What is an EJB 2.1 CMP Entity Bean?
When you choose to have the container manage your persistent data for an entity bean, you define a container-managed persistence (CMP) entity bean. A CMP entity bean class is an abstract class (the container provides the implementation class that is used at runtime) whose persistent data is specified as container-managed persistence fields (see “What are Container-Managed Persistence Fields?”) for simple data or as container-managed relationship fields (see “What are Container-Managed Relationship Fields?”) for relationships with other CMP entity beans. In this case, you do not have to implement some of the callback methods to manage persistence for your bean’s data (see “What is the CMP Entity Bean Lifecycle?”), because the container stores and reloads your persistent data to and from the database. When you use container-managed persistence, the container invokes a persistence manager class that provides the persistence management business logic. OC4J uses the TopLink persistence mana
