Fix for encoding issue with MvcUriComponentsBuilder

Provide method for stronger encoding of expanded URI variables when
building links from views.

Issue: SPR-17027

Author: rstoyanchev

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/MvcUriComponentsBuilder.java

@@ -832,6 +832,16 @@ public MethodArgumentBuilder arg(int index, Object value) {
 			return this;
 		}
 
+		/**
+		 * Use this method only if you need to apply strong encoding to expanded
+		 * URI variables by quoting all characters with reserved meaning.
+		 * @since 5.0.8
+		 */
+		public MethodArgumentBuilder encode() {
+			this.baseUrl.encode();
+			return this;
+		}
+
 		public String build() {
 			return fromMethodInternal(this.baseUrl, this.controllerType, this.method, this.argumentValues)
 					.build(false).encode().toUriString();

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/MvcUriComponentsBuilderTests.java

@@ -363,12 +363,7 @@ public void fromMethodNameWithStringReturnType() {
 
 	@Test
 	public void fromMappingNamePlain() {
-		AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
-		context.setServletContext(new MockServletContext());
-		context.register(WebConfig.class);
-		context.refresh();
-
-		this.request.setAttribute(DispatcherServlet.WEB_APPLICATION_CONTEXT_ATTRIBUTE, context);
+		initWebApplicationContext(WebConfig.class);
 		this.request.setServerName("example.org");
 		this.request.setServerPort(9999);
 		this.request.setContextPath("/base");
@@ -380,18 +375,35 @@ public void fromMappingNamePlain() {
 
 	@Test
 	public void fromMappingNameWithCustomBaseUrl() {
-		AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
-		context.setServletContext(new MockServletContext());
-		context.register(WebConfig.class);
-		context.refresh();
-
-		this.request.setAttribute(DispatcherServlet.WEB_APPLICATION_CONTEXT_ATTRIBUTE, context);
+		initWebApplicationContext(WebConfig.class);
 
 		UriComponentsBuilder baseUrl = UriComponentsBuilder.fromUriString("http://example.org:9999/base");
 		MvcUriComponentsBuilder mvcBuilder = relativeTo(baseUrl);
 		String url = mvcBuilder.withMappingName("PAC#getAddressesForCountry").arg(0, "DE").buildAndExpand(123);
 		assertEquals("http://example.org:9999/base/people/123/addresses/DE", url);
 	}
+   
+	@Test // SPR-17027
+	public void fromMappingNameWithEncoding() {
+		initWebApplicationContext(WebConfig.class);
+
+		this.request.setServerName("example.org");
+		this.request.setServerPort(9999);
+		this.request.setContextPath("/base");
+
+		String mappingName = "PAC#getAddressesForCountry";
+		String url = fromMappingName(mappingName).arg(0, "DE;FR").encode().buildAndExpand("_+_");
+		assertEquals("/base/people/_%2B_/addresses/DE%3BFR", url);
+	}
+
+	private void initWebApplicationContext(Class<?> configClass) {
+		AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
+		context.setServletContext(new MockServletContext());
+		context.register(configClass);
+		context.refresh();
+
+		this.request.setAttribute(DispatcherServlet.WEB_APPLICATION_CONTEXT_ATTRIBUTE, context);
+	}
 
 
 	static class Person {