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Multipart downloads

alix jermyn

Joined: May 05, 2010
Posts: 2


Users in our app can currently download a simple text file by clicking the appropriate button on a JSF page, the code snippet for which is shown below.
After their browser pops up the download window and the download is successful, their browser shows the same page they had before they clicked on the button.

Is it possible to send a multipart response back to the browser - containing the download, and the html for the next page they should see after the download?

--------------------- cleaned snippet for simple download, which works fine as it is -------------------------------
String exportedReport = generateReport();
bytes[] exportedBytes = exportedReport.getBytes();
String filename = "yourReport.txt";
FacesContext context = FacesContext.getCurrentInstance();
HttpServletResponse response = (HttpServletResponse) context.getExternalContext().getResponse();
response.setHeader("Content-Disposition", "attachment; filename=" + filename);
try {
Tim Holloway
Saloon Keeper

Joined: Jun 25, 2001
Posts: 17257

Unfortunately not. An HTTP response is basically just one "file". So if you send a document as a response, there's no place to hold the link. Web pages sidestep that problem by having embedded links to things like images which then download as separate request/response items, but that works because the HTML page renderer in the browser is designed to sense those links and make the requests. The general (non-HTML) processor doesn't do that.

You can return an HTML page that has multiple document links on it, which isn't the same thing, but at least it works. Or for that matter, you could simply have the server email a multi-part MIME document, although even there someone has to manually select where the different files in the email get broken out and under what names.

An IDE is no substitute for an Intelligent Developer.
It is sorta covered in the JavaRanch Style Guide.
subject: Multipart downloads
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