Java streams findAny() encounters null pointer exception after filter() operation filters out everything

Question

I am having trouble figuring why findAny() throws a null pointer exception after filter() operation on a stream. In this particular test case, the filt

Answer 1

No, it's not the behavior, when the stream doesn't contain any elements. In which case it instead returns an Optional.empty().

Also, the NPE is the cause of a null value in the stream, as stated in the javadocs:

Returns:
an Optional describing some element of this stream, or an empty Optional if the stream is empty

Throws:
NullPointerException - if the element selected is null