1. What is EJB

EJB stands for Enterprise JavaBean and is a widely-adopted server side component architecture for J2EE. It enables rapid development of mission-critical application that are versatile, reusable and portable across middleware while protecting IT investment and preventing vendor lock-in.

2. What is session Facade?

Session Facade is a design pattern to access the Entity bean through local interface than accessing directly. It increases the performance over the network. In this case we call session bean which on turn call entity bean.

3. What is EJB role in J2EE?

EJB technology is the core of J2EE. It enables developers to write reusable and portable server-side business logic for the J2EE platform.

4. What is the difference between EJB and Java beans?

EJB is a specification for J2EE server, not a product; Java beans may be a graphical component in IDE.

5. What are the key features of the EJB technology?

1. EJB components are server-side components written entirely in the Java programming language
2. EJB components contain business logic only - no system-level programming & services, such as transactions, security, life-cycle, threading, persistence, etc. are automatically managed for the EJB component by the EJB server.
3. EJB architecture is inherently transactional, distributed, portable multi-tier, scalable and secure.
4. EJB components are fully portable across any EJB server and any OS.
5. EJB architecture is wire-protocol neutral--any protocol can be utilized like IIOP,JRMP, HTTP, DCOM,etc.

6. What are the key benefits of the EJB technology?

1. Rapid application development
2. Broad industry adoption
3. Application portability
4. Protection of IT investment