Invoking a method of an anonymous class

Question

I learned the other day that you can do this

new Object() {
    void hello() {
        System.out.println(\"Hello World!\");
    }
}.hello();

Answer 1

As posted, there isn't a way to get the anonymous methods from the Object instance. And, it makes Anonymous classes look pointless. But, you could (and I usually would) use it to implement an interface. Something like,

static interface Hello {
    void hello();
}
public static void main(String[] args) {
    Hello o = new Hello() {
        public void hello() {
            System.out.println("Hello World!");
        }
    };
    o.hello();
}

Or, more commonly, for call-backs with JFC/Swing and ActionListener.