File download using RichFaces

Question

I got the following to work already:

1. User can upload a file (i.e. a compressed archive)
2. User can uncompress the file on the server
3. User can e

Answer 1

Your concrete problem is that you're attempting to download files by Ajax. This is not correct. JavaScript can't deal with binary responses nor has it any facilities to force a Save As dialogue. You need to make it a normal synchronous request instead so that it's the webbrowser itself who has to deal with it.

As to setting the content type, if you have a file name with extension at your hands, you could use ServletContext#getMimeType() to resolve it based on in web.xml (either the server's default one or your webapp's one).

ServletContext servletContext = (ServletContext) externalContext.getContext();
String contentType = servletContext.getMimeType(file.getName());

if (contentType == null) {
    contentType = "application/octet-stream";
}

response.setContentType(contentType);
// ...

(note that I assume that you're using JSF 1.x, seeing the way how you obtained the servlet response, you could since JSF 2.x otherwise also use ExternalContext#getMimeType())