Fix improper encoding of '+' in query parameter values when rewrite query parameter

Signed-off-by: raccoonback <kosb15@naver.com>

Author: raccoonback

spring-cloud-gateway-server-mvc/src/main/java/org/springframework/cloud/gateway/server/mvc/filter/BeforeFilterFunctions.java

@@ -351,7 +351,7 @@ public static Function<ServerRequest, ServerRequest> rewriteRequestParameter(Str
 				queryParams.add(name, replacement);
 			}
 
-			MultiValueMap<String, String> encodedQueryParams = UriUtils.encodeQueryParams(queryParams);
+			MultiValueMap<String, String> encodedQueryParams = MvcUtils.encodeQueryParams(queryParams);
 			URI rewrittenUri = UriComponentsBuilder.fromUri(request.uri())
 				.replaceQueryParams(unmodifiableMultiValueMap(encodedQueryParams))
 				.build(true)

spring-cloud-gateway-server-mvc/src/test/java/org/springframework/cloud/gateway/server/mvc/filter/BeforeFilterFunctionsTests.java

@@ -129,19 +129,36 @@ void rewriteEncodedRequestParameter() {
 		assertThat(result.uri().toString()).hasToString("http://localhost/path?baz=qux&foo%5B%5D=replacement%5B%5D");
 	}
 
+	@Test
+	void rewritePlusSignRequestParameter() {
+		MockHttpServletRequest servletRequest = MockMvcRequestBuilders.get("http://localhost/path")
+			.param("foo", "bar")
+			.param("baz", "qux")
+			.buildRequest(null);
+
+		ServerRequest request = ServerRequest.create(servletRequest, Collections.emptyList());
+
+		ServerRequest result = BeforeFilterFunctions.rewriteRequestParameter("foo", "replacement+").apply(request);
+
+		assertThat(result.param("foo")).isPresent().hasValue("replacement+");
+		assertThat(result.uri().toString()).hasToString("http://localhost/path?baz=qux&foo=replacement%2B");
+	}
+
 	@Test
 	void rewriteRequestParameterWithEncodedRemainParameters() {
 		MockHttpServletRequest servletRequest = MockMvcRequestBuilders.get("http://localhost/path")
 			.param("foo", "bar")
 			.param("baz[]", "qux[]")
+			.param("quux", "corge+")
 			.buildRequest(null);
 
 		ServerRequest request = ServerRequest.create(servletRequest, Collections.emptyList());
 
 		ServerRequest result = BeforeFilterFunctions.rewriteRequestParameter("foo", "replacement").apply(request);
 
 		assertThat(result.param("foo")).isPresent().hasValue("replacement");
-		assertThat(result.uri().toString()).hasToString("http://localhost/path?baz%5B%5D=qux%5B%5D&foo=replacement");
+		assertThat(result.uri().toString())
+			.hasToString("http://localhost/path?baz%5B%5D=qux%5B%5D&quux=corge%2B&foo=replacement");
 	}
 
 	@Test