From bf890d17f16ea0696468e55f2c9b9a22d8f0e070 Mon Sep 17 00:00:00 2001
From: Looly <loolly@aliyun.com>
Date: Mon, 18 Mar 2024 09:53:15 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E5=A4=8DClassUtil.getTypeArgument()?=
 =?UTF-8?q?=20=E8=8E=B7=E5=8F=96=E6=B3=9B=E5=9E=8B=E5=AD=98=E5=9C=A8null?=
 =?UTF-8?q?=E9=97=AE=E9=A2=98?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
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---
 CHANGELOG.md                                  |  3 +-
 .../java/cn/hutool/core/util/TypeUtil.java    |  7 ++--
 .../cn/hutool/core/util/Issue3516Test.java    | 36 +++++++++++++++++++
 3 files changed, 42 insertions(+), 4 deletions(-)
 create mode 100644 hutool-core/src/test/java/cn/hutool/core/util/Issue3516Test.java

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 95d7f3255..3556c4f7f 100755
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,7 +2,7 @@
 # 🚀Changelog
 
 -------------------------------------------------------------------------------------------------------------
-# 5.8.27(2024-03-15)
+# 5.8.27(2024-03-18)
 
 ### 🐣新特性
 * 【extra 】      FreemarkerEngine修改默认版本参数
@@ -17,6 +17,7 @@
 * 【http  】      修复CVE-2022-22885，HttpGlobalConfig可选关闭信任host（issue#2042@Github）
 * 【core  】      修复DateUtil.betweenYear闰年2月问题（issue#I97U3J@Gitee）
 * 【captcha】     修复Graphics2D的资源没释放问题（issue#I98PYN@Gitee）
+* 【core  】      修复ClassUtil.getTypeArgument() 获取泛型存在null问题（issue#3516@Github）
 
 -------------------------------------------------------------------------------------------------------------
 # 5.8.26(2024-02-10)
diff --git a/hutool-core/src/main/java/cn/hutool/core/util/TypeUtil.java b/hutool-core/src/main/java/cn/hutool/core/util/TypeUtil.java
index 70d92ca41..738c68171 100755
--- a/hutool-core/src/main/java/cn/hutool/core/util/TypeUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/util/TypeUtil.java
@@ -1,5 +1,6 @@
 package cn.hutool.core.util;
 
+import cn.hutool.core.lang.Console;
 import cn.hutool.core.lang.ParameterizedTypeImpl;
 import cn.hutool.core.lang.reflect.ActualTypeMapperPool;
 
@@ -309,7 +310,6 @@ public class TypeUtil {
 	 *
 	 * @param clazz 类
 	 * @return 泛型父类或接口数组
-	 * @since 6.0.0
 	 */
 	public static ParameterizedType[] getGenerics(final Class<?> clazz) {
 		final List<ParameterizedType> result = new ArrayList<>();
@@ -326,8 +326,9 @@ public class TypeUtil {
 		final Type[] genericInterfaces = clazz.getGenericInterfaces();
 		if (ArrayUtil.isNotEmpty(genericInterfaces)) {
 			for (final Type genericInterface : genericInterfaces) {
-				if (genericInterface instanceof ParameterizedType) {
-					result.add((ParameterizedType) genericInterface);
+				final ParameterizedType parameterizedType = toParameterizedType(genericInterface);
+				if(null != parameterizedType){
+					result.add(parameterizedType);
 				}
 			}
 		}
diff --git a/hutool-core/src/test/java/cn/hutool/core/util/Issue3516Test.java b/hutool-core/src/test/java/cn/hutool/core/util/Issue3516Test.java
new file mode 100644
index 000000000..58bc70eb2
--- /dev/null
+++ b/hutool-core/src/test/java/cn/hutool/core/util/Issue3516Test.java
@@ -0,0 +1,36 @@
+package cn.hutool.core.util;
+
+import cn.hutool.core.lang.Console;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.lang.reflect.Type;
+import java.util.function.Function;
+
+public class Issue3516Test {
+
+	@Test
+	public void getTypeArgumentTest() {
+		final Type typeArgument = TypeUtil.getTypeArgument(Demo.class, 0);
+		Assert.assertEquals(B.class, typeArgument);
+	}
+
+	static class Demo implements A2B{
+		@Override
+		public A apply(B arg0) {
+			final A a = new A();
+			return a;
+		}
+	}
+
+	static class A {
+		private String name;
+	}
+
+	static class B {
+		private String name;
+	}
+
+	interface A2B extends Function<B, A> {
+	}
+}