UML State transition diagram for web apps

[Duncan]

If you are creating a state transition diagram to model a web app in Java, what would you normally be modelning the states of? THe controller servlet? For example, in an e-commerce app, multiple things are involved, likea login screen possibly, an online caatalog, a shopping cart, a payment, etc. Yet, except for the cart, and the controller servlet that manages the session, nothing else actually changes state. What would you model with such a diagram? Thanks.

[it career]

The shopping cart itself can have many states. Use MVC pattern.