@Override
 public UrlContent execute(UrlContent content) throws CannotParserException {
   if (content.query == null) {
     return null;
   }
   String nav = StringUtil.getParameter(content.query, "nav");
   if (nav == null || !nav.startsWith("/")) {
     return null;
   }
   if (nav.endsWith(".jsp")) {
     nav = nav.substring(0, nav.length() - 4);
   }
   UrlContent result = UrlParser.parse(nav, content.custom);
   if (result == null) {
     return null;
   }
   content.module = result.module;
   content.path = ".index";
   content.query = null;
   return content;
 }