ATG Portal is implemented as a J2EE v.1.3 Web application, using Java Servlet Technology, v2.3 (Servlets). When a portal user enters the portal, an HTTP request is made to a Web server. The request is received by the Web server and handed off to the Portal container. The Portal container creates and initializes a portal context for the request. The Portal container may optionally authenticate the client and fire events or alerts.
The request is handled by a series of servlet filters known as the Portal Filter Chain. Each filter in the chain handles a specific task for the request and passes the request to the next filter. At the end of the Portal Filter Chain, the Portal request is dispatched to its target, typically a JSP or Servlet. The target servlet generates content to send back to the portal user via the response object, using Portal gears and other portal assets. (The process of rendering the page is covered in the Gears and the Portal Application Framework chapter.) Once the Portal container is finished with the response, control of the response is handed back to the Web server.
This chapter describes the Portal context, response and request and the Portal Filter Chain. It includes the following sections:
