How to correctly find the stream characteristics in Java-8?

Question

While doing stream operations, during the intermediate/pipeline operations the streams would be created with different characteristics(e.g: SORTED/SIZED/DISTINCT/ORDERED) - Mastering Lambdas(Ch 6)

Stream.of(8,3,5,6,7,4) // ORDERED, SIZED
.filter(i->i%2==0) // ORDERED
.sorted() // ORDERED, SORTED
.distinct() // DISTINCT, ORDERED, SORTED
.map(i->i+1) // ORDERED
.unordered(); // none

How do we find out the different characteristics of the stream as mentioned in the above snippet?

Answer 1

At each stage you can call:

int c = stream.spliterator().characteristics();

And then test the result against the constants defined in the Spliterator class. For example to see if the stream is ordered:

boolean isOrdered = (c & Spliterator.ORDERED) == Spliterator.ORDERED;

Alternatively you can use:

boolean isOrdered = stream.spliterator().hasCharacteristics(Spliterator.ORDERED);