Anonymous Inner classes and Final modifier [duplicate]

Question

To my understand correctly anonymous classes are always final:

This has been mentioned specifically in JLS 15.9.5

However, when i run the following code to check that it is showing that Inner class is not final.

    public class Test{
    static class A<T> {
    }
    public static void main(String arg[]) {
        A<Integer> obj = new A() {
        };
        if ((obj.getClass().getModifiers() & Modifier.FINAL) != 0) {
            System.out.println("It is a final  " + obj.getClass().getModifiers());
        } else {
            System.out.println("It is not final " + obj.getClass().getModifiers());
        }
    }
}

Output of above program is :

It is not final 0

Please clear my doubt as i am not able to understand this behavior.

Answer 1

I agree this may be considered a bug, given that other cases in the JLS exhibit a different behavior. Case in point is an interface: As per section 9.1.1.1:

Every interface is implicitly abstract.

And when running the below:

interface X {
    void foo();
}

public static void main(String arg[]) {
    System.out.println(Modifier.isAbstract(X.class.getModifiers()));
}

It returns true.

Another example is an enum where the JLS specifies:

An enum declaration is implicitly final unless it contains at least one enum constant that has a class body

And the below example is perfectly aligned with it.

enum X {

}

public static void main(String arg[]) {
    System.out.println(Modifier.isFinal(X.class.getModifiers()));  // true
}