Java Data Type - 如何在静态枚举中获取下一个

enum Planet {
  EARTH, MARS;
  Planet() {
  }

  public Planet getNext() {
    return values()[(ordinal() + 1) % values().length];
  }
}

public class Main {
  static Planet current = Planet.EARTH;
  public static void main(String[] args) {
    setNext();
  }
  public static void setNext() {
    current = current.getNext();
  }

  public static Planet getCurrent() {
    return current;
  }
}