code: protected boolean isRarFile(URL url)
     {
        if (url != null && url.toExternalForm().endsWith(".rar") && !url.toExternalForm().startsWith("jar"))
           return true;
  
        return false;
     }
docs: Does the URL represent a .rar file
  @param url The URL
  @return <code>true</code> if .rar file, otherwise <code>false</code>