Why can enum implementations not access private fields in the enum class

Question

I just answered this question by saying how to solve the compilation problem:

How to use fields in java enum by overriding the method?

But what I don\'t unde

Answer 1

Your abstract class is not equivalent to your enum, since enums are implicitly public static final. Thus, you'll observe the same behavior if you use:

abstract class MyClass {

    static class FIRST extends MyClass {

        @Override
        public String doIt() {
            return "1: " + someField; // error
        }

    };

    static class SECOND extends MyClass {

        @Override
        public String doIt() {
            return "2: " + super.someField; // no error
        }

    };

    private String someField;

    public abstract String doIt();

}

As explained in http://docs.oracle.com/javase/tutorial/java/javaOO/nested.html, chapter "Static Nested Classes":

A static nested class cannot refer directly to instance variables or methods defined in its enclosing class: it can use them only through an object reference.

Thus the need of super. You could also use this if the field were protected rather than private.