code: public static boolean isAllowed(ServletContext servletContext, ServletRequest request) {
  		return
  			Boolean.parseBoolean(servletContext.getInitParameter(ENABLE_INIT_PARAM))
  			&& isAllowedAddr(request.getRemoteAddr())
  		;
  	}
docs: Checks if the given request is allowed to open files on the server.
  The servlet init param must have it enabled, as well as be from an allowed IP.