More than a community and business event, Jazoon'08 offers you a chance to discuss technology free of pressure. You can meet the top evangelists and share with international developers your technical issues and questions - a pervasive brain storm about the Java platform. Excellent opportunity to validate your ideas on how to do better software - and if they don't survive the community's scrutiny, you can always blame the beers and back home with good learned lessons :). I have my own set of (Not So) Stupid Questions, and the first one I want to discuss with you is about web-services and EJB3.

Is it a good design to expose EJB3 Session Facade as web-services?

Reading patterns and examples on the Internet, EJB3 + @WebService seem to be a fast and furious way to go straight to SOA with few lines of code and a good container. Despite the simplicity of annotations, I started designing an Open Source Classifieds system based on J2EE technologies and I have some observations about that.

Instead of replicating here all discussions about web-services design and its technology support, I prefer to bring you a few design options and get your feedback live during Jazoon.

1. Web Client -> JAXWS SOAP web-services -> Session Facade -> Domain Model Facade -> @Entities
2. Web Client -> @WebService Session Facade -> Domain Model Facade -> @Entities
3. Web Client -> @WebService Session Facade -> @Entities

Some considerations about the above design options:

• If I use annotations, I am assuming SOAP web-services, right? And what about REST?
• If I do expose my Session Facade directly, how can I change later my interface from SOAP web-service to something else ?
• What about validation and security? My business component should care about data input validation and authorization and authentication?
• Load balance and orchestration. Can I use a web server (Tomcat?) to expose the service interface and a j2ee container to do the business? What about service collaboration? The session beans will have references one to each other?

Using a same class to expose services interface and realizing business use cases seems a bit overlapped to me, but eventually I am missing some point here. It is up to you, see you in Zürich :)