java filter jpg

Če je thumb, ne naredi nič, ga samo pošlje na klienta.

public void doFilter(ServletRequest req,
                         ServletResponse res,
                         FilterChain chain) throws IOException, ServletException
    {
         
if (request.getRequestURI().contains("_thumb.jpg"))
          {chain.doFilter(request, response);
...

Klient pa ignorira image cache, čeprav je slika iz istega naslova, ista datoteka, brez url parametrov, ...
Kajpak, druge slike na isti strani, ki ne gredo skozi filter, se keširajo.

Kako klienta prepričat da bi cache deloval ? Ali pa namesto "chain.doFilter(request, response)" kaj drugega ?

Ok, za gornji primer samo:

<filter>
  <filter-name>WatermarkFilter</filter-name>
  <filter-class>filters.WatermarkFilter</filter-class>
  <init-param>
    <param-name>Cache-Control</param-name>
    <param-value>max-age=3600000</param-value>
  </init-param>
 </filter>

in:

for (Enumeration e = fc.getInitParameterNames(); e.hasMoreElements();)
{
String headerName = (String)e.nextElement();
response.addHeader(headerName,
fc.getInitParameter(headerName));

}

pa je, kešira.


če pa iz filtra ven:

response.setHeader ( ....
.....

response.setContentType("image/jpg");
OutputStream os = response.getOutputStream();
ImageIO.write(buffer, "jpg", os);
os.close();

pa nikakor ne uspe. Sample link na ta način kjer cache ne dela (Firebug/net)