In theory, theory and practice are the same. In practice, they are not.
How I do my little way:
1. Look at the WSDL schema data type: JAX-RPC and JAX-WS have some common data type. JAX-WS also support new data type which is
not supported by JAX-RPC. 1 of the link mentioned it.
2. Just do it by Nike:
I just take the wsdl and use JAX-RPC
soap engine to generate the client side to see if it complain or not.
if it complain, then provider use something NON JAX-RPC.
I just take the wsdl and use JAX-WS soap engine to generate the client side to see if it complain or not.
if it complain, then provider use something NON JAX-WS.
This exercise is to validate the point 1.