What happens when you have the same class twice in a war deployed in tomcat?

Question

What happens when you have the same compiled class twice in a war deployed in tomcat? (I know it's not a good practice and so on, but what happens behind the scene?)
Are there chances of nasty side-effects?

Answer 1

I would expect the behaviour is the same as anywhere else you have that situation.

The first class found by the class loader will be used, the other will be ignored.