Serving large files for download using JSF

Question

Hello Community,
my JSF Controler Bean has a method which is called using method binding on either a commandButton or commandLink. It's purpose is to stream CSV datasets from a database to the browser, which then opens an application like ms excel, oocalc or gnumeric. Everything works fine if there is only a small number of datasets. But if there are several thousand datasets I get an OutOfMemoryError. So it seems that the data is somehow cached/buffered by the JSF Servlet. Is there a known workaround to my problem?
public void exportFile() {
        FacesContext context = FacesContext.getCurrentInstance();
        HttpServletResponse response =
(HttpServletResponse)context.getExternalContext().getResponse();
        response.setContentType("text/csv");
        response.setHeader("Content-disposition",
"attachment; filename=data.csv");
        try {
                 * This method iterates a java.sql.ResultSet and writes the data
                 * to the ServletOutputStream: "Write and Forget"
                writeData(response.getOutputStream());   // <<< If there are many datasets an OutOfMemoryError is produced
                response.getOutputStream().flush();
                response.getOutputStream().close();
                context.responseComplete();
        } catch (IOException e) {
                e.printStackTrace();
}Thanks, Alexander

Answer 1

Chrisse-
Ann is one of the most knowledgeable Photoshop folks here and I respect her immensely. However she comes from a long film background and is brand new to quality digital camera capture. Ann is
incorrect when she says
>I think that it is probably a toss-up between which would be worse: an interpolated rez-up or a 170 ppi print. Basically, Chrisse needs a better camera if she wants to make prints of this size let alone 11" x 14" ones.
Ann speaks from very extensive film-scan experience, but the reality is that "uprezzing" digital camera image capture is a whole different thing than uprezzing scanned film images. Those of us who do have substantial digicam experience have found a surprising ability to successfully uprez digicam image captures.
Certainly,
well-shot pix from your G9 will normally uprez to print 8x10s just fine and probably 11x14s as well.
Do not hesitate to experiment with uprezzing digicam captures - - including very large amounts of uprez like 2x or more. Test - test - test because each image and how presented/used is different.
I have found however that "well-shot," especially as regards exposure and focus, is important to allow good uprez. Also be especially careful with post-process edits because uprezzing can exacerbate editing distortion.
You need not worry about whether Ann is correct or I am - - just do it and judge the results. Do to typical viewing distances personally I use 300-360 ppi for small prints, 240-300 ppi for 8x10 and 240 ppi for 11x14; 180 ppi for large posters. But like others have said, if the ppi comes reasonably close at your chosen image size do not force a recalculation to reach precisely 240 ppi or whatever, just leave the resample box unchecked.