-----Original Message----- The content-length is passed in the response header. Therefore it cannot be set once you have written data to the response body (after all, the header is written before the body, for details see http spec).
If you know the length in advance you should set it (for example when streaming data from a file or from a BLOB field in a database). If you are generating data on the fly and cannot predict the length, simply do not call setContentLength. Your browser will still receive the file, it just won't show a download percentage as it does not know how much it will receive. Try it out with a few MB of data, you'll see what I mean. -----/Original Message----- The problem with the missing content-length is that certain browsers are tempted to redo the request, just because the length is missing... At least some reports on problems with double-requests from IE to PDF- producing servlets imply this... regards Alexander -----Original Message----- -----Oorspronkelijk bericht----- Van: CONNER, BRENDAN (SBCSI) [mailto:[EMAIL PROTECTED] Verzonden: dinsdag 25 oktober 2005 21:46 Aan: MyFaces Discussion Onderwerp: RE: AW: FileDownload capability? I think I have most of the answers to my own questions, after consulting the O'Reilly book "Java Servlet Programming": 1. The response, if set, has to be exact. However, it does not have to be set. Using it allows Servlets to be able to take advantage of persistent connections, if available. 2. It must be set before sending the response body. So, given this, does (2) above imply that, if done, setting the length has to precede the first write? Or it just has to be done before calling responseComplete()? - Brendan P.S. I realize this is more of a Servlet question than a MyFaces question. Sorry about that. -----Original Message----- From: CONNER, BRENDAN (SBCSI) Sent: Tuesday, October 25, 2005 2:38 PM To: 'MyFaces Discussion' Subject: RE: AW: FileDownload capability? In earlier examples, one had to call response.setContentLength() with the number of bytes being passed. I have the following questions regarding this: 1. What are the consequences if I get the length wrong? Does it have to be exact? 2. Can the setContentLength() be called after I have done all the writes, or must it be done before the writes? If I can call it beforehand, then I can compute the length as I go. Otherwise, it will be more difficult. Thanks, - Brendan -----Original Message----- From: CONNER, BRENDAN (SBCSI) Sent: Tuesday, October 25, 2005 12:15 PM To: 'MyFaces Discussion' Subject: RE: AW: FileDownload capability? And it's even easier if one is generating a text file (rather than a binary file), for example, when writing out a comma-separated file for use in a spreadsheet, since one can use response.getWriter().print(String s) and response.getWriter().println(String s). - Brendan -----Original Message----- From: Nico Krijnen [mailto:[EMAIL PROTECTED] Sent: Tuesday, October 25, 2005 3:00 AM To: 'MyFaces Discussion' Cc: [EMAIL PROTECTED] Subject: RE: AW: FileDownload capability? It is actualy much easier in JSF. You just need to have an action method in a (managed) bean, like this: public String downloadFile() { FacesContext facesContext = FacesContext.getCurrentInstance(); if (!facesContext.getResponseComplete()) { String fileName = "myfile.pdf"; ServletContext servletContext = (ServletContext) facesContext.getExternalContext().getContext(); String contentType = servletContext.getMimeType(fileName); HttpServletResponse response = (HttpServletResponse) facesContext.getExternalContext().getResponse(); response.setContentType(contentType); response.setHeader("Content-Disposition", "attachment;filename=\"" + fileName + "\""); try { InputStream in = /* get your data */; ServletOutputStream out = response.getOutputStream(); byte[] buf = new byte[512]; int bytesRead; while ((bytesRead = in.read(buf, 0, bufSize)) != -1) { out.write(buf, 0, bytesRead); } out.flush(); facesContext.responseComplete(); } catch (IOException e) { throw new RuntimeException(e); } } return null; } Then you can simply call the method from a commandLink or commandButton <h:commandLink action="#{yourBean.downloadFile}"> <h:outputText value="download" /> </h:commandLink> Nico -----Oorspronkelijk bericht----- Van: news [mailto:[EMAIL PROTECTED] Namens Werner Punz Verzonden: maandag 24 oktober 2005 23:34 Aan: [email protected] Onderwerp: Re: AW: FileDownload capability? It is rather easy, I usually have a download servlet for this which generates the appropriate html code, I do not have the code handy currently but you basically set the header mimetype to either your filetype or application/octed stream, then pass down the content length (this is important because otherwise our all beloved IE has some problems on certain filetypes) and then you basically pass the stream as content down as embedded binary data. You also can achieve that with a phaselistener if you feel uneasy to do it over a separate servlet. All you then have to do is to link to the servlet or phase listener with a linke and a target="_new" Werner [EMAIL PROTECTED] wrote: > I have nearly the same problem: > > I have the link of a sample file (pdf, doc or something else) in the database. > Now the user should have the possibility to open this file via a CommandButton or CommandLink > > I'm not quite sure, how I can do this? > Thx for help >
