From 416c282609423f260b54a06625d7261a5d5d8f5c Mon Sep 17 00:00:00 2001
From: Rossen Stoyanchev <rstoyanchev@vmware.com>
Date: Thu, 12 May 2011 15:03:36 +0000
Subject: [PATCH] Add method to allow further validation of request mapping
 infos at startup + other minor javadoc updates.

git-svn-id: https://src.springframework.org/svn/spring-framework/trunk@4297 50f2f4bb-b051-0410-bef5-90022cba6387
---
 .../annotation/WebMvcConfiguration.java       |  6 +-
 .../config/annotation/WebMvcConfigurer.java   | 10 ++--
 .../annotation/WebMvcConfigurerAdapter.java   | 10 ++--
 .../annotation/WebMvcConfigurerComposite.java | 58 +++++++++----------
 .../handler/AbstractHandlerMethodMapping.java |  8 +++
 .../RequestMappingHandlerAdapter.java         | 11 ++--
 .../RequestMappingHandlerMapping.java         | 13 +++++
 7 files changed, 69 insertions(+), 47 deletions(-)

diff --git a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfiguration.java b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfiguration.java
index fe38c31a3dd..0d843601341 100644
--- a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfiguration.java
+++ b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfiguration.java
@@ -59,7 +59,6 @@ import org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping;
 import org.springframework.web.servlet.handler.ConversionServiceExposingInterceptor;
 import org.springframework.web.servlet.handler.HandlerExceptionResolverComposite;
 import org.springframework.web.servlet.handler.MappedInterceptor;
-import org.springframework.web.servlet.handler.MappedInterceptors;
 import org.springframework.web.servlet.handler.SimpleUrlHandlerMapping;
 import org.springframework.web.servlet.mvc.Controller;
 import org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter;
@@ -88,7 +87,7 @@ import org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolv
  * </ul>
  *
  * <p><strong>Note:</strong> that the SimpleUrlHandlerMapping instances above will have empty URL maps and
- * hence no effect until explicitly configured via {@link WebMvcConfigurer}.
+ * hence no effect until explicitly configured via one of the {@link WebMvcConfigurer} callbacks.
  *
  * <p>Registers these handler adapters:
  * <ul>
@@ -108,7 +107,6 @@ import org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolv
  * <ul>
  * 	<li>{@link FormattingConversionService} for use with annotated controller methods and the spring:eval JSP tag.
  * 	<li>{@link Validator} for validating model attributes on annotated controller methods.
- * 	<li>{@link MappedInterceptors} containing a list Spring MVC lifecycle interceptors.
  * </ul>
  *
  * @see EnableWebMvc
@@ -128,7 +126,7 @@ class WebMvcConfiguration implements ApplicationContextAware, ServletContextAwar
 
 	@Autowired(required = false)
 	public void setConfigurers(List<WebMvcConfigurer> configurers) {
-		this.configurers.addConfigurers(configurers);
+		this.configurers.addWebMvcConfigurers(configurers);
 	}
 
 	public void setServletContext(ServletContext servletContext) {
diff --git a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurer.java b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurer.java
index 3ae69ce03fa..59e392fc5b6 100644
--- a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurer.java
+++ b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurer.java
@@ -54,7 +54,7 @@ public interface WebMvcConfigurer {
 	/**
 	 * Add {@link Converter}s and {@link Formatter}s in addition to the ones registered by default.
 	 */
-	void addFormatters(FormatterRegistry formatterRegistry);
+	void addFormatters(FormatterRegistry registry);
 
 	/**
 	 * Configure the list of {@link HttpMessageConverter}s to use when resolving method arguments or handling
@@ -102,20 +102,20 @@ public interface WebMvcConfigurer {
 	 * invocation. Interceptors can be registered to apply to all requests or limited to a set of path patterns.
 	 * @see InterceptorConfigurer
 	 */
-	void configureInterceptors(InterceptorConfigurer interceptorConfigurer);
+	void configureInterceptors(InterceptorConfigurer configurer);
 
 	/**
 	 * Configure the view controllers to use. A view controller is used to map a URL path directly to a view name.
 	 * This is convenient when a request does not require controller logic.
 	 */
-	void configureViewControllers(ViewControllerConfigurer viewControllerConfigurer);
+	void configureViewControllers(ViewControllerConfigurer configurer);
 
 	/**
 	 * Configure a handler for serving static resources such as images, js, and, css files through Spring MVC
 	 * including setting cache headers optimized for efficient loading in a web browser. Resources can be served
 	 * out of locations under web application root, from the classpath, and others.
 	 */
-	void configureResourceHandling(ResourceConfigurer resourceConfigurer);
+	void configureResourceHandling(ResourceConfigurer configurer);
 
 	/**
 	 * Configure a handler for delegating unhandled requests by forwarding to the Servlet container's default
@@ -123,6 +123,6 @@ public interface WebMvcConfigurer {
 	 * cleaner URLs (without a servlet prefix) but may need to still allow some requests (e.g. static resources)
 	 * to be handled by the Servlet container's default servlet.
 	 */
-	void configureDefaultServletHandling(DefaultServletHandlerConfigurer handlerConfigurer);
+	void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer);
 
 }
diff --git a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurerAdapter.java b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurerAdapter.java
index 671fc54f3cd..d3ef44d8c51 100644
--- a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurerAdapter.java
+++ b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurerAdapter.java
@@ -38,7 +38,7 @@ public abstract class WebMvcConfigurerAdapter implements WebMvcConfigurer {
 	 * {@inheritDoc}
 	 * <p>This implementation is empty.
 	 */
-	public void addFormatters(FormatterRegistry formatterRegistry) {
+	public void addFormatters(FormatterRegistry registry) {
 	}
 
 	/**
@@ -81,28 +81,28 @@ public abstract class WebMvcConfigurerAdapter implements WebMvcConfigurer {
 	 * {@inheritDoc}
 	 * <p>This implementation is empty.
 	 */
-	public void configureInterceptors(InterceptorConfigurer interceptorConfigurer) {
+	public void configureInterceptors(InterceptorConfigurer configurer) {
 	}
 
 	/**
 	 * {@inheritDoc}
 	 * <p>This implementation is empty.
 	 */
-	public void configureViewControllers(ViewControllerConfigurer viewControllerConfigurer) {
+	public void configureViewControllers(ViewControllerConfigurer configurer) {
 	}
 
 	/**
 	 * {@inheritDoc}
 	 * <p>This implementation is empty.
 	 */
-	public void configureResourceHandling(ResourceConfigurer resourceConfigurer) {
+	public void configureResourceHandling(ResourceConfigurer configurer) {
 	}
 
 	/**
 	 * {@inheritDoc}
 	 * <p>This implementation is empty.
 	 */
-	public void configureDefaultServletHandling(DefaultServletHandlerConfigurer handlerConfigurer) {
+	public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
 	}
 
 }
\ No newline at end of file
diff --git a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurerComposite.java b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurerComposite.java
index efc09b3ae1e..5a602174275 100644
--- a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurerComposite.java
+++ b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/annotation/WebMvcConfigurerComposite.java
@@ -36,74 +36,74 @@ import org.springframework.web.servlet.HandlerExceptionResolver;
  */
 class WebMvcConfigurerComposite implements WebMvcConfigurer {
 
-	private final List<WebMvcConfigurer> configurers = new ArrayList<WebMvcConfigurer>();
+	private final List<WebMvcConfigurer> delegates = new ArrayList<WebMvcConfigurer>();
 
-	public void addConfigurers(List<WebMvcConfigurer> configurers) {
+	public void addWebMvcConfigurers(List<WebMvcConfigurer> configurers) {
 		if (configurers != null) {
-			this.configurers.addAll(configurers);
+			this.delegates.addAll(configurers);
 		}
 	}
 
-	public void addFormatters(FormatterRegistry formatterRegistry) {
-		for (WebMvcConfigurer configurer : configurers) {
-			configurer.addFormatters(formatterRegistry);
+	public void addFormatters(FormatterRegistry registry) {
+		for (WebMvcConfigurer delegate : delegates) {
+			delegate.addFormatters(registry);
 		}
 	}
 
 	public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
-		for (WebMvcConfigurer configurer : configurers) {
-			configurer.configureMessageConverters(converters);
+		for (WebMvcConfigurer delegate : delegates) {
+			delegate.configureMessageConverters(converters);
 		}
 	}
 
 	public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
-		for (WebMvcConfigurer configurer : configurers) {
-			configurer.addArgumentResolvers(argumentResolvers);
+		for (WebMvcConfigurer delegate : delegates) {
+			delegate.addArgumentResolvers(argumentResolvers);
 		}
 	}
 
 	public void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {
-		for (WebMvcConfigurer configurer : configurers) {
-			configurer.addReturnValueHandlers(returnValueHandlers);
+		for (WebMvcConfigurer delegate : delegates) {
+			delegate.addReturnValueHandlers(returnValueHandlers);
 		}
 	}
 
 	public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {
-		for (WebMvcConfigurer configurer : configurers) {
-			configurer.configureHandlerExceptionResolvers(exceptionResolvers);
+		for (WebMvcConfigurer delegate : delegates) {
+			delegate.configureHandlerExceptionResolvers(exceptionResolvers);
 		}
 	}
 
-	public void configureInterceptors(InterceptorConfigurer interceptorRegistry) {
-		for (WebMvcConfigurer configurer : configurers) {
-			configurer.configureInterceptors(interceptorRegistry);
+	public void configureInterceptors(InterceptorConfigurer configurer) {
+		for (WebMvcConfigurer delegate : delegates) {
+			delegate.configureInterceptors(configurer);
 		}
 	}
 
-	public void configureViewControllers(ViewControllerConfigurer viewControllerConfigurer) {
-		for (WebMvcConfigurer configurer : configurers) {
-			configurer.configureViewControllers(viewControllerConfigurer);
+	public void configureViewControllers(ViewControllerConfigurer configurer) {
+		for (WebMvcConfigurer delegate : delegates) {
+			delegate.configureViewControllers(configurer);
 		}
 	}
 
-	public void configureResourceHandling(ResourceConfigurer resourceConfigurer) {
-		for (WebMvcConfigurer configurer : configurers) {
-			configurer.configureResourceHandling(resourceConfigurer);
+	public void configureResourceHandling(ResourceConfigurer configurer) {
+		for (WebMvcConfigurer delegate : delegates) {
+			delegate.configureResourceHandling(configurer);
 		}
 	}
 
-	public void configureDefaultServletHandling(DefaultServletHandlerConfigurer handlerConfigurer) {
-		for (WebMvcConfigurer configurer : configurers) {
-			configurer.configureDefaultServletHandling(handlerConfigurer);
+	public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
+		for (WebMvcConfigurer delegate : delegates) {
+			delegate.configureDefaultServletHandling(configurer);
 		}
 	}
 
 	public Validator getValidator() {
 		Map<WebMvcConfigurer, Validator> validators = new HashMap<WebMvcConfigurer, Validator>();
-		for (WebMvcConfigurer configurer : configurers) {
-			Validator validator = configurer.getValidator();
+		for (WebMvcConfigurer delegate : delegates) {
+			Validator validator = delegate.getValidator();
 			if (validator != null) {
-				validators.put(configurer, validator);
+				validators.put(delegate, validator);
 			}
 		}
 		if (validators.size() == 0) {
diff --git a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/handler/AbstractHandlerMethodMapping.java b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/handler/AbstractHandlerMethodMapping.java
index 502d43dce47..554fc456eaa 100644
--- a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/handler/AbstractHandlerMethodMapping.java
+++ b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/handler/AbstractHandlerMethodMapping.java
@@ -127,6 +127,7 @@ public abstract class AbstractHandlerMethodMapping<T> extends AbstractHandlerMap
 				detectHandlerMethods(beanName);
 			}
 		}
+		handlerMethodsInitialized(getHandlerMethods());
 	}
 
 	/**
@@ -136,6 +137,13 @@ public abstract class AbstractHandlerMethodMapping<T> extends AbstractHandlerMap
 	 */
 	protected abstract boolean isHandler(Class<?> beanType);
 
+	/**
+	 * Invoked after all handler methods found in beans of the current ApplicationContext have been registered.
+	 * @param handlerMethods a read-only map with mapping conditions (generic type {@code <T>}) and HandlerMethods.
+	 */
+	protected void handlerMethodsInitialized(Map<T, HandlerMethod> handlerMethods) {
+	}
+
 	/**
 	 * Detect and register handler methods for the specified handler.
 	 * @param handler the bean name of a handler or a handler instance
diff --git a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter.java b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter.java
index e18777431d5..fe01e9887fd 100644
--- a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter.java
+++ b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter.java
@@ -171,8 +171,10 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter i
 
 	/**
 	 * Set one or more custom argument resolvers to use with {@link RequestMapping}, {@link ModelAttribute}, and
-	 * {@link InitBinder} methods. Custom argument resolvers are given a chance to resolve argument values
-	 * ahead of the standard argument resolvers registered by default.
+	 * {@link InitBinder} methods. 
+	 * <p>Generally custom argument resolvers are invoked first. However this excludes 
+	 * default argument resolvers that rely on the presence of annotations (e.g. {@code @RequestParameter}, 
+	 * {@code @PathVariable}, etc.) Those resolvers can only be customized via {@link #setArgumentResolvers(List)}
 	 * <p>An existing {@link WebArgumentResolver} can either adapted with {@link ServletWebArgumentResolverAdapter}
 	 * or preferably converted to a {@link HandlerMethodArgumentResolver} instead.
 	 */
@@ -208,8 +210,9 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter i
 
 	/**
 	 * Set custom return value handlers to use to handle the return values of {@link RequestMapping} methods.
-	 * Custom return value handlers are given a chance to handle a return value before the standard
-	 * return value handlers registered by default.
+	 * <p>Generally custom return value handlers are invoked first. However this excludes default return value 
+	 * handlers that rely on the presence of annotations like {@code @ResponseBody}, {@code @ModelAttribute}, 
+	 * and others. Those handlers can only be customized via {@link #setReturnValueHandlers(List)}.
 	 * @param returnValueHandlers custom return value handlers for {@link RequestMapping} methods
 	 */
 	public void setCustomReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {
diff --git a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerMapping.java b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerMapping.java
index 9dfdf262e07..4f1810b408a 100644
--- a/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerMapping.java
+++ b/org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerMapping.java
@@ -17,6 +17,7 @@
 package org.springframework.web.servlet.mvc.method.annotation;
 
 import java.lang.reflect.Method;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Comparator;
 import java.util.HashSet;
@@ -24,6 +25,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+
 import javax.servlet.http.HttpServletRequest;
 
 import org.springframework.core.annotation.AnnotationUtils;
@@ -93,6 +95,17 @@ public class RequestMappingHandlerMapping extends AbstractHandlerMethodMapping<R
 		return AnnotationUtils.findAnnotation(beanType, Controller.class) != null;
 	}
 
+	@Override
+	protected void handlerMethodsInitialized(Map<RequestMappingInfo, HandlerMethod> handlerMethods) {
+		List<RequestMappingInfo> mappings = new ArrayList<RequestMappingInfo>(handlerMethods.keySet());
+		while (mappings.size() > 1) {
+			RequestMappingInfo mapping = mappings.remove(0);
+			for (RequestMappingInfo otherMapping : mappings) {
+				// further validate mapping conditions
+			}
+		}
+	}
+
 	/**
 	 * Provides a {@link RequestMappingInfo} for the given method. 
 	 * <p>Only {@link RequestMapping @RequestMapping}-annotated methods are considered.