In that case, put it and your application in a jar file. This makes locating
the graphic must more likely. You are not likely to be able to use relative
addressing if the required elements are not packaged in some way. It's not
impossible, it's just a lot of effort when creating a jar file is simpler
and has other advantages as well.

Try printing:
String dir = System.getProperty("user.dir");

For example if you are using netbeans, netbeans will start Java from
it's home directory. If this is the case then you have to edit the class
path in the IDE or move your image to the location identified. Does the
program see the image when you run it from the command line & you have
the image with the source?

I had this problem too and banged my head against the wall for a long time.

Icons should be accessed through the classpath as you indicate.
This means they should be located in your _destination_ directory
(along with your .class files) on your development machine, and
be bundled into the .jar if that's how you deploy. Typically you
set Make or Ant or your IDE up so that it _copies_ images (or make
a symbolic link) from your source area to your destination area.

Code to access an image via classpath:

  URL url = getClass().getResource ("/com/company/path/icon.gif");
  ImageIcon icon = new ImageIcon (url);
  JLabel label = new JLabel (icon);

Beware: Don't use backslash in the path. This is *not* a file name
(even if it looks like that). It is a _resource_ and Java chose the
slash as a delimiter.

Also: Don't forget the initial "/". This is a common error. Probably
because "jar -tf" don't report it.

Note: Most often images are accessed from within the
_current_ package (that is at least how you should organize it; don't
have one single /com/company/images/ repository). In this case your
code will be easier to maintain if you pick the path name from the
current package rather then spelling it out explicitly.

Code:

  String fileName    = "icon.gif";
  String packageName = getClass().getPackage().getName();
  String resource    = "/" + packageName.replace('.','/') + "/" + fileName;
  URL url = ... // continue with the above

And even if you do have images elsewhere, access it via its package
as outlined here because hardcoding paths like "/com/company/..." breaks
down if your code undergo obfuscating, and: it is easier to move code
around without breaking it.

If you do choose to pick resource from a central repository, consider
making a dummy Java class (or interface) which can be used as a package
handle:

  import com.company.images.Images;
  :
  String packageName = Images.class.getPackage().getName();

"Images" should be as simple as this:

  package com.company.images;
  public interface Images{}

How are you invoking Java?

java -cp . TheMainClass

should add the current directory to the class-path
and the 'getResource' will work.

( But as Paul mentioned, ultimately it is better to jar
your project, that sugestion is simply to allow testing. )

For slightly more on finding resources, check this..
<http://www.physci.org/codes/javafaq.jsp#path>

HTH

..hmmm.  Poking your tongue out at somoene who is trying
to help you ..interesting strategy.

I expect Ike was thinking pretty much along these lines..
<sscce>
import javax.swing.*;
import java.awt.MediaTracker;

public class TestImage {
 public static void main(String[] args) {
   ImageIcon pic0 = new ImageIcon("pic0.jpg");
   JLabel pic0a;
    if(pic0.getImageLoadStatus() ==  MediaTracker.COMPLETE) {
     pic0a = new JLabel(pic0);  
     JPanel panel = new JPanel();
     panel.add(pic0a);
   }
 }
}
</sscce>

..but you need to find that image first, and there
are probably more constructive ways of doing that than
by poking your tongue out at those offering help.