SPR-8020 Support UriComponentsBuilder as a controller method argument.

The UriComponentsBuilder instance passed into the method is initialized
with current request information including host, scheme, port, context
path, and the servlet mapping's literal part.

Also added shortcut methods to buildAndExpand in UriComponentsBuilder.

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter.java

@@ -89,6 +89,7 @@ import org.springframework.web.servlet.mvc.method.annotation.support.ServletCook
 import org.springframework.web.servlet.mvc.method.annotation.support.ServletModelAttributeMethodProcessor;
 import org.springframework.web.servlet.mvc.method.annotation.support.ServletRequestMethodArgumentResolver;
 import org.springframework.web.servlet.mvc.method.annotation.support.ServletResponseMethodArgumentResolver;
+import org.springframework.web.servlet.mvc.method.annotation.support.UriComponentsBuilderMethodArgumentResolver;
 import org.springframework.web.servlet.mvc.method.annotation.support.ViewMethodReturnValueHandler;
 import org.springframework.web.servlet.mvc.method.annotation.support.ViewNameMethodReturnValueHandler;
 import org.springframework.web.servlet.mvc.support.RedirectAttributes;
@@ -425,7 +426,7 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter i
 	 * Return the list of argument resolvers to use including built-in resolvers
 	 * and custom resolvers provided via {@link #setCustomArgumentResolvers}.
 	 */
-	protected List<HandlerMethodArgumentResolver> getDefaultArgumentResolvers() {
+	private List<HandlerMethodArgumentResolver> getDefaultArgumentResolvers() {
 		List<HandlerMethodArgumentResolver> resolvers = new ArrayList<HandlerMethodArgumentResolver>();
 
 		// Annotation-based argument resolution
@@ -449,6 +450,7 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter i
 		resolvers.add(new MapMethodProcessor());
 		resolvers.add(new ErrorsMethodArgumentResolver());
 		resolvers.add(new SessionStatusMethodArgumentResolver());
+		resolvers.add(new UriComponentsBuilderMethodArgumentResolver());
 
 		// Custom arguments
 		if (getCustomArgumentResolvers() != null) {
@@ -466,7 +468,7 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter i
 	 * Return the list of argument resolvers to use for {@code @InitBinder} 
 	 * methods including built-in and custom resolvers.
 	 */
-	protected List<HandlerMethodArgumentResolver> getDefaultInitBinderArgumentResolvers() {
+	private List<HandlerMethodArgumentResolver> getDefaultInitBinderArgumentResolvers() {
 		List<HandlerMethodArgumentResolver> resolvers = new ArrayList<HandlerMethodArgumentResolver>();
 
 		// Annotation-based argument resolution
@@ -494,7 +496,7 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter i
 	 * Return the list of return value handlers to use including built-in and 
 	 * custom handlers provided via {@link #setReturnValueHandlers}.
 	 */
-	protected List<HandlerMethodReturnValueHandler> getDefaultReturnValueHandlers() {
+	private List<HandlerMethodReturnValueHandler> getDefaultReturnValueHandlers() {
 		List<HandlerMethodReturnValueHandler> handlers = new ArrayList<HandlerMethodReturnValueHandler>();
 
 		// Single-purpose return value types

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/UriComponentsBuilderMethodArgumentResolver.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2002-2011 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.web.servlet.mvc.method.annotation.support;
+
+import javax.servlet.http.HttpServletRequest;
+
+import org.springframework.core.MethodParameter;
+import org.springframework.web.bind.support.WebDataBinderFactory;
+import org.springframework.web.context.request.NativeWebRequest;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
+import org.springframework.web.method.support.ModelAndViewContainer;
+import org.springframework.web.servlet.support.ServletUriComponentsBuilder;
+import org.springframework.web.util.UriComponentsBuilder;
+
+/**
+ * Resolvers argument values of type {@link UriComponentsBuilder}.
+ * 
+ * <p>The returned instance is initialized via
+ * {@link ServletUriComponentsBuilder#fromServletMapping(HttpServletRequest)}.
+ *
+ * @author Rossen Stoyanchev
+ * @since 3.1
+ */
+public class UriComponentsBuilderMethodArgumentResolver implements HandlerMethodArgumentResolver {
+
+	public boolean supportsParameter(MethodParameter parameter) {
+		return UriComponentsBuilder.class.isAssignableFrom(parameter.getParameterType());
+	}
+
+	public Object resolveArgument(MethodParameter parameter, 
+								  ModelAndViewContainer mavContainer,
+								  NativeWebRequest webRequest, 
+								  WebDataBinderFactory binderFactory) throws Exception {
+		
+		HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);
+		return ServletUriComponentsBuilder.fromServletMapping(request);
+	}
+
+}