Question

This code is invalid:

interface Foo
{
    public void foo(final String string);
}

public class Bar implements Foo
{
    // Error: does not override.
    @Override public void foo(final Object object)
    {
    }
}

Because every String is obviously an Object, I would expect this code to be perfectly fine: any code that depends on giving foo() a String would stil function when foo() actually takes an Object.

It appears, though, that method signatures have to be identical to those of the methods they’re overriding. Why?

Answer 1

What if

interface Foo
{
    void foo(String string);
    void foo(Object string);
}

Then which method is overridden by Bar?