code: protected static String formatUserUrl(String username) {
          String url = USERS_MAPPING + USER_MAPPING;
          url = url.replaceAll("\\{username.*\\}", username);
          return url;
      }
docs: /*
  @ExceptionHandler(Exception.class)
  public ModelAndView handleException(Exception e) {
  setError(e);
  String username =
  SecurityContextHolder.getContext().getAuthentication().getName();
  return createRedirectMav(UserController.formatUserUrl(username));
  }