Zipping streams using JDK8 with lambda (java.util.stream.Streams.zip)

Question

In JDK 8 with lambda b93 there was a class java.util.stream.Streams.zip in b93 which could be used to zip streams (this is illustrated in the tutorial Exploring Java8 Lambda

Answer 1

Zipping two streams using JDK8 with lambda (gist).

public static  Stream zip(Stream streamA, Stream streamB, BiFunction zipper) {
    final Iterator iteratorA = streamA.iterator();
    final Iterator iteratorB = streamB.iterator();
    final Iterator iteratorC = new Iterator() {
        @Override
        public boolean hasNext() {
            return iteratorA.hasNext() && iteratorB.hasNext();
        }

        @Override
        public C next() {
            return zipper.apply(iteratorA.next(), iteratorB.next());
        }
    };
    final boolean parallel = streamA.isParallel() || streamB.isParallel();
    return iteratorToFiniteStream(iteratorC, parallel);
}

public static  Stream iteratorToFiniteStream(Iterator iterator, boolean parallel) {
    final Iterable iterable = () -> iterator;
    return StreamSupport.stream(iterable.spliterator(), parallel);
}