Today, you looked in more detail at J2EE and the facilities that it provides. You saw how the different J2EE technologies fit into the 3-tier model, and how it provides component frameworks for different types of functionality.
You have seen that the EJBs provide a robust, scalable home for business logic and that servlets (and JSPs) provide a flexible way of delivering application functionality to clients. There are many different types of client, ranging from simple, markup-based clients that work over HTTP to sophisticated and powerful clients that use GUIs and RPC.
You have seen that the creation and deployment of an enterprise application requires many different roles. You have also seen that an enterprise application is assembled ...