code: @Override
      protected void initFilterBean() throws ServletException {
          if (this.resourcesElementsProvider == null) {
              final ServletContext servletContext = this.getServletContext();
              this.resourcesElementsProvider = ResourcesElementsProviderUtils.getOrCreateResourcesElementsProvider(servletContext);
          }
      }
docs: /* (non-Javadoc)
  @see org.springframework.web.filter.GenericFilterBean#initFilterBean()