J2EE.2.2 Product Requirements

This specification doesn't require that a J2EE product be implemented by a single program, a single server, or even a single machine. In general, this specification doesn't describe the partitioning of services or functions between machines, servers, processes, etc. As long as the requirements in this specification are met, J2EE product providers can partition the functionality however they see fit. A J2EE product must be able to deploy application components that execute with the semantics described by this specification.

A very simple J2EE product might be provided as a single Java virtual machine that supports applets, web components, and enterprise beans simultaneously in one container (although this would be an extreme, and probably rare, case), and application clients each in their own container. A typical low end J2EE product will support applets in one of the popular browsers, application clients each in their own Java virtual machine, and will provide a single server that supports both web components and enterprise beans. A high end J2EE product might split the server components into multiple servers, each of which can be distributed and load-balanced across a collection of machines. This specification does not prescribe or preclude any of these configurations.

In addition, this specification does not describe which of the components that make up a J2EE product must be packaged together in a single product. A vendor of a fully integrated J2EE product might provide a complete package that includes all the software required to provide the J2EE services as well as the underlying operating system and even hardware. A more typical J2EE product provider might provide a middleware application server along with components that allow the server to integrate with products from other vendors (e.g., a database, a web server) to provide the complete J2EE product. Some vendors may require that the end customer purchase and integrate significant additional components to create a J2EE product. This specification does not prescribe or preclude any of these approaches. In all cases, it is the responsibility of the J2EE product provider to describe to the customer exactly what to do to create an environment that is J2EE-compatible.

A wide variety of J2EE product configurations and implementations , all of which meet the requirements of this specification, are possible. A portable J2EE application will function correctly when successfully deployed in any of these products.