JScrollpane, Graphics, Image, jpg

Question

I'm try to load a jpg file in a jscrollpane and would like to draw on this jpg file any circels, lines or rectangle in a method . But it doesn't run, can anybody help me? thanks
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class JScroll extends JFrame {
   static Graphics g = null;
   static Image image;
   public static void main(String args[]) {
      JScroll wnd = new JScroll();
   public JScroll() {
      super("JScrollPane");
      setBackground(Color.lightGray);
      setSize(400, 400);
      //WindowListener
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent e) {
            System.exit(0);
      image = getToolkit().getImage("neutral.jpg");
      g.drawImage(image, 20, 20, this);
      JScrollPane jScrollPane = new JScrollPane(g, VERTICAL_SCROLLBAR_ALWAYS, HORIZONTAL_SCROLLBAR_ALWAYS);
      jScrollPane.setSize(300, 300);
      JPanel p1 = new JPanel();
      p1.setLayout(new BorderLayout());
      p1.add(jScrollPane, BorderLayout.CENTER);
      getContentPane().add(p1);
      paint(40,40);
      setVisible(true);
   public void paint( int y, int z) {
      g.drawImage(image, y, z, this);
}

Answer 1

Thank you for the answers! I have moved my drawMore() Methode, now I can use that Graphics object, but it doesn't draw the black Rectangels, only the red one. Why?
The paintComponent() redraw all and load the jpg again on every repaint() call. How can I only update the Graphic object?
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.geom.Rectangle2D;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
public class JScrollRx extends JFrame {
     AnImagePanel p1;
     public static void main(String args[]) {
          JScrollRx wnd = new JScrollRx();
     public JScrollRx() {
          super("JScrollPane");
          setBackground(Color.lightGray);
          setSize(400, 400);
          setLocation(200, 200);
          //WindowListener
          addWindowListener(new WindowAdapter() {
               public void windowClosing(WindowEvent e) {
                    System.exit(0);
          JPanel p0 = new JPanel();
          p0.setLayout(new BorderLayout());
          p1 = new AnImagePanel(loadImage());
          p0.add(new JScrollPane(p1), BorderLayout.CENTER);
          p0.add(new JLabel("Title"), BorderLayout.NORTH);
          getContentPane().add(p0);
          setVisible(true);
          p1.drawMore(200,200);
     private Image loadImage() {
          Image image = getToolkit().getImage("neutral.jpg");
          // make sure image is loaded before we try to use it
          MediaTracker tracker = new MediaTracker(this);
          tracker.addImage(image, 0);
          try {
               tracker.waitForID(0);
          } catch (InterruptedException ie) {
               System.err.println("interrupt: " + ie.getMessage());
          return image;
     public class AnImagePanel extends JPanel {
          private Graphics g;
          private Graphics2D g2d;
          Image image = null;
          public AnImagePanel(Image im) {
               image = im;
          public void paintComponent(Graphics g) {
               super.paintComponent(g);
               g2d = (Graphics2D) g;
               int w = getWidth();
               int h = getHeight();
               int imageWidth = image.getWidth(this);
               int imageHeight = image.getHeight(this);
               int x = (w - imageWidth) / 2;
               int y = (h - imageHeight) / 2;
               g2d.drawImage(image, x, y, this);
               g2d.setPaint(Color.red);
               g2d.draw(new Rectangle2D.Double(w / 2 - 20, h / 2 - 20, 40, 40));
          public Dimension getPreferredSize() {
               return new Dimension(image.getWidth(this), image.getHeight(this));
          public void drawMore(int x, int y){
               g2d.setPaint(Color.black);
               g2d.draw(new Rectangle2D.Double(x, y, 40, 40));
               repaint();
}