This article (in dutch) describes how you can use UML Statechart diagrams to model pageflow in a web application. I’ve also describes how to integrate struts actions into the diagrams. I’ve kept it very simple, without stereotypes, to focus more on the communication part of the model. Ofcourse when you start to use generators, such as andromda, you can add stereotypes to instruct the generators how to generate the code.
One issue i raised is that, eventhough you can use statecharts to model pageflow, you have to be carefull that you don’t implement a too rigid statemachine when you implement the flow. It is usuallly desireable to have multiple entry points into one flow (usually you’ll have one flow per use case), to enable user to bookmark interesting pages, and to enable easy integration between multiple web applications.
One more point to raise here, activity diagrams are probably better to model pageflow than statecharts. I think statechart are more designed to model the state transitions within one object, whereas activity diagrams are designed to model the flow within a process. JDeveloper 10G will actually use activity diagrams to model pageflow.