Here you can find the source of zip(List
| Parameter | Description |
|---|---|
| streams | List of all streams we want to zip |
| T | Type of items contained in the List |
public static <T> Stream<List<T>> zip(List<Stream<T>> streams)
//package com.java2s;
//License from project: Open Source License
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
public class Main {
/**/* w w w . ja va2s . c o m*/
* Convert a List of Stream into a Stream of List by associating each
* element of one list with the element at the same position in the latters.
* All streams in the lists should have the same length.
*
* @param streams
* List of all streams we want to zip
* @param <T>
* Type of items contained in the List
* @return Stream of list
*/
public static <T> Stream<List<T>> zip(List<Stream<T>> streams) {
final List<Iterator<T>> iteratorsList = streams.stream()
.map(Stream::iterator).collect(Collectors.toList());
final Iterator<List<T>> zippedIterator = new Iterator<List<T>>() {
@Override
public boolean hasNext() {
for (Iterator<T> it : iteratorsList)
if (it.hasNext())
return true;
return false;
}
@Override
public List<T> next() {
List<T> next = new ArrayList<>();
for (Iterator<T> it : iteratorsList)
next.add(it.next());
return next;
}
};
final boolean isParallel = true;
return StreamSupport.stream(Spliterators.spliteratorUnknownSize(
zippedIterator, Spliterator.SORTED | Spliterator.DISTINCT),
isParallel);
}
}