The J2EE Connector Architecture and the J2EE Platform

The J2EE Connector Architecture is a specification contained within a much broader specification, known as Sun Microsystems' J2EE platform. It's important to understand exactly where the J2EE Connector Architecture fits within this larger scheme, especially in the area of component containers. J2EE specifies the use of containers to house elements. Client applications, servlets, JavaServer Pages (JSPs), Enterprise JavaBeans (EJBs), and resource adapters are all held in containers. The containers provide deployment and runtime support to the components residing within them. J2EE provides different kinds of containers depending on the type of support that the elements within them require. There are Web containers that host JSPs, servlets, and static HTML pages, EJB containers for EJBs, and application client containers that host standalone application clients. With the advent of the Java Connector Architecture, J2EE-compliant application servers have extended their support to include resource adapters that are hosted in connector containers. The containers themselves run in the context of an application server that provides additional transaction support. They can be monitored and administered through WebLogic Server's Administration Console.

The Java Connector Architecture, being a Sun Microsystems–proposed solution from its inception, was designed to draw heavily on the supporting infrastructure of the J2EE platform. It is built on top of and is intended to complement the J2EE specification—not to compete with it. The Java Connector Architecture fills a void that had heretofore been unaddressed by Sun. Issues related to integration with existing EIS systems were a notable omission from the original J2EE specification. The Java Connector Architecture remedies this by building on the component model and transaction and security infrastructures as they currently exist in the J2EE platform. From the beginning, BEA has sat on the expert group responsible for the Java Community Process associated with the development of this standard along with Sun, IBM, iPlanet, Netscape, Oracle, Motorola, and a few others. WebLogic's own implementation of the J2EE Connector Architecture standard represents a pure Java solution to the problem of EIS integration.

So far, there seems to be a wide acceptance for this technology. It has been adopted by many infrastructure vendors as a core part of their platforms and in some cases as their main solution for tying together Web-based and legacy systems. Some of the vendors incorporating the Java Connector Architecture into their product lines include BEA, iPlanet, SilverStream, IBM WebSphere, Oracle, Allaire, Borland, and HP.