I have been trying to figure this one out myself but had to turn elsewhere to get the answer.
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The relevant section of the JLS is in 6.3.1: "A declaration d of a type named n shadows the declarations of any other types named n that are in scope at the point where d occurs throughout the scope of d." In the top-level class Bar, the declaration of Foo.Bar is not in scope at the time that top-level Bar is declared. Therefore top-level Bar does not shadow Foo.Bar. However if we look inside the Foo class, top-level Bar is in scope at the time Foo.Bar is declared. (Bar is a public top-level class in the same package, so it's in scope.) Therefore by the rule quoted above, Foo.Bar shadows top-level Bar.
Normally, the way to access a shadowed name is by using a fully qualified name (i.e. include the packge name).
Unfortunately in your example we can't do that, as the classes are in the default package, which has no name, which means that the qualified name is unfortunately identical to the simple name, which means there is no way to refer to the shadowed top-level Bar instead of Foo.Bar.
If you put these classes in a package, the problem is easily solved:
code:
package simon;
public class Foo {
public static class Bar {
private int num = 0;
public void doIt() {
System.out.println("My number: " + num);
}
}
}
----
package simon;
public class Bar extends Foo {
public void doIt() {
System.out.println("Hello!");
}
public static void main(String[] args) {
simon.Bar myBar = new simon.Bar();
myBar.doIt();
}
}
Here "simon.Bar" clearly can only refer to top-level Bar. And if we wanted Foo.Bar instead, we could say simon.Foo.Bar, Foo.Bar, or just Bar. (The last would of course be a horrible idea at this point - the compiler would understand, but humans most likely be very confused (as we all have been).)
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