Q: What are the different kinds of enterprise beans?
A: Different kind of enterrise beans are Stateless session bean, Stateful session bean, Entity bean, Message-driven bean.
Q: What is Session Bean?
A: A session bean is a non-persistent object that implements some business logic running on the server. One way to think of a session object.
Q: What is Entity Bean?
A: The entity bean is used to represent data in the database. It provides an object-oriented interface to .
Q: What are the methods of Entity Bean?
A: An entity bean consists of 4 groups of methods, create methods.
Q: What is the difference between Container-Managed Persistent (CMP) bean and Bean-Managed Persistent(BMP) ?
A: Container-managed persistence (CMP) and bean-managed persistence (BMP). With CMP, the container manages the persistence of the entity bean.
Q: What are the callback methods in Entity beans?
A: Callback methods allows the container to notify the bean of events in
its life cycle. The callback methods are defined in the javax.ejb.EntityBean interface.
Q: What is software architecture of EJB?
A: Session and Entity EJBs consist of 4 and 5 parts respectively, a remote interface.
Q: Can Entity Beans have no create() methods?
A: Yes. In some cases the data is inserted NOT using Java application
Q: What is bean managed transaction?
A: If a developer doesn't want a Container to manage transactions, it's possible to implement all database operations manually.
Q: What are transaction attributes?
A: The transaction attribute specifies how the Container must manage transactions for a method when a client invokes the method via the enterprise bean’s home.
Q: What are transaction isolation levels in EJB?
A: Transaction_read_uncommitted , Transaction_read_committed , Transaction_repeatable_read.
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