QB - Jayaram College of Engineering and Technology

11. Why would a session bean use bean-managed transactions
In some situations, it's necessary for a (stateful) session bean to selectively
control which methods participate in transactions, and then take over the
bundling of operations that form a logical unit of work.
12. Is method overloading allowed in EJB
Yes you can overload methods.
13. How can JMS be used from EJB 1.1
The same as any client would use JMS. At this point there is no integration, but it
is planned for a future release of the EJB spec.
14. Can primary keys contain more than one field
Yes, a primary key can have as many fields as the developer feels is necessary,
just make sure that each field you specify as the primary key, you also specify a
matching field in the bean class. A primary key is simply one or more attributes
which uniquely identify a specific element in a database. Also, remember to
account for all fields in the equals() and hashCode() methods.
15. Which fields in beans should be public
All Container Managed Fields in an Entity Bean must be public.
Ejb 1.1 spec section 9.4.1 - "The fields must be defined in the entity bean class
as public, and must not be defined as transient."
16. How do I automatically generate primary keys
A common way to do it is to use a stateless session bean to retrieve the ID that
you wish to use as the primary key. This stateless session bean can then
execute an Oracle sequencer or procedure etc. to retrieve the ID value used as
the primary key.
17 What are the different type of Enterprise JavaBeans
There are 3 types of enterprise beans, namely: Session bean, Entity beans
and Message driven beans.
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