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Lesson 9

Entity Beans Architecture Conclusion

This module discussed entity beans and the architecture of the entity bean, including its many-to-one relationship with its client, its relationship with the underlying persistent data, and its identity.

Primary keys and instance identity

You were introduced to the concept of the primary key and shown how the primary key is used to find the bean and create the instance. You saw how the EJBObject is directly related to a single primary key.

BMP and CMP : Persistence

You were introduced to both bean-managed and container-managed persistence.

Container-managed beans are more portable but this requires a more sophisticated container. Bean-managed are less portable but will run in a very simple container. For container-managed persistence, you were introduced to simple mapping techniques between the bean and the data, or more complex schemes such as object relational mapping .

Entity bean lifecycle

You were introduced to the entity bean lifecycle, which allows the container to pool instances instead of discarding them. The EJBObject is permanently associated with the primary key, associated with the bean instance being created, or drawn from the pool when required.
The next module introduces the client side of entity beans.