public class Test extends JFrame {

    private JPanel contentPane;

    public static void main(String[] args) {

        Test frame = new Test();

    }

    public Test() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        contentPane.setLayout(new BorderLayout(0, 0));
        setContentPane(contentPane);
        Image img = new ImageIcon("images/1.jpg").getImage();
        BufferedImage buImage = new BufferedImage(450,
                300, BufferedImage.TYPE_INT_ARGB_PRE);
        Graphics graphics = buImage.getGraphics();
        graphics.drawImage(img, 0, 0, 450, 300, null);
        this.setVisible(true);
    }

}

绘图的话应该要用到Graphics类！