300, Short.MAX_VALUE)
        );

        pack();
    }// </editor-fold>
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                NewJDialog dialog = new NewJDialog(new javax.swing.JFrame(), true);
                dialog.setSize(250,200);
                
                dialog.addWindowListener(new java.awt.event.WindowAdapter() {

                    @Override
                    public void windowClosing(java.awt.event.WindowEvent e) {
                        System.exit(0);


                    }
                });
                dialog.setVisible(true);


            }
        });

    }
   
}