Java, anonymous inner class definition

It is an anonymous inner class. You can find some more information about it at the Java documentation link for Inner Classes. EDIT I am adding a better link describing anonymous inner classes, as the Java documentation leaves something to be desired. /EDIT

Most people will use Anonymous inner classes to define listeners on the fly. Consider this scenario:

I have a Button, and when I click it I want it to display something to the console. But I do not want to have to create a new class in a different file, and I don't want to have to define an inner class later in this file, I want the logic to be immediately available right here.

class Example {
    Button button = new SomeButton();

    public void example() {
        button.setOnClickListener(new OnClickListener() {
            public void onClick(SomeClickEvent clickEvent) {
                System.out.println("A click happened at " + clickEvent.getClickTime());
            }
        });
    }

    interface OnClickListener {
        void onClick(SomeClickEvent clickEvent);
    }

    interface Button {
        void setOnClickListener(OnClickListener ocl);
    }
}

The example is somewhat contrived and obviously not complete, but I think it gets the idea across.

What is happening in your code is that you are implicitly subclassing Apple with an anonymous inner class and overriding its toString() method.