Problems locating a texture

Hi everyone, I have made an object with blender and i have exported it to .obj format. It uses a texture named texture0.jpg, and i load the model by using this class:

public final class Model {
   public static Node load(String fileName) {
      Node loadedModel = null;
        URL model = Model.class.getClassLoader().getResource(fileName);
        // Set up the converter and convert it to jbin format
        FormatConverter converter = new ObjToJme();
        converter.setProperty("mtllib", model);
      converter.setProperty("texdir", model);
        ByteArrayOutputStream BO = new ByteArrayOutputStream();
        try {
            converter.convert(model.openStream(), BO);
            loadedModel = (Node) BinaryImporter.getInstance().load(new ByteArrayInputStream(BO.toByteArray()));
        } catch (IOException e) {
        return loadedModel;

Well, in the route i pass to the class there are, 3 files, one .obj, one .mtl and the .jpg, but when i compile the project i obtain this warning:
21-ago-2010 15:55:37 com.jme.util.resource.ResourceLocatorTool locateResource
ADVERTENCIA: Unable to locate: /home/antu/workspace/Compas/bin/res/cajon/texture0.jpg
But if i go to that folder, the file it is really there. What could be the problem?

I will show what i created with blender and what is shown by jme.

And this is my problem:

i added this and it seems the problem is gone but the box i see is black now.

 try {
                  new SimpleResourceLocator(Model.class.getClassLoader().getResource("res/cajon/")));
         } catch (URISyntaxException e) {

the texture is in the folder res/cajon/texture0.jpg.