what s the difference b/w EJB 2.0 and EJB 3.0 technically
- 2 Answers
- 24642 Views
- Microsoft, Mind Tree, Tech Mahindra, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / amar
The major differences i have seen between EJB 2.x and EJB
3.0 versions are as follows :-
1). Removal of home interface enabled simple lookup process
in ejb 3.0
2). EJB deployment descriptors are not required in ejb3.0
3). Annotations are used in ejb3.0
4). EJB 3.0 entity beans don’t have home and remote interfaces.
5). EJB 3.0 entity beans/JPA becomes local. Remote
annotations are not at all supported for entity beans.
6). EJB 3.0 beans don’t implement the standard interfaces
like javax.ejb.SessionBean and hence no need to implement
the container call back methods like ejbActivate() etc
7). Query is very flexible. Multiple levels of joins are
enabled through the refined EJB-QL
8). Can be used with pluggable third party persistence providers
9). Security can be provided either through annotations or
through deployment descriptors
10). POJO like EJB 3.0 entities become lightweight and easy
to convert from a DAO to Entity bean or vice versa. Since
EJB 3 entities don’t need implement any interface.
| Is This Answer Correct ? | 61 Yes | 7 No |
Answer / nidhi aggarwal
EJB 2.0 are very complex, difficult to learn/use. Uses
methods
like "ejbPassivate", "ejbActivate", "ejbLoad", "ejbStore".
Needs a deployment descriptor.
In EJB 3.0 methods
like "ejbPassivate", "ejbActivate", "ejbLoad", "ejbStore"
are removed. Annotations are provided. In EJB 3.0, we donot
need deployment descriptor. POJO(Plain old java object) are
introduced. For defining any relationship 1:1, 1:N, N:1,
M:N we have annitations.
| Is This Answer Correct ? | 42 Yes | 9 No |
How many enterprise beans?
Which is more beneficial: Stateful or Stateless Bean?
What is difference between stateless and stateful?
How can one EJB be called from within another EJB?
whatis the diff between ejb and servlet/jsp
What is ejb home object?
What are the design principles for ejb?
What is software architecture of ejb?
can we stop the execution of a method before completion?
Where a bean can be used ?
Can you be deported if you are stateless?
What is stateless session bean?
Core Java 
