Explain J2EE architecture.

Answer

The JEE platform provides the environment to develop enterprise applications / services using multitier architecture. The highly intensified technology made the need for scalable, efficient, faster solutions for information management. The JEE technology is rightly apt for meeting these requirements. JEE provides a programming development environment which improves the productivity of development, standards for hosting / deploying enterprise applications.

The following are the tiers in JEE application

Client Tier: The client tier includes the web components such as Servlets, JSP or standalone Java Desktop applications. This tier provides dynamic interfaces to the middle tier.

• Middle Tier: This also called as the server tier. In the middle tier enterprise beans and web services encapsulate distributable business logic for the applications which are reusable. The JEE application server contains the server-tier components which provides the platform for these web components for actions to be performed and data to be stored / persisted.
• Enterprise data tier: The enterprise level data is stored / persisted preferably or typically in a relational database, in this tier.

The JEE applications comprises of components, containers and services. All the web components (Servlets, JSP) provide dynamic requests and responses from a web page. The EJB components contain the server-side business logic for enterprise applications.