EJB 2.0 introduces the local bean framework which is a nice way to model a relational database in objects. Local CMP (Container Managed Persistence) is even nicer for most applications. However, though this layer makes it easy to manipulate data in a database, it doesn't do a good job of making that data available to remote clients. Surprisingly, this is one of the problems that EJB was originally designed to deal with. There are a number of solutions to this remote interface problem, but one of the most common and the one I use in all of my development is the Session Facade pattern [Rules and Patterns for Session Facades].

Session Facade offers a number of nice features. For one, it is generally implemented as a stateless interface which greatly reduces the complexity of the server. Secondly, it allows business logic and other constraints to be maintained in the facade layer, insulating the data from unauthorized or undesirable access. Third, Session Facade provides the developer with fine grained control over the precise interface that is made available to the client. 9:35:12 AM    comment []