Slightbook.com Slightbook.com

EJB interview questions


Total available count: 73
Subject - Java Technologies
Subsubject - EJB
1
Are Enterprise JavaBeans and JavaBeans the same thing?
2
Brief description about local interfaces?
3
Can a Session Bean be defined without ejbCreate() method?
4
Can beans use stored procedures in a database?
5
Can I develop an Entity Bean without implementing the create() method in the home interface?
6
Can I use Threads in a enterprise bean?
7
Can the primary key in the entity bean be a Java primitive type such as int?
8
Can you control when passivation occurs?
9
While deploying CMP entity beans, which fields in the bean are container-managed and how are they identified?
10
Does the EJB programming model support inheritance?
11
Do JTS implementations support nested transactions?
12
Explain the different Transaction Attributes and Isolation Levels with reference to a scenario?
13
For Entity Beans, What happens to an instance field not mapped to any persistent storage, when the bean is passivated?
14
How do enterprise beans access native libraries?
15
How does a client application create a transaction object?
16
How does an enterprise bean that uses container-managed transactions obtain a JTA UserTransaction object?
17
How does an entity bean obtain a JTA UserTransaction object?
18
How does a session bean obtain a JTA UserTransaction object?
19
How does EJB support polymorphism?
20
How does passivation work in stateful session beans?
21
How do I automatically generate primary keys?
22
How do you implement callbacks in EJB?
23
How EJB Invocation happens?
24
How is persistence implemented in enterprise beans?
25
How is the passivation of Entity beans Managed?
26
How many development roles are involved in J2EE application?
27
How should complex find operations be implemented?
28
How to implement an entity bean which the PrimaryKey is an auto numeric field?
29
If I throw a custom ApplicationException from a business method in Entity bean which is participating in a transaction, would the transaction be rolled back by container?
30
If my session bean with single method insert record into 2 entity beans, how can know that the process is done in same transaction (the attributes for these beans are Required)?
31
Is entity data persisted at the end of a transaction or at any time?
32
Is it legal to have static initializer blocks in EJB?
33
Is it possible for an EJB client to marshal an object of class java.lang.Class to an EJB?
34
Is it possible for a stateless session bean to employ a JTA UserTransaction object?
35
Is it possible to share an HttpSession between a JSP and EJB? What happens when I change a value in the HttpSession from inside an EJB?
36
Is it possible to stop the execution of a method before completion in a SessionBean?
37
Is there any default cache management system with Entity beans?
38
Static variables in EJB should not be relied upon as they may break in clusters. Why?
39
The EJB container implements the EJBHome and EJBObject classes. For every request from a unique client, does the container create a separate instance of the generated EJBHome and EJBObject classes?
40
What are Entity Bean and Session Bean?
41
What are the constraints or drawbacks of container managed EJB's?
42
What are the key benefits of the EJB technology?
43
What are the key features of the EJB technology?
44
What are the special design cares that must be taken when you work with local interfaces?
45
What classes does a client application need to access EJB?
46
What happens if remove( ) is never invoked on a session bean?
47
What happens when two users access an Entity Bean concurrently?
48
What is a Message Driven Bean, what functions does a message driven bean have and how do they work in collaboration with JMS?
49
What's an .ear file?
50
What is an EJB Context?
51
What is an EJB primary key? How is it implemented when the database doesn't have a primary key?
52
What is an enterprise bean?
53
What is clustering?
54
What is EJB?
55
What is Enterprise JavaBeans?
56
What is message-driven bean?
57
What is session Facade?
58
What is the advantage of putting an Entity Bean instance from the Ready State to Pooled State?
59
What is the advantage of using Entity bean for database operations, over directly using JDBC API to do database operations? When would I use one over the other?
60
What is the default transaction attribute for an EJB?
61
What is the difference between a Server, a Container, and a Connector?
62
What is the difference between Message Driven Beans and Stateless Session beans?
63
What is the difference between session and entity beans? When should I use one or the other?
64
What is the need of Remote and Home interface. Why can't it be in one?
65
What makes a Java class an enterprise bean?
66
What's different in Enterprise JavaBeans 1.1?
67
When should I adopt BMP and when I should use CMP?
68
Which fields in beans should be public?
69
Why an onMessage call in Message-driven bean is always a separate transaction?
70
Why are beans not allowed to create their own threads?
71
Why are ejbActivate() and ejbPassivate() included for stateless session bean even though they are never required as it is a no conversational bean?
72
Why do we have a remove method in both EJBHome and EJBObject?
73
Why is ejbFindByPrimaryKey mandatory?