@SuppressWarnings for final type parameter

Question

In a place I have a method with a generic "VT extends String". Obviously this generates a warning: The type parameter VT should not be bounded by the final typ

Answer 1

Your code doesn't compile, but here's something similar, which I assume is what you want:

class A<T>{
    T value;
    B<? super T> b;
    void method(){
        b.method(value);
    }
}
interface B<X>{
    <VT extends X> VT method(VT p);
}
// works fine
class C implements B<Number>{
    public <VT extends Number> VT method(VT p){return p;}
}
// causes warning
class D implements B<String>{
    public <VT extends String> VT method(VT p){return p;}
}

Seeing that you don't have a choice to saying extends String here, I'd say this is a bug in Eclipse. Furthermore, Eclipse can usually suggest an appropriate SuppressWarnings, but doesn't here. (Another bug?)

What you can do is change the return and argument type to String and then suppress the (irrelevant) type safety warning it causes:

// no warnings
class D implements B<String>{
    @SuppressWarnings("unchecked")
    public String method(String p){return p;}
}