Java Web Services: Up and Running, 2nd Edition

The RandService in Two Files

The RandService in the first example (see Example 4-1) combines, in a single source file, what JAX-WS calls the SEI (Service Endpoint Interface) and the SIB (Service Implementation Bean). The SEI specifies, at a high level that befits an interface, the service operations, and the SIB provides an implementation of the operations. A SIB can be one of the following:

• A POJO class such as RandService annotated as @WebService and encapsulating service operations, each annotated as a @WebMethod.
• A @Stateless Session EJB that is likewise annotated as a @WebService. EJBs in general predate JAX-WS; hence, this second type of SIB is an inviting way to expose legacy EJBs as web services.

Chapter 7 covers the EJB implementation of a @WebService. For now, the SIBs will be POJO classes. For convenience, most of my examples take the single-file approach, which combines the SEI and the SIB into one class annotated as a @WebService. The two-file approach is illustrated with the SEI RandService (see Example 4-4) in one file and the SIB RandImpl (see Example 4-5) in another file. The RandService is now an interface, whereas the RandImpl is a class that implements this interface.

Example 4-4. The Service Endpoint Interface for the revised RandService

package rand2;

import javax.jws.WebService;
import javax.jws.WebMethod;
import java.util.Random;

@WebService
public interface RandService {
    @WebMethod
    public int next1();
    @WebMethod
    public int[ ] nextN(final int n);
}

Example 4-5. The ...