From ffffa055f0a3b9b529567c28c1a5c8b33c5d719e Mon Sep 17 00:00:00 2001
From: dugenkui03 <dugk@foxmail.com>
Date: Thu, 17 Mar 2022 23:25:56 +0800
Subject: [PATCH] Return UnmodifiableMap in MVC
 PathVariableMapMethodArgumentResolver

See gh-28127
Closes gh-28352
---
 .../annotation/PathVariableMapMethodArgumentResolver.java    | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/PathVariableMapMethodArgumentResolver.java b/spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/PathVariableMapMethodArgumentResolver.java
index eb5b4b0884..bbfd5a54d3 100644
--- a/spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/PathVariableMapMethodArgumentResolver.java
+++ b/spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/PathVariableMapMethodArgumentResolver.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,7 +17,6 @@
 package org.springframework.web.servlet.mvc.method.annotation;
 
 import java.util.Collections;
-import java.util.LinkedHashMap;
 import java.util.Map;
 
 import org.springframework.core.MethodParameter;
@@ -63,7 +62,7 @@ public class PathVariableMapMethodArgumentResolver implements HandlerMethodArgum
 						HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE, RequestAttributes.SCOPE_REQUEST);
 
 		if (!CollectionUtils.isEmpty(uriTemplateVars)) {
-			return new LinkedHashMap<>(uriTemplateVars);
+			return Collections.unmodifiableMap(uriTemplateVars);
 		}
 		else {
 			return Collections.emptyMap();