org.onap migration

Change-Id: I52f0b2851f2c765752b6d21f49b32136d7d72a3d
Issue-ID: VID-86
Signed-off-by: Ofir Sonsino <os0695@att.com>

1 files changed, 47 insertions, 0 deletions

diff --git a/vid-app-common/src/main/java/org/onap/vid/utils/Streams.java b/vid-app-common/src/main/java/org/onap/vid/utils/Streams.java
new file mode 100644
index 000000000..7f81b225a
--- /dev/null
+++ b/vid-app-common/src/main/java/org/onap/vid/utils/Streams.java
@@ -0,0 +1,47 @@
+package org.onap.vid.utils;
+
+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);
+    }
+
+}