What kind of convoluted servlet accepts plain ole XML but returns a soap message? I’ve never heard of that before. I guess asking for a WSDL that describes this service is out of the question, right?
So you need to send an xml file in the body of the post as well as two non-xml arguments? I don’t think a content-type of text/xml is correct for that arrangement since only one of the parms is XML.
This is a way weird implementation. I’m not sure how to advise you on this.
IMHO, if the servlet will return a soap message, it should accept one. If it is pretending to be a web service it should have a WSDL that describes it. If the service will accept XML doc only then you can use text/xml as the content-type. If the service needs to accept xml plus other args, text/xml is not correct.
If you are describing this correctly, it may be so screwed up that you’ll have to write a custom java service to do the post and force the content-type. Perhaps you could clarify with the developer / owner of the servlet, just how they intend for others to use their amazing service.