25+ EJB Interview Questions

25+ EJB Interview Questions

EJB Interview Questions

1) What is EJB? 

EJB represents Enterprise Java Bean. It is a server-side part to create versatile, strong and verified endeavor applications in java.

2) What are the kinds of Enterprise Bean? 

There are three kinds of big business bean in java.

Session Bean

Message Driven Bean

Substance Bean

3) What is session bean? 

Session Bean epitomizes business rationale. It very well may be conjured by nearby, remote or web administration customer.

There are 3 kinds of session bean.

Stateless Session Bean

Stateful Session Bean

Singleton Session Bean

4) What is stateless session bean? 

A Stateless session bean is a business object that doesn't keep up the conversational state with the customer.

5) Write down the means for the formation of stateless EJB. 

Make a neighborhood interface.

The interface is to be utilized by the customer application.

On the off chance that the EJB customer condition is the equivalent, use @Local comment.

On the off chance that the EJB customer condition is unique, use @Remote comment.

Make a stateful session bean.

To imply a stateful bean, utilize @Stateful comment.

6) What is stateful session bean? 

A Stateful session bean is a business object that keeps up the conversational state with the customer.

7) What is singleton session bean? 

Singleton session bean is instantiated once for the application. It exists for the existence cycle of the application.

8) What is JMS? 

Java Message Service is an informing administration to make, send and get messages nonconcurrently.

9) What are the upsides of JMS? 

Offbeat

Dependable

10) What is PTP display? 

In Point to Point demonstrate, one message is conveyed to one beneficiary as it were. Here, Queue is utilized as a message-situated middleware.

11) What is Pub/Sub demonstrate? 

In the Publisher/Subscriber show, one message is conveyed to all supporters. Here, Topic is utilized as a message-arranged middleware.

12) What is MDB? 

Message Driven Bean (MDB) epitomizes business rationale. It is summoned by passing the message. It resembles JMS recipient.

13) What is Entity Bean? 

Substance Bean is a server-side segment that speaks to the determined information. Since EJB 3.x, it is supplanted by JPA.

14) What is Session Facade? 

Session Facade is a structure example to get to big business bean through the neighborhood interface. It abstracts the business object communications and gives an administration layer. It makes the execution quick over the system.

15) List some key performers in industriousness API. 

A portion of the key performers in industriousness API are:

Element

EntityManager

Perseverance unit

Information source

16) List down the means for the show of EJP industriousness component. 

Make a database table

Make element classes for the table

Make persevering unit and information source

Make a stateless EJB

Update stateless EJBM

Comfort based application gets to the stateless EJB.

17) Name the characteristics of javax.ejb.Stateful. 

Name

mappedName

Portrayal

18) Name the characteristics of javax.ejb.EJB. 

beanInterface

beanName

mappedName

19) Mention the three dimensions for applying interceptor strategies. 

Default

Class

Technique

20 Mention the Java types that can be mapped utilizing the @Lob explanation. 

java.sql.Blob

String

byte[]

java.sql.Clob

Serializable Object

21) Name the ACID properties of an exchange. 

Nuclear

Predictable

Disconnected

Solid