diff options
Diffstat (limited to 'vid-automation/src/test/java/org/onap/vid/api/Streams.java')
-rw-r--r-- | vid-automation/src/test/java/org/onap/vid/api/Streams.java | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/vid-automation/src/test/java/org/onap/vid/api/Streams.java b/vid-automation/src/test/java/org/onap/vid/api/Streams.java new file mode 100644 index 000000000..b53187e09 --- /dev/null +++ b/vid-automation/src/test/java/org/onap/vid/api/Streams.java @@ -0,0 +1,47 @@ +package org.onap.vid.api; + +import java.util.Iterator; +import java.util.Spliterator; +import java.util.Spliterators; +import java.util.function.Consumer; +import java.util.function.Predicate; +import java.util.stream.Stream; +import java.util.stream.StreamSupport; + +public class Streams { + public static <R> Predicate<R> not(Predicate<R> predicate) { + return predicate.negate(); + } + + public static <T> Stream<T> fromIterator(final Iterator<T> iterator) { + Iterable<T> iterable = () -> iterator; + return StreamSupport.<T>stream(iterable.spliterator(), false); + } + + + // https://stackoverflow.com/questions/20746429/limit-a-stream-by-a-predicate + private static <T> Spliterator<T> takeWhile( + Spliterator<T> splitr, Predicate<? super T> predicate) { + return new Spliterators.AbstractSpliterator<T>(splitr.estimateSize(), 0) { + boolean stillGoing = true; + @Override public boolean tryAdvance(Consumer<? super T> consumer) { + if (stillGoing) { + boolean hadNext = splitr.tryAdvance(elem -> { + if (predicate.test(elem)) { + consumer.accept(elem); + } else { + stillGoing = false; + } + }); + return hadNext && stillGoing; + } + return false; + } + }; + } + + public static <T> Stream<T> takeWhile(Stream<T> stream, Predicate<? super T> predicate) { + return StreamSupport.stream(takeWhile(stream.spliterator(), predicate), false); + } + +} |