3.3 J2EE Platform Roles
Besides defining a standard blueprint for vendor neutral enterprise computing components, the J2EE specification identifies roles that participate in producing, creating, and supporting information systems built upon the J2EE platform. These roles as defined in the J2EE 1.3 specification are described in the sections which follow.
3.3.1 J2EE Product Provider
The role is responsible for providing the J2EE containers that house the specification components. In addition, they are required to provide deployment and management tools used to manage J2EE applications deployed to the product. IBM plays the role of a product provider with its WebSphere application server product.
3.3.2 Application Component Provider
This role identifies the provider of components such as enterprise bean developers, and HTML document designers, and programmers that create components used to produce J2EE applications. This book exists primarily to educate developers who will fill this role.
3.3.3 Application Assembler
The act of using J2EE components to construct an application is the role defined by the specificationan application developer. Assembly implies that components are created and defined within an Enterprise Archive (EAR) file for deployment to containers. We will discuss integrating J2EE components and packaging them as EAR files for deployment.
The deployer is responsible for deploying enterprise Java components into an operating environment that has a J2EE server supplied by a product provider. Deployment is typically made up of three steps: (1) installation, which involves moving the application (.ear) to the server environment; (2) configuration of any external dependencies required by the resource; (3) Execution of the installed application.
While our primary focus is application development, and not deployment, we will discuss areas where the two roles meet.
3.3.5 System Administrator
This role is not new to the J2EE landscape. Administrators are responsible for configuring and monitoring the operating environments where J2EE servers exist, tasks are accomplished by using the appropriate tools from the J2EE product provider. We will not examine this role in our book. For more information on performing system administration with the WebSphere family of products, see [Francis] or the WebSphere Application Server InfoCenter.
3.3.6 Tool Provider
Tool providers furnish tools that help with the construction, deployment, and management of J2EE components. Tools can be targeted to all platform roles defined by the specification. This book describes WebSphere Application Developer, used to develop components, making IBM a tool provider.
Currently, the specification does not require or provide a mechanism by which these tools are standardized. However, the specification has referenced a possibility of this being so in the future.