java功能移植问题咨询。

使用java怎么编写一个包含水印的记事本程序？目前记事本功能已经实现，水印添加部分移植到记事本程序中之后，运行没有显示，各位指导一下。

以下是添加水印的部分代码

@Override
    // public class MyPanel extends JPanel {
    public void paint(Graphics g) {
        super.paint(g);

        // Get the size of the text area
        int textAreaWidth = jf.getWidth();
        int textAreaHeight = jf.getHeight();
        // int textAreaWidth = 800;
        // int textAreaHeight = 800;

        // Create a new BufferedImage to hold the watermark and text
        BufferedImage bufferedImage = new BufferedImage(textAreaWidth, textAreaHeight,
                BufferedImage.TYPE_INT_ARGB);

        // Draw the text onto the buffered image
        Graphics2D g2d = bufferedImage.createGraphics();
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g2d.setFont(watermarkFont);
        g2d.setColor(watermarkColor);
        g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f));
        // 将文字倾斜30度
        g2d.rotate(Math.toRadians(-30), jf.getWidth() / 2, jf.getHeight() / 2);
        // g2d.rotate(Math.toRadians(-30), 800 / 2, 800 / 2);
        g2d.drawString(watermarkText, 20, textAreaHeight - 210);

        // Draw the text area onto the buffered image
        jf.print(g2d);

        // Draw the buffered image onto the main window
        g.drawImage(bufferedImage, 100, 100, null);

        // 释放资源
        // g2d.dispose();
    }

paint里面下断点调试下，有没有运行进来。