2012 Latest EJB Interview Questions

1.        

2.       What is EJB

3.       Key Benefits of uisng EJB

4.       Different kinds of EJB

5.       What is Session Bean

6.       What is Entity Bean

7.       What is Message driven Bean

8.      What are the methods of Entity Bean?

9.       What are the callback methods in Entity beans?

10.   Can Entity Beans have no create() methods?

11.    How EJB Invocation happens?

12.    Is it possible to specify multiple JNDI names when deploying an EJB?

13.    How many types of protocol implementations does RMI have?

 

14.    Life cycle of EJB's

15.    Procedure for writing EJB's

16.    what are the call back methods in Session bean

17.    What are the call back methods in Entity bean

 

18.   Transaction models

19.    Transaction attributes?

20.   What is the default transaction attribute for an EJB?

 

21.    Can you create thread in EJB

22.   which one do you prefer to use HTTPSession or Stateful Session Bean

23.   Without looking at the deployment descriptor how can you say that ejb is stateful or stateless

24.   How can I pass init parameters to enterprise beans?

25.   Can I invoke Runtime.gc() in an EJB?

26.   Can a Session Bean be defined without ejbCreate() method?

27.   Marshalling and unmarshalling?

28.   What is lazy loading

29.   <ejb-link>

30.   Explain the directory structure of a enterprise application

31.    What are the various services provided by the EJB Container

32.   EJB QL

 

33.   How is Stateful Session bean maintain their states with client

34.   Architecture used by the passivation

35.   Architecture used by the activation

36.   Can you control when passivation occurs?

37.   what are the methods available in session synchronization

38.   Does Stateful Session bean support instance pooling?

39.   In Session Beans can I use BM and CM transaction at a time (NO)

40.   What is abstract schema

41.    Can I map more than one table in a CMP?

42.   Is it possible to update the Primary key of the entity bean

43.   What is a cmr-field. How can I differentiate between a cmr-field and a cmp-field?

44.   What is an ejbSelect() method?

1.       ejbSelect method(s) are not exposed to the client and the ejbSelect method(s) can return values that are defined as cmp-types or cmr-types.

45.   ejbSelect & find

 

Differences

1.       Instance Pooling & Instance Swapping

2.       ejbActivate & ejbPassivate

3.       ejbLoad & ejbStore

4.       EJB 1.1 and EJB 2.0

5.       CMP1.1 & 2.0

6.       local interface and remote interface

7.       Coarse grained & Fine grained

8.      BMP & CMP

9.       EJB Container & Web Container

10.   Application Server & Web Server

11.    sessioncontext and entitycontext

12.    optimistic locking and pessimistic locking

13.    ejbCreate() and ejbPostCreate().

14.    Servlet Sesison & EJB Session

15.    Container Managed Persitence 1.1 and 2.0

16.    ejbSelect vs finder methods

17.    Context, InitialContext and Session Context?

1.       Context is an interface that provides methods for binding a name to an object

2.       InitialContext is a Context and provides implementation for methods available in the Context interface

3.       SessionContext is an EJBContext object that is provided by the EJB container to a SessionBean in order for the SessionBean to access the information and/or services or the container

18.   Context, InitialContext and Session Context?