you'll need to pass your modified response to service method of servlet which
is *in* the filterChain
ApplicationFilterChain::internalDoFilter(ServletRequest request,
ServletResponse response)
throws IOException, ServletException
{
............
servlet.service(request, response);
...........
}
Martin
> Date: Thu, 13 Mar 2014 17:51:59 -0700
> Subject: filter question
> From: catph...@catphive.net
> To: users@tomcat.apache.org
>
> I have a filter with doFilter method like this:
>
> public void doFilter(ServletRequest request,
> ServletResponse response,
> FilterChain chain)
> throws IOException, ServletException {
> HttpServletRequest req = (HttpServletRequest) request;
> HttpServletResponse resp = (HttpServletResponse) response;
>
> resp.setHeader("Cache-Control",
> "must-revalidate, max-age=0, post-check=0,
> pre-check=0");
>
> chain.doFilter(request, response);
> }
>
> This sets the header. However, if I set the header *after* chain.doFilter,
> the header is not set. Why is this?
>
> public void doFilter(ServletRequest request,
> ServletResponse response,
> FilterChain chain)
> throws IOException, ServletException {
> HttpServletRequest req = (HttpServletRequest) request;
> HttpServletResponse resp = (HttpServletResponse) response;
>
> chain.doFilter(request, response);
>
> resp.setHeader("Cache-Control",
> "must-revalidate, max-age=0, post-check=0,
> pre-check=0");
> }
>
> Programmatically I can see the header is null.
>
> Has the content already been sent to the web browser after chain.doFilter?
> If so, is there a way to delay sending data to the browser? I need to
> inspect the status code in the response before setting my header (to
> prevent 404's from being cached).
>
> Thanks,
> Brendan Miller
