Java enums: Gathering info from another enums
- by Samuel Carrijo
I made a similar question a few days ago, but now I have new requirements, and new challenges =). As usual, I'm using the animal enums for didactic purposes, once I don't want to explain domain-specific stuff
I have a basic enum of animals, which is used by the whole zoo (I can add stuff to it, but must keep compatibility):
public enum Animal {
DOG,
ELEPHANT,
WHALE,
SHRIMP,
BIRD,
GIRAFFE;
}
I need to categorize them in a few, non-related categories, like gray animals (whale (my whale is gray) and elephant), small animals (bird, shrimp and dog), sea animals (whale and shrimp).
I could, as suggested in my previous questions, add a lot of booleans, like isGray, isSmall and isFromSea, but I'd like an approach where I could keep this somewhere else (so my enum doesn't need to know much). Something like:
public enum Animal {
DOG,
ELEPHANT,
WHALE,
SHRIMP,
BIRD,
GIRAFFE;
public boolean isGray() {
// What comes here?
}
}
Somewhere else
public enum GrayAnimal {
WHALE,
ELEPHANT;
}
How is this possible? Am I requesting too much from Java?
