J2EE

The Java2 platform Enterprise Edition is a java environment for developing and deploying enterprise applications by providing set of services, API and protocols that provides functionality to develop multi-tiered applications and web based application.

J2EE architecture supports component based development of multitier application. J2EE applications mainly consist of following tiers:

Client Tier: It provide interface to middle tier through web components such as Servlets and JSP or standalone applications.

Middle Tier: Here the business logic of our application resides. Components in middle server consist of some of web services and enterprise beans. These components are installed on server inside J2EE Application server. It is a place where components perform actions.

Enterprise Data Tier: Enterprise data is stored over here, typically relational database.

The major technologies of J2EE are:

--Servlets.

--Java Server Pages (JSP).

--Java Database Connectivity (JDBC).

--Java Naming and Directory Interface (JNDI).

--Enterprise Java Bean (EJB).

--Extensible markup language (XML).

--Java Messaging Services (JMS).

--JavaMail.

--JAF (JavaBeans Activation Framework)

--Java IDL.

--Java RMI (Remote Method Invocation) / IIOP (Internet Inter-ORB Protocol).

--Java Transaction Service (JTS) and Java Transaction API (JTA)