code: @Override
    public boolean doList(String path, ResourceFilter filter)
    {
      try
      {
        JarFile jarFile = new JarFile(_jarResource.getFile());
        try
        {
          return doList(path, filter, jarFile);
        }
        finally
        {
          jarFile.close();
        }
      }
      catch(IOException e)
      {
        if(log.isDebugEnabled())
          log.debug("exception (ignored) while listing path " + path, e);
  
        return false;
      }
    }
docs: If the path denotes a directory, then it will return all resources that are contained in the
  directory.
  
  @param path   the path to the resource (it already ends with /)
  @param filter the filter to include only some resources in the result
  @return <code>true</code> if it was a directory, <code>false</code> otherwise