Java : Best way to declare a static list constant

public class MyListConstant {

      public static final List CONSTANT = Collections.unmodifiableList(getConstant());

      private static List getConstant() {

            List constant1 = new ArrayList();

            constant1.add("a");

            constant1.add("b");

            constant1.add("c");

            constant1.add("d");

            return constant1;

      }

}

Note:

1. It is better to use Array constants instead of list constants.
2. List constant need to be created with unmodifiableList method otherwise it will modified with its set method.

CONSTANT.set(1, "replaced");