Any difference in creating a web service from a java class or session bean?

Question

Hi,
The JDeveloper tutorial at http://www.oracle.com/technology/obe/obe1013jdev/10131/devdepandmanagingws/devdepandmanagingws.htm demonstrates creating a web service from a plain java class. I'm wondering:
- Is it possible to create a web service from a stateless session bean instead of a java class? If so, what's the proper way to do this in JDeveloper? When I tried doing so in JDeveloper 10.1.3.0.4 (SU5) using the J2EE Web Service wizard, the wizard did not list the session bean in the Component To Publish dropdown (it does list any java classes available in the project). I can proceed by manually typing in the name of the session bean. After the wizard completes though, the @Stateless annotation that had been in my session bean class code is removed and replaced by a @WebService annotation. The end result is that it looks like it made no difference whether I had tried to create the web service from a session bean or plain java class as the annotations in the resulting web service code are the same (although if I had started from a session bean, the class for the web service still implements the Local/Remote EJB interface that the session bean originally implemented).
- Assuming it's possible to create a web service from a stateless session bean, is there any advantage/disadvantage creating a web service from a java class vs a stateless session bean? I'm creating the web service from scratch so I also need to either build the java class or stateless session bean the web service would be based on from scratch too.
Thanks for any ideas about this.

Answer 1

Hi,
EJB Session beans (EJB 3.0) are deployed as WebServices by annotating the class with @WebService and the methds with @WebMethod (both tags require you to add the JSR-181 library to your project (available in the JDeveloper list of libraries)). Unlike the J2E WebService, the EJB session bean service is turned into a WebService upon deployment. This means you obtain teh WSDL file after deployment
- Assuming it's possible to create a web service from a stateless session bean, is there any advantage/disadvantage creating a web service from a java class vs a stateless session bean?
The difference is that EJB Session bean based web services are integrated with the J2EE container, which means that they can leverage container services like transaction handling, data sources, security, JMS etc.
Frank