Is it OK to use == on enums in Java?

Question

Is it OK to use == on enums in Java, or do I need to use .equals()? In my testing, == always works, but I\'m not sure if I\'m guarant

Answer 1

Note that there is problem when transfering enum via RMI/IIOP. See this thread:

http://www.velocityreviews.com/forums/t390342-enum-equality.html

Answer 2

Enums are a great place to jam polymorphic code.

enum Rounding {
  ROUND_UP {
    public int round(double n) { ...; }
  },
  ROUND_DOWN {
    public int round(double n) { ...; }
  };

  public abstract int round(double n);
}

int foo(Rounding roundMethod) {
  return roundMethod.round(someCalculation());
}

int bar() {
  return foo(Rounding.ROUND_UP);
}