What you posted is WSDL. You can use that to create client-side classes that access the web service using the WSDL2Java tool that comes with Axis.
An easier way -since you already have the Calculator class as a JWS file in the axis directory- is to use the CalcClient class, which comes with Axis in the samples/userguide/Example2 directory. It demonstrates how to access the Calculator service.
I'm not sure why you're modifying a Struts config file - it has nothing to do with Axis.