What is the best way to compare enum and non-enum objects in Java?

Question

Having the following definitions

public interface AnInt {
    int value();
}

public enum FirstTwo implements AnInt {
    ONE(() -> 1),
    TWO(() -> 2);
}

Is there a way to correctly implement comparison to use standard equals:

class AnotherOne implements AnInt {
    @Override
    int value() {
        return 1;
    }
}
ONE.equals(new AnotherOne()); // -> true

Answer 1

Given the equals() of java.lang.Enum (the parent of all enum classes) is final, you can't do this.

And in general, considering objects of different classes, especially if there is no parent-child relation between those classes, equal is an accident waiting to happen (unless carefully designed). I recommend solving this in a different way (eg a custom comparison method, or wrapper classes that provide a facade for the equality check, a Comparator<AnInt> implementation as companion to the AnInt interface, etc).