Here is a link that helped me with the Apache CXF client capabilities. The requirement was to send a request to a web service which required a SOAP Header expressing authentication information. The WSDL for the Web Service did not express the request in the abstract portion but rather in the binding/concrete portion of the WSDL. Apache CXF generated a class to support the setting of the Authentication Header but no methods to add it to the request. Using Google and a decent portion of scanning/reading, I found that Apache CXF will not generate the appropriate methods to attach a SOAP Header. Java Annotations provided the answer as described at:
By adding an annotation @WebParam along with the header=true flag and other appropriate values in the generated <####>SOAP.java as well as instantiating the Authentication Header via the generated class inside the <####>SOAP_Client.java, the client was sending a SOAP Header to the destination service.