How to ensure completeness in an enum switch at compile time?

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In Effective Java, Joshua Bloch recommends creating an abstract method which would be implemented for each constant. For example:

enum Color {
    RED   { public String getName() {return "Red";} },
    GREEN { public String getName() {return "Green";} },
    BLUE  { public String getName() {return "Blue";} };
    public abstract String getName();
}

This would function as a safer switch, forcing you to implement the method if you add a new constant.

EDIT: To clear up some confusion, here’s the equivalent using a regular switch:

enum Color {
    RED, GREEN, BLUE;
    public String getName() {
        switch(this) {
            case RED:   return "Red";
            case GREEN: return "Green";
            case BLUE:  return "Blue";
            default: return null;
        }
    }
}

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