There are 2 repositories under primitive-collections topic.
Eclipse Collections is a collections framework for Java with optimized data structures and a rich, functional and fluent API.
A Primitive Collection library that reduces memory usage and improves performance
Java library providing primitive collections.
Library built under the fastutil which offers various methods for creating collections, which makes your code more efficient and faster
Java primitive collections for char, int, float, long, and double Lists, SortedLists, ArrayViews, Iterators, and Maps.