Re: Dynamic charts issues in batch PDF generation

[Clay Leeds]

On Jan 20, 2006, at 6:28 AM, Jeroen van der Vegt wrote: I'm not sure I correctly understand the problem anymore, but this might be relevant: Can't you let the JPEG servlet indicate that its output should not be cached? I use this code to disable various cache mechanism:    private void setNoCache(HttpServletResponse resp) {        resp.setHeader("Pragma","No-Cache");        resp.setHeader("Cache-Control","no-Cache");        resp.setDateHeader("Expires", 0 );    } Regards, Jeroen I understood the OP (pasted at the bottom of this msg) to mean there is a caching problem with the JPEG image of each chart. My previous post supported Jeremias 'simple' fix whereby each chart be given a different URI (PATH, name, etc.)--even if the difference is just 'dummy' text. I still believe this is the case. While you can set special caching parameters on the server end (such as described by Jeroen above), unless there is a change in the URI/PATH/Filename, there are other places where the file might be cached (thereby negating any 'NEVER CACHE THIS RESOURCE' settings). I attended a talk by Michael Radwin, Senior Engineering Manager for Yahoo, at ApacheCon US 2005 in San Diego[1], entitled 'HTTP Caching and Cache-busting for Content Publishers'. Among other things, Y! needs to ensure that multiple users at an Internet Cafe checking their mail will *never* receive the same content. On Jan 18, 2006, at 12:32 AM, vijay visu wrote: i am doing a code which generates the PDF in a batch process.  These PDFs include dynamically built charts by servlets.  I am making use of external-graphic tag to pick the images. These servlets throw jpeg image of the charts in the output stream. These servlets should be called for each PDFs generated since each chart will be unique. My problem is that the servlets which builds the dynamic charts are called  for the first time only. On the subsequent calls the old charts are  only built in PDF and the servlets are not getting called. Please help me out in this problem [1] (click on 'Cache-busting techniques' at the bottom of the navigation) http://public.yahoo.com/~radwin/talks/http-caching-apachecon2005.htm