Download binary files

[mschmidke]

Currently, I am searching the forums how to serve downloadable binary data in a Seam application.

I found out so far that there are at least two possibilities:

1. By action as described in http://wiki.jboss.org/wiki/Wiki.jsp?page=SeamResourceLoader

2. By Seam's built in resource mechanism based on AbstractResource class.

Which way should I prefer? I think (2) is much more elegant, but I need to access my Persistence Context which does not seem to be possible (at least I do not understand enough of the BypassInterceptors-beginRequest-endRequest-stuff I copied from CaptchaImage :-) )


Marcus.

[mschmidke]

Hummm.

I removed the things I do not understand (as mentioned, beginRequest and endRequest). With this, I was able to remove BypassInterceptors, and without BypassInterceptors I can have injected my hibernate session.

At the first sight, it works perfectly. Of course, I don't know if I am breaking something in the interns of seam or if I am creating memory leaks or whatever.

@Startup
@Scope(ScopeType.APPLICATION)
@Name("dateidownload")
public class Dateidownload extends AbstractResource {
 @In
 Session session;

 @Override
 public void getResource(HttpServletRequest request,
 HttpServletResponse response) throws ServletException, IOException {
 // ServletLifecycle.beginRequest(request);
 try {
 String id = request.getQueryString();
 Anhang_Dokument ad = (Anhang_Dokument) session.get(
 Anhang_Dokument.class, Long.parseLong(id));
 if (ad == null)
 throw new ObjectNotFoundException(id);
 response.setHeader("Cache-Control", "no-store");
 response.setHeader("Pragma", "no-cache");
 response.setDateHeader("Expires", 0);
 response.setContentType(ad.getDatei().getMimeType());
 response.getOutputStream().write(ad.getDatei().getDaten());
 response.getOutputStream().flush();
 response.getOutputStream().close();
 } catch (Exception e) {
 response.sendError(HttpServletResponse.SC_NOT_FOUND);
 return;
 } finally {
 // ServletLifecycle.endRequest(request);
 }
}

 @Override
 public String getResourcePath() {
 return "/download";
 }

}

There are other things in CaptchaImage I don't understand, for example the meaning of @Startup and @Install together. But as told before, I simply deleted things I did not understand, and for the moment, it works ...


Marcus.