code: public void init(final FilterConfig filterConfig) {
  
          final String allowParam = filterConfig.getInitParameter("allowUrls");
          if (StringUtils.isNotBlank(allowParam)) {
              this.allowUrls = allowParam.split(",");
          }
  
      }
docs: Initialize "allowUrls" parameter from web.xml.
  
  @param filterConfig A filter configuration object used by a servlet container
  to pass information to a filter during initialization.