What is the major difference SessionBean and EntityBean?

Answer Posted / sulthansheriff

In entity-bean , there are finder- method which are not in
session-bean
In entity-bean , CMR's are used , which are not there in
session-bean
----------------------------------------
Entity Beans
-------------
- represents an entity
- must have at least one finderXXX() method
- may or may not have create() or createXXX() methods
- when you call remove() on an entity bean the entity is
removed permanently but the bean instance goes back to the
pool it never die's.
- Entity beans home interface can have Home Business methods
- Entity beans home methods may or may not return component
interface object.
- Entity bean create() method creates a new row into the
database whereas create() method in session bean doesn't.
- Entity bean's finder method that returns a collection will
never throw a exception if it does not find related records
in the underlying persistent storage instead it will return
an empty collection.
- Entity beans will survive container crash as long as the
data is persisted in the underlying storage.
-----------------------------------------------------------
Session Bean
-------------
- generally they are used to perform some actions(verbs)
- there are two types of SB stateless and stateful.
- should have at least one create() "no args" constructor
(Stateless bean only)
- Stateless beans are more scalable then stateful beans.
- Stateless beans do not retain conversational state between
method invocations.
- Stateless beans are not tied to a particular client
whereas stateful beans are.
- The result of a client calling create() on home interface
of a stateless SB does not result into creation of a bean
but in stateful it does.
- There is no effect of calling remove() on Stateless
session bean because the beans go back to the pool after the
method call completes.
- session beans will never survive a container crash.

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