http://zeroturnaround.com/rebellabs/watch-out-for-these-10-common-pitfalls-of-experienced-java-developers-architects/ point #9

AnimalType.java

public enum AnimalType {

  DOG {
    public Animal createAnimal() {
      return new Dog();
    }
  },
  CAT {
    public Animal createAnimal() {
      return new Cat();
    }
  },
  COW {
    public Animal createAnimal() {
      return new Cow();
    }
  },
  ANY {
    public Animal createAnimal() {
      return new Cat();
    }
  };

  public abstract Animal createAnimal();

}