Java Reference
In-Depth Information
Figure 2-2.
Lightweight application architecture with the Spring Framework
Figure 2-2 shows a three-tier web application leveraging the different Spring Frame-
work modules. I will dissect each of the tiers to see how these modules are utilized and
what different options are available to build a flexible, simple enterprise Spring applica-
tion.
Presentation Tier
As the name suggests, Spring MVC provides first-class components to build web applica-
tions following the MVC pattern. Like any good web framework, Spring MVC helps build
the controller layer. It is flexible and supports a variety of components for view manage-
ment, including core Java EE technologies such as JSP and others such as Extensible
Stylesheet Language (XSL) and Portable Document Format (PDF).
As shown in Figure 2-2, the HTTP request from the client's web browser is first inter-
cepted by the controller component. This consists of a gateway servlet that acts as a
single entry point into the application. The servlet then delegates successive user
requests to respective handlers called
page controllers
. Page controllers are simple Java
classes that execute one application use case and invoke the business services. Spring
