Oracle Service Bus: Content Type is defaulted to "mutlipart/related"

Question

I have scenario where I need to invoke a REST Webservice from OSB which accepts only media types which has "multipart/atom+xml". OSB is used for protocol transformation converting the SOAP request into the HTTP POST request with multipart. I have Proxy Service which will unwrap the message from the SOAP Body and post the message via Business Service and the attachment is passed 'as is' from the SOAP Service. The external REST Service Provider expects the media type to be "multipart/atom+xml", but in OSB when an attachment is present in the message, OSB is overrding the "Content-Type" property to "multipart/related" inspite of me setting the "Content-Type" property of HTTP Transport Header in OSB and as result external RESTFUL Service is throwing "415-Unsupported Media Type" error. Below is the test results. One interesting thing is, it happens only when there is attachment present in the message. In case of a message which doesn't have any attachment "Content-Type" specified in the Transport Header is passed by the OSB to the external service. Any help is highly appreciated.
OSB Transport Header
Added the header <http:Content-Type>multipart/atom+xml</http:Content-Type>
Actual Raw Message
POST http://xxx7200:7004/XXXInterfaces/identify HTTP/1.1
Content-Type: multipart/related; type="text/plain"; start="<Root_-328322390>"; boundary=MIME_Boundary; charset=UTF-8
MIME-Version: 1.0
User-Agent: Java1.6.0_17
Host: xxx7200:7004
Accept: text/html, image/gif, image/jpeg, /; q=.2
Proxy-Connection: Keep-Alive
Content-Length: 4823
Expected Raw Message
POST http://xxx7200:7004/XXXInterfaces/identify HTTP/1.1
Content-Type: multipart/atom+xml; boundary=MIME_Boundary;
User-Agent: Java1.6.0_17
Host: xxx7200:7004
Accept: text/html, image/gif, image/jpeg, /; q=.2
Proxy-Connection: Keep-Alive
Content-Length: 4803
-KC

Answer 1

There is no explicit option to disable the check on the XML content.
But the you can use Messaging Service of type Text request which will consider the data as string and so there will be no check.
If you want to use WSDL/AnyXML/AnySOAP proxies, the XML check is always carried when the $body varaible is not checked/modified when content streaming is enabled while creating the proxy. I'm quite sure HTTP transport supports content streaming and the stream from the input is directly given to BS with out realizing the XML. Only short coming is it should be a pure pass through and no data enrichment and any action in pipeline that requires realizing the XML from the stream.
Let me know if this helps.
Thanks
Manoj