From a6151b6ee81c6406a6a4bc4d21b2f49c109bcabf Mon Sep 17 00:00:00 2001
From: Will <5499819+guizhonglin@user.noreply.gitee.com>
Date: Tue, 25 Nov 2025 18:08:03 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E5=A4=8DStrUtil.str(ByteBuffer,=20Cha?=
 =?UTF-8?q?rset)=20=E6=96=B9=E6=B3=95=E4=BF=AE=E6=94=B9=E5=85=A5=E5=8F=82?=
 =?UTF-8?q?=20ByteBuffer=20=E7=9A=84=20position=EF=BC=8C=E5=AF=BC=E8=87=B4?=
 =?UTF-8?q?=E5=85=A5=E5=8F=82=E5=8F=98=E5=8C=96?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../main/java/cn/hutool/core/util/StrUtil.java |  2 +-
 .../java/cn/hutool/core/io/BufferUtilTest.java | 18 ++++++++++++++++++
 2 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/hutool-core/src/main/java/cn/hutool/core/util/StrUtil.java b/hutool-core/src/main/java/cn/hutool/core/util/StrUtil.java
index f37eb27e8..deecb0665 100755
--- a/hutool-core/src/main/java/cn/hutool/core/util/StrUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/util/StrUtil.java
@@ -261,7 +261,7 @@ public class StrUtil extends CharSequenceUtil implements StrPool {
 		if (null == charset) {
 			charset = Charset.defaultCharset();
 		}
-		return charset.decode(data).toString();
+		return charset.decode(data.duplicate()).toString();
 	}
 
 	/**
diff --git a/hutool-core/src/test/java/cn/hutool/core/io/BufferUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/io/BufferUtilTest.java
index bc2755eea..c53dcd7ff 100644
--- a/hutool-core/src/test/java/cn/hutool/core/io/BufferUtilTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/io/BufferUtilTest.java
@@ -1,6 +1,7 @@
 package cn.hutool.core.io;
 
 import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
 
 import static org.junit.jupiter.api.Assertions.*;
 import org.junit.jupiter.api.Test;
@@ -63,4 +64,21 @@ public class BufferUtilTest {
 		// 读取剩余部分
 		assertEquals("cc", StrUtil.utf8Str(BufferUtil.readBytes(buffer)));
 	}
+
+	@Test
+	public void testByteBufferSideEffect() {
+		String originalText = "Hello";
+		ByteBuffer buffer = ByteBuffer.wrap(originalText.getBytes(StandardCharsets.UTF_8));
+		// 此时 buffer.remaining() == 5
+		assertEquals(5, buffer.remaining());
+
+		// 调用工具类转换，打印buffer内容
+		String result = StrUtil.str(buffer, StandardCharsets.UTF_8);
+		assertEquals(originalText, result);
+
+		// 预期：
+		// 工具类不应该修改原 buffer 的指针，remaining 应该依然为 5
+		// 再次调用工具类转换，输出结果应该不变
+		assertEquals(originalText, StrUtil.str(buffer, StandardCharsets.UTF_8));
+	}
 }