Java: Casting Object to a generic type

Question

In Java when casting from an Object to other types, why does the second line produce a warning related to the cast, but the first one doesn\'t?

void a(Object o)          


        

Answer 1

Jon's answer is the right one, but occasionally you can't get around that warning (like when you're working with a legacy API). In those cases you can suppress the warning like so:

@SuppressWarnings("unchecked")
List list = (List) someApiThatReturnsNonGenericList();