Conveniently map between enum and int / String

Question

When working with variables/parameters that can only take a finite number of values, I try to always use Java\'s enum, as in

public enum BonusT         


        

Answer 1

Both the .ordinal() and values()[i] are unstable since they are dependent to the order of enums. Thus if you change the order of enums or add/delete some your program would break.

Here is a simple yet effective method to map between enum and int.

public enum Action {
    ROTATE_RIGHT(0), ROTATE_LEFT(1), RIGHT(2), LEFT(3), UP(4), DOWN(5);

    public final int id;
    Action(int id) {
        this.id = id;
    }

    public static Action get(int id){
        for (Action a: Action.values()) {
            if (a.id == id)
                return a;
        }
        throw new IllegalArgumentException("Invalid id");
    }
}

Applying it for strings shouldn't be difficult.