This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
When you enter text into a text-box, that text is represented as a String, always. You could write code that examines that String and decides whether it makes sense to parse that String into a Date, or an int, or some other type.