From 6045f86da1a16597473ac0cf7acd82282e4cb60e Mon Sep 17 00:00:00 2001
From: John Blum <jblum@pivotal.io>
Date: Wed, 8 Apr 2020 14:00:37 -0700
Subject: [PATCH] DATAGEODE-302 - Add 'nullSafeIsEmpty(:Stream) utility method
 to StreamUtils.

---
 .../data/gemfire/util/StreamUtils.java        | 12 +++++++++++
 .../gemfire/util/StreamUtilsUnitTests.java    | 20 +++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/spring-data-geode/src/main/java/org/springframework/data/gemfire/util/StreamUtils.java b/spring-data-geode/src/main/java/org/springframework/data/gemfire/util/StreamUtils.java
index b87dca0c..f4f37bbf 100644
--- a/spring-data-geode/src/main/java/org/springframework/data/gemfire/util/StreamUtils.java
+++ b/spring-data-geode/src/main/java/org/springframework/data/gemfire/util/StreamUtils.java
@@ -61,6 +61,18 @@ public abstract class StreamUtils {
 		return nullSafeStream(stream).count();
 	}
 
+	/**
+	 * Null-safe utility method used to determine whether the given {@link Stream} is empty.
+	 *
+	 * @param stream {@link Stream} to evalute.
+	 * @return a boolean value indicating whether the given {@link Stream} is empty.
+	 * @see java.util.stream.Stream
+	 * @see #nullSafeCount(Stream)
+	 */
+	public static boolean nullSafeIsEmpty(Stream<?> stream) {
+		return nullSafeCount(stream) == 0L;
+	}
+
 	/**
 	 * Utility method used to guard against {@literal null} {@link Stream Streams}.
 	 *
diff --git a/spring-data-geode/src/test/java/org/springframework/data/gemfire/util/StreamUtilsUnitTests.java b/spring-data-geode/src/test/java/org/springframework/data/gemfire/util/StreamUtilsUnitTests.java
index fb3e863c..710de55d 100644
--- a/spring-data-geode/src/test/java/org/springframework/data/gemfire/util/StreamUtilsUnitTests.java
+++ b/spring-data-geode/src/test/java/org/springframework/data/gemfire/util/StreamUtilsUnitTests.java
@@ -106,6 +106,26 @@ public class StreamUtilsUnitTests {
 		assertThat(StreamUtils.nullSafeCount(Stream.of(1, 2))).isEqualTo(2);
 	}
 
+	@Test
+	public void isEmptyWithNullStream() {
+		assertThat(StreamUtils.nullSafeIsEmpty(null)).isTrue();
+	}
+
+	@Test
+	public void isEmptyWithEmptyStream() {
+		assertThat(StreamUtils.nullSafeIsEmpty(Stream.empty())).isTrue();
+	}
+
+	@Test
+	public void isEmptyWithOneElementStream() {
+		assertThat(StreamUtils.nullSafeIsEmpty(Stream.of(1))).isFalse();
+	}
+
+	@Test
+	public void isEmptyWithTwoElementStream() {
+		assertThat(StreamUtils.nullSafeIsEmpty(Stream.of(1, 2))).isFalse();
+	}
+
 	@Test
 	public void nullSafeStreamWithStream() {