Image.getWidth(ImageObserver obs) returns -1

Question

hello everyone i have used following code to load an image
URL location=Sprite.class.getClassLoader().getResource(path);
    img=Toolkit.getDefaultToolkit().getImage(location);and this code to draw an image:
g2d.drawImage(img, x, y, this);now i need to know the width and height of image for detecting collision.
getWidth() and getHeight() returns -1.
System.out.println(img.getWidth(this));my images are getting displayed in the frame.but when i try to access width and height of an image then it returns -1 which means width and height of image is not known yet.
help !!
thanks.

Answer 1

sorry.
This problem is in my game code.Since the code is very long so i am giving a small code reflecting my problem
import java.awt.Image;
import java.awt.Toolkit;
import java.net.URL;
import javax.swing.*;
import java.awt.Graphics;
public class Sprite extends JPanel
private JFrame frame;
private Image img;
public Sprite()
frame=new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(500,400);
frame.getContentPane().add(this);
frame.setVisible(true);
URL location=Sprite.class.getClassLoader().getResource("small.jpg");
img=Toolkit.getDefaultToolkit().getImage(location);
this.repaint();
System.out.println(img.getWidth(null));
public void paintComponent(Graphics g)
g.drawImage(img,150,150,this);
public static void main(String[] args)
new Sprite();
}So i want the width and height of an image.But when i try to get it, it just returns -1 which means width and height is not known yet, according to java doc.
if i use img=new ImageIcon("small.jpg").getImage() to load an image and if i access the width and height of an image using img.getWidth(ImageObserver obs) then i get correct value of width and height.
i want to use above code that i provided to load an image.So pls help me out.Why it is returning -1 ?.
Edited by: JGarage on Dec 6, 2008 7:59 AM
Edited by: JGarage on Dec 6, 2008 8:00 AM