You can use the SOAP domain as a common WSDL-based logical tree format for working with Web services, independent of the physical bitstream format.
Messages in this domain are processed by the SOAP parser. The SOAP parser creates a common logical tree representation for all SOAP-based Web services and validates the message against a WSDL definition. If a runtime message is not allowed by the WSDL, an exception is thrown, otherwise the portType and operation names from the WSDL are saved in the logical tree.
You use the SOAP parser, normally, in conjunction with the SOAP nodes. In this context, the SOAP parser is always invoked in conjunction with the Java Axis2 pipeline and an external Web service interaction. Consequently, whilst most parsers read to and write from a bitstream, the SOAP parser is designed to work with interfaces provided by Axis2.
The SOAP domain offers WS-* processing, together with a canonical tree shape that is independent of the wire format (XML or MIME).
Specifically, this means that a WSDL 1.1 definition can be deployed to describe the Web service messages that the SOAP domain needs to parse and write at runtime. The bitstream format for these runtime messages can be SOAP 1.1 or SOAP 1.2, optionally wrapped by MIME as an SwA (SOAP with Attachments) or MTOM message.