I suggest changing the constructors visibility from public to private - or better remove it.

It is not tested, and there is no need to implement it.

The required methods are not even consistent to the IntStream interface (e.g IntStream.of takes int varargs, not an int[], and the existence of methods that simply doesn't exist in the interface), so it's completely wrong to claim that we're using the Stream API, or implementing an IntStream. What is being done is more like implementing an IntStream-like class with a custom API.