Problem Posting MIME encoded attachment to Ariba Supplier Network

I'm having an issue with trying to use VB.NET and the WebRequest object to post some cXML text and an attachment. I believe I am formatting the text of the data I wish to post correctly, as it matches samples Ariba has supplied.

What I am uncertain of is if I am correctly using the WebRequest object to do the posting. I am setting the Method as "POST" and the ContentType as "multipart/mixed". I can successfully post cXML (using a ContentType of "text/xml"), so I know posting in general works.

The message I get back from Ariba is:

The document could not be parsed: Missing start boundary [ANCLS-741552]

However, as the following code shows, there is a start boundary. I have removed some proprietary data and replaced it with "...". Following the MIME text, I have included the relevant VB.NET code I am using.

Any and all suggestions are most welcome and appreciated!

------=_boundary.20100210154837663.173702
Content-Type: text/xml; charset=UTF-8
Content-ID: Part1.5213.20100210154837663.319349

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE cXML SYSTEM "http://xml.cxml.org/schemas/cXML/1.2.018/cXML.dtd">
<cXML.../cXML>

------=_boundary.20100210154837663.173702
Content-Type: application/octet-stream
Content-transfer-encoding: base64
Content-ID: 5213.20100210154837663.319349
Content-Disposition: attachment; filename=attachment_20100210154837663_125705.jpg
Content-Length: 5660

/9j/4AAQSkZJRgABAQAAAQABAAD/2wBDAAkGBwgHBgkIBwgKCgkLDRYPDQwMDRsUFRAWIB0iIiAd
.
.
.
dC2Nz9dOaQ1ZVIilwIpaWvLEg7aWuauv/9k=
------=_boundary.20100210154837663.173702--


Dim myWriter As StreamWriter = Nothing

Dim strUri As String = "https://service.ariba.com/service/transaction/cxml.asp"

Dim WebReq As WebRequest = System.Net.WebRequest.Create(strUri)

WebReq.Method = "POST"
WebReq.ContentType = "multipart/mixed"

myWriter = New StreamWriter(WebReq.GetRequestStream())
myWriter.Write(xmlText)
myWriter.Close()

Dim WebRsp As HttpWebResponse
WebRsp = CType(WebReq.GetResponse(), HttpWebResponse)

Solution

Bill - I got some info from Ariba and thought it might be useful to you:

The Content-type declaration for the whole payload specifies the boundary
Each part is preceded w/ a '--' followed by the boundary
The document terminates with a '--' followed by boundary followed by '--'
The Content-ID of each part is enclosed in angle brackets
The Content-ID of the attachment is referenced in the URL element in Comments/Attachment w/o angle brackets

Maybe you could try with a shorted boundary string. Also, note the 'start' parameter. Here's the one that worked for me:

request.ContentType =  "multipart/related;boundary=outerboundary1;type=""text/xml"";start=""<x.xml>"""

A sample XML with the above boundary & start settings looks like this:

--outerboundary1

Content-Type: text/xml

Content-ID: <x.xml>

<?xml version="1.0"?>

<!DOCTYPE cXML SYSTEM "http://xml.cxml.org/schemas/cXML/1.2.007/InvoiceDetail.dtd">

<cXML payloadID="za1saasxsx" timestamp="2003-04-04" xml:lang="en"><Header><From> 

... 

<Comments>These also use bluetooth<Attachment><URL>cid:[email protected]</URL></Attachment></Comments>

...

</Request></cXML>

--outerboundary1

Content-type: text/plain; charset=US-ASCII

Content-Disposition: attachment; filename=PremiereCatalog.xxx

Content-Length: 4

Content-ID: <[email protected]>

xxxx

--outerboundary1--

I know it can be very frustrating with very little help out there. So lemme know if you need the complete code that worked for me.

Pravin