I must admit, I'm a bit confused as to exactly what you're trying to do here. Some issues:
- If you want to use new Dice(), you need a Dice class. Where is it?
- If the Die2 class is supposed to represent a die, so that you can create several of them, then why are all the methods static? The class should have a non-static state (a private int upperFace would be fine), and then I'd expect most of the methods to refer to that state.
- You have (twice) declared UpperFace as a method-local variable, but then you're trying to refer to it in getUpperCase(). It's not visible there.
- You aren't consistent with your use of capitalisation. Following Java conventions, methods and variables should start with a lower-case letter
Here's one way of defining a simple Die class that could be used by your main class: