EnumMap<Object,Set<x>> - how to have unique values for every key

Question

I'm trying to make something like this.

Let's say my EnumMap looks like this EnumMap<Animals, Set<Integer>>. I have keys like: Dog,Fish,Cat from Animals class. And I want to print all values from Animals Dog, Fish and Cat.

• Dog has values: - 1,2,3
• Fish has values - 4,5,6
• Cat has values: - 2,5,7

As you can see, Cat has 2 from Dog, and 5 from Fish. So the output will be: 1,2,3,4,5,6,2,5,7.

I want to remove duplicates during adding process to EnumMap.

So it should be like: 1,2,3,4,5,6,7. I cannot filter later after adding all values. How can I do this?

Answer 1

This should help:

public class Test {

    private Map<Animal, Set<Integer>> m = new EnumMap<>(Animal.class);

    public Test() {
        m.put(Animal.DOG, Set.of(1, 2, 3));
        m.put(Animal.FISH, Set.of(4, 5, 6));
    }

    public static void main(String[] args) {
        Test t = new Test();
        t.addValueIfNotPresent(Animal.CAT, 2);
        t.addValueIfNotPresent(Animal.CAT, 5);
        t.addValueIfNotPresent(Animal.CAT, 7);

        System.out.println(t.m);
    }

    private void addValueIfNotPresent(Animal key, Integer value) {
        if (m.values().stream().flatMap(Collection::stream).noneMatch(value::equals)) {
            m.compute(key, (animal, integers) -> {
                if (Objects.isNull(integers)) {
                    Set<Integer> s = new HashSet<>();
                    s.add(value);
                    return s;
                } else {
                    integers.add(value);
                    return integers;
                }
            });
        }
    }

    enum Animal {DOG, CAT, FISH}
}

Output:

{DOG=[3, 2, 1], CAT=[7], FISH=[4, 6, 5]}

This is not very optimized and clean, but should give you an idea on how to proceed.