如何在包含全屏图像的JPanel上叠加JTextArea

Question

    public static JTextArea area = new JTextArea()
{
    public void createObject()
    {
        setLineWrap(true);
        setSize(850, 1100);
        setOpaque(true);
        setBackground(Color.WHITE);
        setBounds(0, 0, 850, 1100);
        setBorder(BorderFactory.createLineBorder(Color.lightGray, 1));
        setBorder(new EmptyBorder(new Insets(100, 100, 100, 100)));
        setFont(new Font("TimesRoman", Font.PLAIN, 11)); 
    }
};

public static JPanel panelImg = new JPanel()
{
    public void paintComponent(Graphics g)
    {
        try{
            add(area);
            Image img = new ImageIcon(ImageIO.read(new File("C:\\Program Files (x86)\\Oasis Script Writer\\Textures\\Backgrounds\\Background.jpg"))).getImage();
            Dimension size = new Dimension(img.getWidth(null), img.getHeight(null));
            setPreferredSize(size);
            setMinimumSize(size);
            setMaximumSize(size);
            setSize(size);
            setLayout(null);
            g.drawImage(img, 0, 0, null);
        } catch (Exception backgroundError) {
            System.out.println("ERROR: " + backgroundError);
        }
    }
};

我的目标是将jtextarea覆盖在包含全屏图像的jpanel上，这样我就可以将jtextarea放在jscrollpane中，而不会影响jpanel及其包含的图像。提前谢谢。

之后我将jpanel添加到jframe，意图将jtextarea添加到jpanel并重叠图像背景。

JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.getContentPane().add(panelImg);

见图：https://drive.google.com/file/d/0B9e6NVTCbgdwTFNkRlFDUkNYVXM/view?usp=sharing