Overriding generic methods with non-generic implementations

Question

I\'m experimenting with generics in Java, and thought of this example.

If I have ClassA, I can override it with a subclass that references a co

Answer 1

Thanks to type erasure, this:

public  void doSomething(T data);

Really means this:

public void doSomething(Object data);

So no, there isn't a way to override with a more restrictive parameter type.

Also in this code:

class ClassA {
    public  void doSomething(T data) {};
}

The type parameter in your class name and the type parameter in the method are actually different parameters. It's like declaring a local variable of the same name as a variable in a higher scope. You can call doSomething(123) on an instance of ClassA because the second T is local to the method.