Endpoint interface
A soap based web service can be implimented as a single java class.An endpoint interface, also known as a service endpoint interface (SEI), is a term used in Java Platform, Enterprise Edition when exposing Enterprise JavaBeans as a Web service (see also Service Implementation Bean (SIB)). It is annotated with @WebService and is a component interface, which declares all the abstract methods that are exposed to the client. As it extends the java.rmi.Remote interface, all methods must throw the RemoteException. A Web service client accesses a stateless session bean through the bean's Web service endpoint interface. Like a remote interface, a Web service endpoint interface defines the business methods of the bean.
In contrast to a remote interface, a Web service endpoint interface is not accompanied by a home interface, which defines the bean's life-cycle methods. The only methods of the bean that may be invoked by a Web service client are the business methods that are defined in the Web service endpoint interface.
The methods of an endpoint interface for a Web service are implemented in a session bean class that is stateless.