J2EE Architecture

What is J2EE?

JAVA 2 Enterprise Edition (J2EE) is java platform for enterprise applications development.

3-Tier Architecture

There are three layers in J2EE architecture

1. Application Layer - application layer is responsible for web components and user interface.
2. Business Logic (BL) Layer - BL Layer is responsible for decision making and transaction management.
3. Data Layer - DL is responsible for data manipulations.

J2EE Components

Following are the main components of J2EE ;

EJB Container

Enterprise Java Beans run within an EJB container. EJB container is a dynamic environment that is used to control the enterprise beans. EJB provides some important services that are compulsory for system.

The EJB container provides the following services to enterprise beans:

• • Business Deal Management
  • Security
  • Remote Connectivity
  • Database Connection Pool

Web Container

A dynamic environment that is used for JSP files and and servlets, is Web Container. These JSP files and servlets are known as web components, which are an important part of a J2EE application. All kind of user interfaces and request processing starts from web components.

Business Logic

All decision-making activities are performed within in Business Logic. Any other component cannot perform decision making or logical decision except BL.

Application Server

Application server like JBOSS or Websphere, is responsible to communicate with database server and web components.

Data Source

Data source is the actual data container. Database server is responsible for data source manipulations.