I have see this class BindingProvider in so may web service client as show below
what my question is How the object port is been cast to BindingProvider. the class SerPorttype is not even implementing the interface javax.xml.ws.BindingProvider
posted 2 years ago
Your SerPorttype is just an interface whose implementation is generated at runtime so the generated class could be implementing all sorts of interfaces.
Look up the proxy pattern (there are three types) to find out more about this use case.