From ee320387db793fddbf18b6d91f253e90c5c811e8 Mon Sep 17 00:00:00 2001
From: javalover123 <javalover123@foxmail.com>
Date: Wed, 21 Jun 2023 22:53:09 +0800
Subject: [PATCH] =?UTF-8?q?fix=EF=BC=9Alist=20=E4=B8=BA=E7=A9=BA=E6=97=B6?=
 =?UTF-8?q?=EF=BC=8CCollUtil.max=20=E6=8A=9B=E5=BC=82=E5=B8=B8=20#I7FCA3?=
 =?UTF-8?q?=20https://gitee.com/dromara/hutool/issues/I7FCA3?=
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---
 .../cn/hutool/core/collection/CollUtil.java    |  4 ++--
 .../hutool/core/collection/CollUtilTest.java   | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java b/hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java
index 9d52ab3c3..a597a063c 100755
--- a/hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java
@@ -2884,7 +2884,7 @@ public class CollUtil {
 	 * @since 4.6.5
 	 */
 	public static <T extends Comparable<? super T>> T max(Collection<T> coll) {
-		return Collections.max(coll);
+		return isEmpty(coll) ? null : Collections.max(coll);
 	}
 
 	/**
@@ -2897,7 +2897,7 @@ public class CollUtil {
 	 * @since 4.6.5
 	 */
 	public static <T extends Comparable<? super T>> T min(Collection<T> coll) {
-		return Collections.min(coll);
+		return isEmpty(coll) ? null : Collections.min(coll);
 	}
 
 	/**
diff --git a/hutool-core/src/test/java/cn/hutool/core/collection/CollUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/collection/CollUtilTest.java
index ac869e273..585c1cd6d 100755
--- a/hutool-core/src/test/java/cn/hutool/core/collection/CollUtilTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/collection/CollUtilTest.java
@@ -1066,4 +1066,22 @@ public class CollUtilTest {
 		Assert.assertFalse(CollUtil.allMatch(list, i -> i == 1));
 		Assert.assertTrue(CollUtil.allMatch(list, i -> i <= 6));
 	}
+
+	@Test
+	public void maxTest() {
+		List<Integer> list = Arrays.asList(1, 2, 3, 4, 5, 6);
+		Assert.assertEquals((Integer) 6, CollUtil.max(list));
+	}
+
+	@Test
+	public void maxEmptyTest() {
+		final List<? extends Comparable> emptyList = Collections.emptyList();
+		Assert.assertNull(CollUtil.max(emptyList));
+	}
+
+	@Test
+	public void minNullTest() {
+		Assert.assertNull(CollUtil.max(null));
+	}
+
 }