Java HashSet with a custom equality criteria? [duplicate]

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Nope, you’ve found exactly the solution you’re supposed to use.

Even for TreeSet, it’s frowned upon to use comparison criteria that aren’t compatible with equals:

Note that the ordering maintained by a sorted set (whether or not an explicit comparator is provided) must be consistent with equals if the sorted set is to correctly implement the Set interface.

I don’t know about Apache Commons, but Guava specifically rejected requests for this sort of thing, although you can achieve what you want using Guava Equivalence:

Equivalence<T> equivalence = new Equivalence<T>() {
    @Override
    protected boolean doEquivalent(T a, T b) {
        return CustomComparator.equals(a, b);
    }

    @Override
    protected int doHash(T item) {
        return CustomHashCodeGenerator.hashCode(item);
    }
};
List<T> items = getItems();
Set<Equivalence.Wrapper<T>> setWithWrappedObjects = items.stream()
    .map(item -> equivalence.wrap(item))
    .collect(Collectors.toSet());

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