Requirements of a JAX-WS Endpoint:-
JAX-WS endpoints must follow these requirements:
1 The implementing class must be annotated with either the javax.jws.WebService or javax.jws.WebServiceProvider annotation.
2 The implementing class may explicitly reference an SEI through the endpointInterface element of the @WebService annotation, but is not required to do so. If no endpointInterface is specified in @WebService, an SEI is implicitly defined for the implementing class.
3 The business methods of the implementing class must be public, and must not be declared static or final.
4 Business methods that are exposed to web service clients must be annotated with javax.jws.WebMethod.
5 Business methods that are exposed to web service clients must have JAXB-compatible parameters and return types.
6 The implementing class must not be declared final and must not be abstract.
7 The implementing class must have a default public constructor.
8 The implementing class must not define the finalize method.
9 The implementing class may use the javax.annotation.PostConstruct or javax.annotation.PreDestroy annotations on its methods for life cycle event callbacks.