Java anonymous class and reachable private variable

Question

interface Test {
public void test();
}

public class TestMain {
private String h = "AAA";

public static void main(String[] args) {
    TestMain t = new TestMain();
}

public TestMain() {
    Test t = new Test() {
        public void test()  {
            System.out.println( h );
        }
    };

    t.test();
}

}

The above source works well.

But I think the variable 'h' should be unreachable from the anonymous class. I need to know why it works well.

Thank you for all of your help in advance!

Answer 1

Each instance of a non-static inner class has an enclosing instance -- an instance of the outer class which it tied to it via a reference variable stored in the inner class object. All the members of the enclosing instance of available to the inner class object via that reference.

The compiler takes care of adding that reference variable, of course, as well as some special accessor functions that the inner class object can use to get to the outer class object's private members. You can see these accessor functions by disassembling the outer class using javap -c.

Answer 2

The basic rule for determining accessibility to private members is, according to section 6.6.1 of the Java Language Specification:

[I]f the member or constructor is declared private, then access is permitted if and only if it occurs within the body of the top level class that encloses the declaration of the member or constructor.