Case-insensitive matching of a string to a Java enum

Question

Java provides a valueOf() method for every Enum object, so given an enum like

public enum Day {
         


        

Answer 1

and it would implement exactly the functionality of the Day.lookup() method for any enum, without the need to re-write the same method for each enum.

Probably you can write a utility class for doing that as the following.

public class EnumUtil {

    private EnumUtil(){
        //A utility class
    }

    public static > T lookup(Class enumType,
                                                   String name) {
        for (T enumn : enumType.getEnumConstants()) {
            if (enumn.name().equalsIgnoreCase(name)) {
                return enumn;
            }
        }
        return null;
    }

    // Just for testing
    public static void main(String[] args) {
        System.out.println(EnumUtil.lookup(Day.class, "friday"));
        System.out.println(EnumUtil.lookup(Day.class, "FrIdAy"));
    }

}

enum Day {
    Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday
}

It would have been nice if there was a way in Java for us to extend the Enum class by implicitly adding methods just the way values() method is added but I don't think there is a way to do that.