JAX-WS endpoints must follow these requirements:
The implementing class must be annotated with either the javax.jws.WebService or javax.jws.WebServiceProvider annotation.
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.
The business methods of the implementing class must be public, and must not be declared static or final.
Business methods that are exposed to web service clients must be annotated with javax.jws.WebMethod.
Business methods that are exposed to web service clients must have JAXB-compatible parameters and return types. See JAXB default data type bindings.
The implementing class must not be declared final and must not be abstract.
The implementing class must have a default public constructor.
The implementing class must not define the finalize method.
The implementing class may use the javax.annotation.PostConstruct or javax.annotation.PreDestroy annotations on its methods for life cycle event callbacks.
The @PostConstruct method is called by the container before the implementing class begins responding to web service clients.
The @PreDestroy method is called by the container before the endpoint is removed from operation.