Struts is a flexible control layer based on standard technologies like Java Filters, JavaBeans, ResourceBundles, Locales, and XML, as well as various OpenSymphony packages, like OGNL and XWork.
For the Model, the framework can interact with standard data access technologies, like JDBC and EJB, as well as most any third-party packages, like Cayenne, Hibernate, or iBATIS.
For the View, the framework works well with JavaServer Pages, including JSTL and JSF, as well as FreeMarker or Velocity Templates, PDF, XSLT, and other presentation systems.
Aside from actions and results, you can also specify exception handlers and interceptors. Interceptors specify the "request-processing lifecycle" for an action. (What happens to the request before and after the Action class fires.) You can specify both global and local lifecycles. If some of your actions respond to AJAX, SOAP, or JSF requests, you can simplify the lifecycle, and even just "pass through" the request, if you like.
The diagram describes the framework's architecture.
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