Possible Duplicate:
Java – why no return type based method overloading?
The compiler does not consider return
type when differentiating methods, so
you cannot declare two methods with
the same signature even if they have a
different return type.
Java Tutorial
Why is this?
Because it’s not required to assign the result when you want to execute a method. How would the compiler then know which of the overloaded ones you’d like to call? There will be ambiguity.