HTTP header for dynamic pdf and IE6

I have a java web application that allows
an end-user in their browser to download
a "file", which happens to be bytes stored
in a database.

In experimenting with how to do this, I have
this snippet of code in my servlet:

            AttachmentListItem attachment =
             EmailSQL.getAttachmentListItem(connection, 3, 1);
            response.setContentType(attachment.getContentType());
            byte[] data =
             EmailSQL.getAttachmentBytes(connection, 3, 1);
            response.setContentLength(data.length);
            response.setHeader("Content-Disposition",
             "attachment; filename=\"" + attachment.getFileName() + "\"");
            ServletOutputStream out = response.getOutputStream();
            out.write(data);
            out.flush();
            out.close();

To test this out, I hit the link in my IE browser which brings up
a dialog box allowing me to "Open" or "Save" the file. If I save
the file, it does the right thing. If I press the open button, Acrobat
Reader opens up and then errors out with an alert box:
"There was an error opening the document. The file does not exist."

I have a yahoo email account that I tried a test on. I sent an email
message with the same pdf file attached to that account. I wanted to
see if yahoo figured out how to make this work. They did! (but I can't
figure out how to replicate)

Their header looks like this:
Date: Thu, 03 Jun 2004 15:37:58 GMT
P3P: policyref="http://p3p.yahoo.com/w3c/p3p.xml", CP="CAO DSP COR CUR
ADM DEV TAI PSA PSD IVAi IVDi CONi TELo OTPi OUR DELi SAMi OTRi UNRi
PUBi IND PHY ONL UNI PUR FIN COM NAV INT DEM CNT STA POL HEA PRE GOV"
Content-Disposition: attachment; filename=reference.pdf
Connection: close
Transfer-Encoding: chunked
Content-Type: application/pdf; filename="foo.bar"

.s4g--&v=1

There is also some other stuff I am seeing just after the header: .s4g-&v=1
which looks something like a query string, but I'm not sure.

My header looks like this:
HTTP/1.1 200 OK
Date: Thu, 03 Jun 2004 15:35:15 GMT
Server: Apache/2.0.40 (Red Hat Linux) mod_perl/1.99_07-dev Perl/v5.8.0
mod_jk/1.2.5 PHP/4.2.2 mod_python/3.0.1 Python/2.2.2 mod_ssl/2.0.40
OpenSSL/0.9.7a
Set-Cookie: JSESSIONID=DD3D0938B780EEBEBDC1B558CCBAD095; Path=/
Pragma: No-cache
Cache-Control: no-cache
Expires: Thu, 01 Jan 1970 00:00:00 GMT
Content-Disposition: attachment; filename="reference.pdf"
Content-Length: 214982
Keep-Alive: timeout=15, max=100
Connection: Keep-Alive
Content-Type: application/pdf;charset=UTF-8


Does anyone know how to work around this problem? I suppose
there are actually 2 parts to this:
1) What is the magic in the HTTP header that allows this to work?
2) How can one create such a header in java?

Thanks.
Dean Hoover

Received on Friday, 4 June 2004 08:28:54 UTC