Cannot plot Ovals on the Map on mouse Clicks

Question

Hi all...
I am able to load the map of the South Pacific but I am not able to plot ovals on it . The following is my cod and the exception is also given below the code when i click the mouse. code is based on java 1.5 sdk
Please could anyone correct me with the correct code so that i am able to load the map and click the mouse to draw the points.
Cheers
Jitendra
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;
public class Map extends JPanel {
   protected ImageIcon icon;
   protected Point fp;//start = new Point(0, 0);
   protected Point tp;//finish = new Point(0, 0);
   Graphics  grf;
   public static void main (String[] args) {
      String file = "../pic/Pic2.JPG";
      if (args.length == 0) {
         System.out.println("You must specify the name of an image file");
         return;
         //args[0] = file;
         Map editor = new Map(args[0]);
         JFrame f = new JFrame(args[0]);
         f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
         f.setContentPane(editor);
         f.setSize(800, 700);
         f.setVisible(true);
         //f.getContentPane().add(editor);
   public Map(String name) {
      super();
      setLayout(new GridLayout(1,1,0,0));
      icon = new ImageIcon(name);
      JLabel label = new JLabel(icon);
      label.setHorizontalAlignment(SwingConstants.LEFT);
      label.setVerticalAlignment(SwingConstants.TOP);
      label.addMouseListener(new MouseAdapter() {
         public void mousePressed(MouseEvent event) {
            handleMouseDown(event);
         public void mouseReleased(MouseEvent e){
                /*tp = e.getPoint();
                grf.setColor(Color.blue);
                System.out.println("Tp " + tp);
                //grf.drawLine(fp.x,fp.y,tp.x,tp.y);
                //grf.fillOval(fp.x,fp.y,15,15);
                grf.fillOval(tp.x,tp.y,15,15);
                repaint();*/
      label.addMouseMotionListener(new MouseMotionAdapter() {
                public void mouseDragged(MouseEvent event) {
                        handleMouseDrag(event);
      JScrollPane jsp = new JScrollPane(label);
      add(jsp);
   protected void handleMouseDown(MouseEvent ev) {
      //if((ev.getModifiers() & InputEvent.BUTTON1_MASK) != 0) {
         //start = event.getPoint();
         //finish = event.getPoint();
         tp = ev.getPoint();
         //System.out.println("fp " + fp);
         grf.setColor(Color.blue);
         System.out.println("Tp " + tp);
                //grf.drawLine(fp.x,fp.y,tp.x,tp.y);
                //grf.fillOval(fp.x,fp.y,15,15);
                grf.fillOval(tp.x,tp.y,15,15);
         //repaint();
         //System.out.println("Finish " + finish);
   protected void handleMouseDrag(MouseEvent ev) {
      //finish = event.getPoint();
      //tp = ev.getPoint();
      //System.out.println("DragFinish " + finish);
      //repaint();
   public void paintComponent(Graphics g){
   /*if (image == null){
                image = createImage(getWidth(),getHeight());
                grf   = image.getGraphics();
                grf.setColor(getBackground());
                grf.fillRect(0,0,getWidth(),getHeight());
                //g.drawImage(image,0,0,null);
                //g.setColor(dfltcolor);
                //grf   = icon.getGraphics();
                this.grf = g;
                g.drawLine(fp.x,fp.y,tp.x,tp.y);
                g.fillOval(fp.x,fp.y,15,15);
                g.fillOval(tp.x,tp.y,15,15);
}/* Exception
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at Map$1.mouseReleased(Map.java:50)
at java.awt.Component.processMouseEvent(Component.java:5488)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3126)
at java.awt.Component.processEvent(Component.java:5253)
at java.awt.Container.processEvent(Container.java:1966)
at java.awt.Component.dispatchEventImpl(Component.java:3955)
at java.awt.Container.dispatchEventImpl(Container.java:2024)
at java.awt.Component.dispatchEvent(Component.java:3803)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4212)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3892)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3822)
at java.awt.Container.dispatchEventImpl(Container.java:2010)
at java.awt.Window.dispatchEventImpl(Window.java:1774)
at java.awt.Component.dispatchEvent(Component.java:3803)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:242)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:163)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
*/

Answer 1

Roughly put, don't access Graphics object outside the
paintComponent() method.
And, don't use Graphics object other than that is
passed as the argument of the
paintComponent() method for painting on the
component.
If you want to draw on an Image object before
painting it on the component, use BufferedImage
and the Graphics object gotten from its method. After
that, use g.drawImage() method in the
paintComponent() method.
Your grf variable is complete nonsense.
Delete it.
Most importantly: learn Java GUI programming basics
before anything else.
See:
http://java.sun.com/docs/books/tutorial/uiswing/index.
htmlThanks very much but how I gonna use to load the image...since I haven't done any java before this is my first time as it is required in my project........pls some one help me.........