J2EE provides an enviornment for developing Servlet and EJB applications, according to the Servlet and EJB spec. It also involves a number of server implemented services, such as JNDI, and standard protocols, such as https and RMI/IIOP.
Developing enterprise applications is a difficult and daunting task. A typical enterprise application must interact with a variety of complex data systems, including message queues, databases and people management software.
They must also support a variety of different client types, such as stand alone applications that run on a desktop computer, or applications that use an Internet web browser as their user interface.
J2EE is the Java 2 Enterprise Edition, and it is designed to help facilitate the development of sturdy, scalable and bulletproof enterprise applications.
F J2EE is a specification. F J2EE is a philosophy.
J2EE is a framework for building and deploying enterprise scale applications.
J2EE is a specification managed by Sun Microsystems, although all of the big players in the Java middle-tier market, such as WebLogic and IBM, contribute to the development and evolution of the spec.
The J2EE specification outlines how a developer should go about developing an enterprise application, and it defines a variety of services that a vendor, such as IBM, must implement if they want to advertise a J2EE certified application server.
The WebSphere Application Server is IBM�s certified, J2EE runtime environment.
J2EE is a complex monster, and any attempt to capture what J2EE is must start by breaking it down into its three very distinct parts:
F The components we create and subsequently deploy to a J2EE Application Server F The services a J2EE certified Application Server will provide to our components F The protocols used by clients to interact with our J2EE components