public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest httpRequest = (HttpServletRequest) request;
// do not use the filter if this is a server-side include, JSP, or image file
if (httpRequest.getAttribute(INCLUDE_REQUEST_URI_ATTRIBUTE) == null
&& (!isExcludedFileExtension(httpRequest.getPathInfo()))) {
super.doFilter(request, response, chain);
} else {
chain.doFilter(request, response);
}
}
