Java application clients accessing enterprise information system resources directly using JDBC and potentially even connectors in the future. In this scenario, presentation and business logic are by definition co-located on the client platform and may in fact be tightly integrated into a single application. This scenario collapses the middle tier into the client platform, and is essentially a client-server application scenario with the associated application distribution, maintenance, and scalability issues. Visual Basic clients consuming dynamic Web content, most likely in the form of XML data messages. In this scenario, the Web container is essentially handling XML transformations and providing Web connectivity to clients.
Presentation logic is assumed to be handled on the client tier.
The Web tier can be designated to handle business logic and directly access the enterprise information system resources. Ideally, the business logic is pushed back onto the EJB server, where the rich component model can be fully leveraged. The point is that it is important to use appropriate tools for a given problem space. Figure 1.7 provides a closer look at the Web container in a Web application scenario. It is important to keep in mind that the term Web container is being used here in a very precise way.