This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
If you're looking for help specifically with Struts, you should go to the Struts forum...
But this question really deals more with design of application flow rather than Struts directly - there are several choices you could make, depending on your application -
Restucture your application so that what is currently one form is spread across 3 real forms, save data in session on the server until all forms are filled in.
Write once, run anywhere, because there's nowhere to hide! - /. A.C.