Java Cart Flow

The cart uses MVC (Model - View - Controller) architecture, and always starts with ControllerServlet.java, which is of course the controller.
In the controller's servletContrext is caches information in several beans to reduce db io. The beans so far are: CategoryBean, ItemBean, ItemCategoryBean, and ItemInventoryBean.
The "ScreenWranglers" process the screens, processing the calling screen and setting up the next screen. When the controller is called in the processRequest() method it determines which screen was previously called in the current session by checking the session for it's "wrangler" atttibute. That wrangler is then called with it's calling data, any processing is done, the next scren needed is determined, and that screen's wrangler is called.
The appropriate JSP is then called by the controller servlet using a the RequestDispatcher. The JSPs used by the cart are quite simple, and meant to be heavily customized by any actual implementation.