SPR-7543 Add @PathVariables to the model

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

@@ -27,6 +27,7 @@ import org.springframework.web.bind.annotation.ValueConstants;
 import org.springframework.web.context.request.NativeWebRequest;
 import org.springframework.web.context.request.RequestAttributes;
 import org.springframework.web.method.annotation.support.AbstractNamedValueMethodArgumentResolver;
+import org.springframework.web.method.support.ModelAndViewContainer;
 import org.springframework.web.servlet.HandlerMapping;
 
 /**
@@ -73,6 +74,17 @@ public class PathVariableMethodArgumentResolver extends AbstractNamedValueMethod
 		throw new IllegalStateException("Could not find the URL template variable [" + name + "]");
 	}
 
+	@Override
+	protected void handleResolvedValue(Object arg, 
+									   String name, 
+									   MethodParameter parameter,
+									   ModelAndViewContainer mavContainer, 
+									   NativeWebRequest webRequest) {
+		if (mavContainer != null) {
+			mavContainer.addAttribute(name, arg);
+		}
+	}
+
 	private static class PathVariableNamedValueInfo extends NamedValueInfo {
 
 		private PathVariableNamedValueInfo(PathVariable annotation) {

org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerMethodAdapterIntegrationTests.java

@@ -293,7 +293,7 @@ public class RequestMappingHandlerMethodAdapterIntegrationTests {
 						 	@ModelAttribute OtherUser otherUser,
 						 	Model model) throws Exception {
 
-			model.addAttribute("cookie", cookie).addAttribute("pathvar", pathvar).addAttribute("header", header)
+			model.addAttribute("cookie", cookie).addAttribute("header", header)
 					.addAttribute("systemHeader", systemHeader).addAttribute("headerMap", headerMap)
 					.addAttribute("dateParam", dateParam).addAttribute("paramMap", paramMap)
 					.addAttribute("paramByConvention", paramByConvention).addAttribute("value", value)

org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/method/annotation/support/PathVariableMethodArgumentResolverTests.java

@@ -32,6 +32,7 @@ import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockHttpServletResponse;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.context.request.ServletWebRequest;
+import org.springframework.web.method.support.ModelAndViewContainer;
 import org.springframework.web.servlet.HandlerMapping;
 import org.springframework.web.servlet.mvc.method.annotation.support.PathVariableMethodArgumentResolver;
 
@@ -48,6 +49,8 @@ public class PathVariableMethodArgumentResolverTests {
 
 	private MethodParameter paramString;
 
+	private ModelAndViewContainer mavContainer;
+	
 	private ServletWebRequest webRequest;
 	
 	private MockHttpServletRequest request;
@@ -60,6 +63,7 @@ public class PathVariableMethodArgumentResolverTests {
 		paramNamedString = new MethodParameter(method, 0);
 		paramString = new MethodParameter(method, 1);
 
+		mavContainer = new ModelAndViewContainer();
 		request = new MockHttpServletRequest();
 		webRequest = new ServletWebRequest(request, new MockHttpServletResponse());
 	}
@@ -76,13 +80,14 @@ public class PathVariableMethodArgumentResolverTests {
 		uriTemplateVars.put("name", "value");
 		request.setAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE, uriTemplateVars);
 
-		String result = (String) resolver.resolveArgument(paramNamedString, null, webRequest, null);
-		assertEquals("value", result);
+		String result = (String) resolver.resolveArgument(paramNamedString, mavContainer, webRequest, null);
+		assertEquals("PathVariable not resolved correctly", "value", result);
+		assertEquals("PathVariable not added to the model", "value", mavContainer.getAttribute("name"));
 	}
 	
 	@Test(expected = IllegalStateException.class)
 	public void handleMissingValue() throws Exception {
-		resolver.resolveArgument(paramNamedString, null, webRequest, null);
+		resolver.resolveArgument(paramNamedString, mavContainer, webRequest, null);
 		fail("Unresolved path variable should lead to exception.");
 	}
 	

org.springframework.web/src/main/java/org/springframework/web/method/annotation/support/AbstractNamedValueMethodArgumentResolver.java

@@ -42,6 +42,7 @@ import org.springframework.web.method.support.ModelAndViewContainer;
  * <li>Obtain named value information for a method parameter
  * <li>Resolve names into argument values
  * <li>Handle missing argument values when argument values are required
+ * <li>Optionally handle a resolved value
  * </ul>
  * <p>A default value string can contain ${...} placeholders and Spring Expression Language #{...} expressions. 
  * For this to work a {@link ConfigurableBeanFactory} must be supplied to the class constructor.
@@ -87,17 +88,18 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 			else if (namedValueInfo.required) {
 				handleMissingValue(namedValueInfo.name, parameter);
 			}
-			arg = checkForNull(namedValueInfo.name, arg, paramType);
+			arg = handleNullValue(namedValueInfo.name, arg, paramType);
 		}
 
 		if (binderFactory != null) {
 			WebDataBinder binder = binderFactory.createBinder(webRequest, null, namedValueInfo.name);
-			return binder.convertIfNecessary(arg, paramType, parameter);
+			arg = binder.convertIfNecessary(arg, paramType, parameter);
 		}
-		else {
+		
+		handleResolvedValue(arg, namedValueInfo.name, parameter, mavContainer, webRequest);
+
 		return arg;
 	}
-	}
 
 	/**
 	 * Obtain the named value for the given method parameter.
@@ -170,7 +172,10 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 	 */
 	protected abstract void handleMissingValue(String name, MethodParameter parameter) throws ServletException;
 
-	private Object checkForNull(String name, Object value, Class<?> paramType) {
+	/**
+	 * A {@code null} results in a {@code false} value for {@code boolean}s or an exception for other primitives.
+	 */
+	private Object handleNullValue(String name, Object value, Class<?> paramType) {
 		if (value == null) {
 			if (Boolean.TYPE.equals(paramType)) {
 				return Boolean.FALSE;
@@ -184,6 +189,19 @@ public abstract class AbstractNamedValueMethodArgumentResolver implements Handle
 		return value;
 	}
 
+	/**
+	 * Invoked after a value is resolved.
+	 * @param arg the resolved argument value
+	 * @param name the argument name
+	 * @param parameter the argument parameter type
+	 * @param mavContainer the {@link ModelAndViewContainer}, which may be {@code null}
+	 * @param webRequest the current request
+	 */
+	protected void handleResolvedValue(Object arg, String name, MethodParameter parameter,
+			ModelAndViewContainer mavContainer, NativeWebRequest webRequest) {
+
+	}
+
 	/**
 	 * Represents the information about a named value, including name, whether it's required and a default value.
 	 */