@RequestParam and co support placeholders and expressions in their defaultValue attributes (SPR-5922); @Value expressions supported as MVC handler method arguments as well (against request scope)

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/annotation/AnnotationMethodHandlerAdapter.java

@@ -46,6 +46,11 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
 import org.springframework.beans.BeanUtils;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.BeanFactoryAware;
+import org.springframework.beans.factory.config.BeanExpressionContext;
+import org.springframework.beans.factory.config.BeanExpressionResolver;
+import org.springframework.beans.factory.config.ConfigurableBeanFactory;
 import org.springframework.core.LocalVariableTableParameterNameDiscoverer;
 import org.springframework.core.ParameterNameDiscoverer;
 import org.springframework.core.annotation.AnnotationUtils;
@@ -88,6 +93,7 @@ import org.springframework.web.bind.support.SessionAttributeStore;
 import org.springframework.web.bind.support.WebArgumentResolver;
 import org.springframework.web.bind.support.WebBindingInitializer;
 import org.springframework.web.context.request.NativeWebRequest;
+import org.springframework.web.context.request.RequestScope;
 import org.springframework.web.context.request.ServletWebRequest;
 import org.springframework.web.servlet.HandlerAdapter;
 import org.springframework.web.servlet.HandlerMapping;
@@ -120,18 +126,16 @@ import org.springframework.web.util.WebUtils;
  * @see #setWebBindingInitializer
  * @see #setSessionAttributeStore
  */
-public class AnnotationMethodHandlerAdapter extends WebContentGenerator implements HandlerAdapter {
+public class AnnotationMethodHandlerAdapter extends WebContentGenerator implements HandlerAdapter, BeanFactoryAware {
 
 	/**
 	 * Log category to use when no mapped handler is found for a request.
-	 *
 	 * @see #pageNotFoundLogger
 	 */
 	public static final String PAGE_NOT_FOUND_LOG_CATEGORY = "org.springframework.web.servlet.PageNotFound";
 
 	/**
 	 * Additional logger to use when no mapped handler is found for a request.
-	 *
 	 * @see #PAGE_NOT_FOUND_LOG_CATEGORY
 	 */
 	protected static final Log pageNotFoundLogger = LogFactory.getLog(PAGE_NOT_FOUND_LOG_CATEGORY);
@@ -156,13 +160,17 @@ public class AnnotationMethodHandlerAdapter extends WebContentGenerator implemen
 
 	private ModelAndViewResolver[] customModelAndViewResolvers;
 
-	private final Map<Class<?>, ServletHandlerMethodResolver> methodResolverCache =
-			new ConcurrentHashMap<Class<?>, ServletHandlerMethodResolver>();
-
 	private HttpMessageConverter<?>[] messageConverters =
 			new HttpMessageConverter[] {new ByteArrayHttpMessageConverter(), new StringHttpMessageConverter(),
 					new FormHttpMessageConverter(), new SourceHttpMessageConverter()};
 
+	private ConfigurableBeanFactory beanFactory;
+
+	private BeanExpressionContext expressionContext;
+
+	private final Map<Class<?>, ServletHandlerMethodResolver> methodResolverCache =
+			new ConcurrentHashMap<Class<?>, ServletHandlerMethodResolver>();
+
 
 	public AnnotationMethodHandlerAdapter() {
 		// no restriction of HTTP methods by default
@@ -318,6 +326,13 @@ public class AnnotationMethodHandlerAdapter extends WebContentGenerator implemen
 		this.messageConverters = messageConverters;
 	}
 
+	public void setBeanFactory(BeanFactory beanFactory) {
+		if (beanFactory instanceof ConfigurableBeanFactory) {
+			this.beanFactory = (ConfigurableBeanFactory) beanFactory;
+			this.expressionContext = new BeanExpressionContext(this.beanFactory, new RequestScope());
+		}
+	}
+
 
 	public boolean supports(Object handler) {
 		return getMethodResolver(handler).hasHandlerMethods();
@@ -595,6 +610,19 @@ public class AnnotationMethodHandlerAdapter extends WebContentGenerator implemen
 			throw new HttpSessionRequiredException(message);
 		}
 
+		@Override
+		protected Object resolveDefaultValue(String value) {
+			if (beanFactory == null) {
+				return value;
+			}
+			String placeholdersResolved = beanFactory.resolveEmbeddedValue(value);
+			BeanExpressionResolver exprResolver = beanFactory.getBeanExpressionResolver();
+			if (exprResolver == null) {
+				return value;
+			}
+			return exprResolver.evaluate(placeholdersResolved, expressionContext);
+		}
+
 		@Override
 		protected HttpInputMessage createHttpInputMessage(NativeWebRequest webRequest) throws Exception {
 			HttpServletRequest servletRequest = (HttpServletRequest) webRequest.getNativeRequest();

org.springframework.web.servlet/src/test/java/org/springframework/web/servlet/mvc/annotation/ServletAnnotationControllerTests.java

@@ -51,11 +51,12 @@ import org.junit.Test;
 import org.springframework.aop.framework.autoproxy.DefaultAdvisorAutoProxyCreator;
 import org.springframework.aop.interceptor.SimpleTraceInterceptor;
 import org.springframework.aop.support.DefaultPointcutAdvisor;
-import org.springframework.beans.BeansException;
 import org.springframework.beans.DerivedTestBean;
 import org.springframework.beans.ITestBean;
 import org.springframework.beans.TestBean;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.beans.propertyeditors.CustomDateEditor;
 import org.springframework.context.annotation.AnnotationConfigUtils;
@@ -186,7 +187,7 @@ public class ServletAnnotationControllerTests {
 	}
 
 	@Test
-	public void defaultParamMissing() throws Exception {
+	public void defaultParameters() throws Exception {
 		initServlet(DefaultValueParamController.class);
 
 		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/myPath.do");
@@ -195,6 +196,23 @@ public class ServletAnnotationControllerTests {
 		assertEquals("foo-bar", response.getContentAsString());
 	}
 
+	@Test
+	public void defaultExpressionParameters() throws Exception {
+		initServlet(DefaultExpressionValueParamController.class);
+
+		MockHttpServletRequest request = new MockHttpServletRequest("GET", "/myApp/myPath.do");
+		request.setContextPath("/myApp");
+		MockHttpServletResponse response = new MockHttpServletResponse();
+		System.setProperty("myHeader", "bar");
+		try {
+			servlet.service(request, response);
+		}
+		finally {
+			System.clearProperty("myHeader");
+		}
+		assertEquals("foo-bar-/myApp", response.getContentAsString());
+	}
+
 	@Test
 	public void methodNotAllowed() throws Exception {
 		initServlet(MethodNotAllowedController.class);
@@ -281,13 +299,15 @@ public class ServletAnnotationControllerTests {
 		doTestAdaptedHandleMethods(MyAdaptedController3.class);
 	}
 
-	private void initServlet(final Class<?> controllerclass) throws ServletException {
+	private void initServlet(final Class<?> controllerClass) throws ServletException {
 		servlet = new DispatcherServlet() {
 			@Override
-			protected WebApplicationContext createWebApplicationContext(WebApplicationContext parent)
-					throws BeansException {
+			protected WebApplicationContext createWebApplicationContext(WebApplicationContext parent) {
 				GenericWebApplicationContext wac = new GenericWebApplicationContext();
-				wac.registerBeanDefinition("controller", new RootBeanDefinition(controllerclass));
+				wac.registerBeanDefinition("controller", new RootBeanDefinition(controllerClass));
+				RootBeanDefinition ppc = new RootBeanDefinition(PropertyPlaceholderConfigurer.class);
+				ppc.getPropertyValues().addPropertyValue("properties", "myKey=foo");
+				wac.registerBeanDefinition("ppc", ppc);
 				wac.refresh();
 				return wac;
 			}
@@ -1615,6 +1635,18 @@ public class ServletAnnotationControllerTests {
 		}
 	}
 
+	@Controller
+	public static class DefaultExpressionValueParamController {
+
+		@RequestMapping("/myPath.do")
+		public void myHandle(@RequestParam(value = "id", defaultValue = "${myKey}") String id,
+				@RequestHeader(defaultValue = "#{systemProperties.myHeader}") String header,
+				@Value("#{request.contextPath}") String contextPath, HttpServletResponse response)
+				throws IOException {
+			response.getWriter().write(String.valueOf(id) + "-" + String.valueOf(header) + "-" + contextPath);
+		}
+	}
+
 	@Controller
 	public static class MethodNotAllowedController {