Java J2EE Interview Questions and Answers

1. What do you understand by the term J2EE?
J2EE is a specification. provides middleware services.
EJB JDBC JNDI JMS JavaMail JTA Servlets JSPs Connectors JAAS

EJB : is Server Side component architecture for developing distributed
applications.
Developers need to concentrate only on business logic.
The middleware services are provided by appserver.
(transaction management,persistence, threading,concurreny )

Session Beans : Model processes
Entity Beans : Model data
Message Driven beans : Similar to session beans. Invoked only by
sending messages.

2. Diff between RMI and EJB

EJB uses RMI technology.
We have to declare the middleware services needed by the EJB in a
descriptor.
The Appserver will generate stubs for the same.

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