double brace initialization and "kind of" static anonymous class

Question

Sometimes for testing I use quick "double-brace" initialization which creates anonymous nested class in Outer class, for example:

static final Set<String> sSet1 = new HashSet<String>() {
    {
        add("string1");
        add("string2");
        // ...
    }
};

Edit I am correcting my previously faulty statement that this example keeps reference to Outer instance. It does not and it is effectively equivalent to the following :

static final Set<String> sSet2;
static {
    sSet2 = new HashSet<String>() {
        {
            add("string1");
            add("string2");
            // ...
        }
    };
}

both sSet1 and sSet2 are initialized with anonymous nested classes that keep no reference to Outer class.

Does it mean that these anonymous classes are essentially static nested classes ?

Answer 1

As in the related question you are referencing to is discussed, an anonymous class cannot be static technically, but it can be so called effectively static if it is declared in a static context, that is it has no reference to the outer instance.

In your case, however, there is definitely no difference between two approaches, the initialization of static fields is a static context as well.