J2EE Technologies

ABSTRACT

Traditional enterprise application providers have changed over from 2-tier, client-server application models to three-tier application models. The rapid development of this new model was fuelled by the introduction of various middleware services. A developer is usually faced with a range of problems while developing an enterprise-wide application. The different problem domains include the issues related to the productivity of the programming, maintenance of security, integration of new software with the existing systems. The purpose of J2EE is to provide the clients with secure, portable, platform independent, multi-user and an enterprise class platform that could be deployed on the server side writer in Java language.

J2EE Technologies

INTRODUCTION

Java Enterprise Edition, also known as Java EE or J2EE, exists as a set of specifications among many other specifications that are part of the Java Community Process (JCP). These specifications date back as early as 1998, when a public review and committee process was formed to add enhancements to the Java platform, J2EE is a framework that can be used to create n-tier, scalable, and distributed applications for use in large organizations, often where multiple users are accessing the same data concurrently. These are described as enterprise-level applications. Without a framework, developing such applications can be costly and time-consuming (Klemm, 2013). J2EE attempts to meet the needs of developers writing applications for this type of environment.

J2EE programming practices make use of the resource concept in order to provide several features to the application. In the case of JDBC, this allows a system administrator to configure database connections without modifying the application's source code or its embedded configuration files. Some application servers, such as GlassFish, provide a web-based interface to perform this sort of configuration. The web interface also allows an administrator to test the settings outside of the application (Krishnamurthy et.al, 2011). In addition, this system grants global scope to these objects either inside a web application or across the entire server. This provides the necessary scoping for objects that act in a shared fashion, such as JDBC connection pools, without the need for direct access of static objects by an application. Such objects can also be created using a singleton or factory pattern, where the implementations of these patterns are part of the server itself.

DISCUSSION

J2EE is equipped with a 3-tier model that is capable of supplying some of the most powerful features required in a large multi-user environment. This model incorporates concepts such as security, modularity, distribution, load balancing, and compatibility. This model generally assumes a networked environment containing one or more servers and clients, each of which may use different platforms and languages, as opposed to the mainframes of the previous generation. A web-based interface may be included, both for internal and external clients, but is not always used. Indeed, Java 2 EE supports the use of traditional desktop GUI applications as clients to its n-tier model (Johnson, & Stearns, 2002). The 3-tier model closely resembles the Model-View-Controller (MVC) architectural pattern, except that communication between the model and view is forced to ...