Java EE At A Glance

 Java  EE ( Java  Platform, Enterprise Edition) is a platform for server  programming  using  Java   programming  language. Initially the platform was known as J2EE ( Java  2 Platform, Enterprise Edition) and was later known as  Java  EE. The latest version is known as  Java  EE 6. The new features of  Java  EE make it even more adaptable and make it easy to outsource  Java  development, for example. JavaEE APIs includes JDBC, RMI, email, JMS, Web services, XML among others. Features unique to Jave EE are Enterprise JavaBeans, Connectors, servlets, portlets, JavaServer Pages, etc., allowing portability and scalability of enterprise applications and also work with legacy systems enabling offshore  Java  development.

Overview

JavaEE allows developers to develop large, reliable, scalable and secure applications known as enterprise applications.These applications are used by large corporations to solve their IT problems. Increasingly,  Java  EE is also useful for individual developers and small organizations in this increasingly networked world where the norm is to outsource  Java  development. All these make  Java  Enterprise Edition complex. To simplify the enterprise application development, JavaEE comes with clearly demarcated functional segments like development model, API, and run-time environment otherwise called as multi-tiered where on every tier the developer concentrates on its own functionality. This modularity in approach helps to harness the full potential to offshore  Java  development.

Tiered applications

The application is split into multi-tiers depending on the functionality: a client tier, middle tier, and data tier. Development in particular tiers can be outsourced enabling a flexible approach to outsource  Java  development.

• Client tier: the client tier consists of an application like a Web browser, stand-alone application, or other servers running on a different machine from the  Java  EE server, which makes a request to the JavaEE server. The server receives the request, processes it, and returns a response back to the requesting application.


• Middle tier: the middle tier contains business functions that handle client requests and process application data. The components of the middle tier impart the business logic needed for an application. Business logic provides functionality to a particular business domain, e.g., financial industry, e-commerce. This tier contains the core functionality.


• Data tier: the data tier is also known as enterprise information systems. It contains enterprise resource planning systems, database servers and systems and a couple of legacy data sources. These data resources are typically stored in a system separate from the  Java  EE server.

 Java  Enterprise Edition servers

 Java  EE server helps in executing the APIs belonging to JavaEE platform and provides  Java  EE services. It is called as application server since it serves application data to clients, similar to a Web server that serves Web pages to Web browsers. The  Java  Enterprise Edition server provides services to various component types in the form of containers. To offshore  Java  development, a containerized architecture provides immense flexibility. The different containers are described below.

• JavaEE containers: these provide the interface between the lower-level functionality and the component and help in supporting the component.


• Web container: it provides an interface between web server and the web components.


• Application-side client container: it provides an interface between JavaEE application clients and the JavaEE server.


• EJB container: it provides an interface between enterprise beans and the  Java  Enterprise Edition server.

Requirements for  Java  EE

To get started on JavaEE development, programmers should install and configure their system ecosystem as given in the checklist below.

• Get  Java  EE 6 SDK


• Get NetBeans IDE and all necessary plugins


• Configure the environment

Source by Daniel Will