Troubleshooting “The type parameter T is hiding the type T” warning

Do you somewhere have a class or interface named T, or are you using T as a concrete type name somewhere instead of as a type parameter (which means you might have forgotten somewhere else, for example in an enclosing class, to specify that T is a type parameter)? I can reproduce your problem with this:

class T {  // A concrete type T
}

interface B<T> {  // warning: The type parameter T is hiding the type T
}

interface A<T> extends B<T> {  // warning: The type parameter T is hiding the type T
    T getObject();
}

If I remove class T, it disappears.