interface - Overridden methods are not inherited

Question

I was reading Java SCJP book by Khalid A. Mughal (for JE6), and in topic 7.6 Interfaces and Page number 313, it is given that

A subinterface can override abstract method declarations from its superinterfaces. Overridden methods are not inherited.

I could not quite understand what "Overridden methods are not inherited." means. I tried to do this:

interface A
{
    void abc();
}

interface B extends A
{
    @Override
    void abc();
}

interface C extends B
{
    void abc();
}

And I did not get any error. What am I not understanding?

Answer 1

This simply means that overridden methods can have a slightly different signature than the superinterface's methods. For example:

public interface Foo {
    Object doSomething(String input) throws IOException;
}

public interface Bar extends Foo {
    @Override
    String doSomething(String input);
}

As you can see, in the subinterface, I no longer throw a checked exception, and I guarantee that the returned object is a more specific type. The method that did throw a checked exception is not inherited, because it is overridden.

---

I don't have the context of the entire paragraph, but there's something else related that applies only to implementations and not interfaces, which is that if you override a method without explicitly calling super, the superclass's implementation won't occur.

For example, if I have:

public class Example {
  public static class Foo {
    public void printSomething() {
      System.out.println("Foo");
    }
  }

  public static class Bar extends Foo {
    @Override
    public void printSomething() {
      System.out.println("Bar");
    }
  }

  public static void main(String[] args) {
    Bar bar = new Bar();
    bar.printSomething();
  }
}

This program will simply output:

Bar

but NOT Foo. If I add a call to super.printSomething(), then it will print both.