Saif,
Sorry for the delayed response.
Are you developing your WS using an existing WSDL file (top down) or are you using exising Java Classes (bottom up)?
If you’re working bottom up, you just create a method which returns the object you desire, and in most cases the XFire Aegis binding should take care of this case.
More details about bindings are available here: Bindings Aegis Bindings
Let us know if you require further assistance.