Re: encrypted javamail MimeMultipart

From:

Martin Gregorie <martin@address-in-sig.invalid>

Newsgroups:

comp.lang.java.programmer

Date:

Sun, 13 Jun 2010 16:20:27 +0000 (UTC)

Message-ID:

<hv30gb$5vg$1@localhost.localdomain>

On Sun, 13 Jun 2010 05:31:25 -0700, eunever32@yahoo.co.uk wrote:

On Jun 11, 7:22??pm, Martin Gregorie <mar...@address-in-sig.invalid>
wrote:

On Fri, 11 Jun 2010 06:53:14 -0700, euneve...@yahoo.co.uk wrote:

(4) should become:
?? ?? - create a ByteArrayInputStream from the decrypted byte
?? ?? array - pass that to a MimeMessage constructor.

?? ?? At this point you can use the standard MimeMessage and
?? ?? MultiPart methods to parse the message and extract its
?? ?? content.

Sorry for all the repeats - the NNTP server I use threw a wobbly this
morning and I hadn't realised it was accepting the post *and then*
locking up until just now.

Thanks Martin but maybe you can help me:

As I said I'm new to this Javamail api and am looking for a succinct
way to obtain the attachment

I can do

MimeMessage msg = new MimeMessage(session, new
FileInputStream("file.txt"));

The resulting msg has three headers which looks right

But when I do
if (msg.getContent() instanceof Multipart) {
?? ?? ??saveAttachment

}

True enough: MimeMessage.getContent() can return a lot of things
including InputStreams - thats why it returns an Object!

Did you do what I suggested and download both the JavaMail Design
Specification and the API Documentation? If not, go get them now and
read them. The first example in Design Specification Appendix B shows
exactly how to parse a multipart MIME message.

The Appendix B examples are all available as downloadable source code,
so you can run them and/or swipe useful code from them.

--
martin@ ?? | Martin Gregorie
gregorie. | Essex, UK
org ?? ?? ?? |- Hide quoted text -

- Show quoted text -

Martin

Thanks for your suggestion and I have obtained the Javamail Design
document you describe.
It is very good and I now know about Message, Part, MimePart,
MimeMultipart, MimeMessage and I can see there is an example of how to
read attachments.
I am not at my desk right now so I can't verify it however I am
concerned that if I do the following:

Object content = decryptContent(message, key, publicKey); And then I try

if (content instanceof MimePart) {
    ...
}
if (content instanceof MimeMultiPart) {
    ...
}
if (content instanceof InputStream) {
    ...
}

And if my code finds itself in "InputStream" then I am back to square
one (?)
And how then do I obtain the attachment which I clearly have

That depends what you want to do with it - you can read the InputStream
into an array, write it to a file,.... whatever your application requires.
You should, of course, be looking at the Part's headers to see what
you've got (and hence how you need to handle it) begoe doing anything
with the content. And don't forget that a MIME message is a recursive
structure. It may simply have a String as its root node (it its a simple
plain text message), but OTOH it might contain a MIME message which
contains one or more MIME messages as their attachments, which in turn....

--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |