When building IT systems, the functionality required of the application must be specified and the business objects within the domain must be identified. In “traditional” client/server systems, the application's functionality can be implemented in the front-end application or perhaps using database stored procedures, and the domain objects are usually tables within a database. In building an EJB-based system, the application's functionality corresponds to Session beans, and the business objects correspond to Entity beans.

You saw yesterday that Session beans take on the responsibility of implementing the application's business functionality. There will still be a presentation layer to display the state of those Session beans, but its ...

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