SPR-8234 Switch to strongly typed custom argument resolvers property

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/AnnotationDrivenBeanDefinitionParser.java

@@ -16,13 +16,20 @@
 
 package org.springframework.web.servlet.config;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import org.springframework.beans.factory.config.BeanDefinitionHolder;
 import org.springframework.beans.factory.support.ManagedList;
+import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.beans.factory.xml.BeanDefinitionParser;
 import org.springframework.beans.factory.xml.ParserContext;
 import org.springframework.context.config.AbstractSpecificationBeanDefinitionParser;
 import org.springframework.context.config.FeatureSpecification;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.xml.DomUtils;
+import org.springframework.web.bind.support.WebArgumentResolver;
+import org.springframework.web.servlet.mvc.method.annotation.support.ServletWebArgumentResolverAdapter;
 import org.w3c.dom.Element;
 
 /**
@@ -63,14 +70,15 @@ class AnnotationDrivenBeanDefinitionParser extends AbstractSpecificationBeanDefi
 		}
 		Element resolversElement = DomUtils.getChildElementByTagName(element, "argument-resolvers");
 		if (resolversElement != null) {
-			spec.argumentResolvers(extractBeanSubElements(resolversElement, parserContext));
+			ManagedList<BeanDefinitionHolder> beanDefs = extractBeanSubElements(resolversElement, parserContext);
+			spec.argumentResolvers(wrapWebArgumentResolverBeanDefs(beanDefs));
 		}
 
 		return spec;
 	}
 
-	private ManagedList<? super Object> extractBeanSubElements(Element parentElement, ParserContext parserContext) {
-		ManagedList<? super Object> list = new ManagedList<Object>();
+	private ManagedList<BeanDefinitionHolder> extractBeanSubElements(Element parentElement, ParserContext parserContext) {
+		ManagedList<BeanDefinitionHolder> list = new ManagedList<BeanDefinitionHolder>();
 		list.setSource(parserContext.extractSource(parentElement));
 		for (Element beanElement : DomUtils.getChildElementsByTagName(parentElement, "bean")) {
 			BeanDefinitionHolder beanDef = parserContext.getDelegate().parseBeanDefinitionElement(beanElement);
@@ -80,4 +88,23 @@ class AnnotationDrivenBeanDefinitionParser extends AbstractSpecificationBeanDefi
 		return list;
 	}
 
+	private ManagedList<BeanDefinitionHolder> wrapWebArgumentResolverBeanDefs(List<BeanDefinitionHolder> beanDefs) {
+		ManagedList<BeanDefinitionHolder> result = new ManagedList<BeanDefinitionHolder>();
+		
+		for (BeanDefinitionHolder beanDef : beanDefs) {
+			String className = beanDef.getBeanDefinition().getBeanClassName();
+			Class<?> clazz = ClassUtils.resolveClassName(className, ClassUtils.getDefaultClassLoader());
+			
+			if (WebArgumentResolver.class.isAssignableFrom(clazz)) {
+				RootBeanDefinition adapter = new RootBeanDefinition(ServletWebArgumentResolverAdapter.class);
+				adapter.getConstructorArgumentValues().addIndexedArgumentValue(0, beanDef);
+				result.add(new BeanDefinitionHolder(adapter, beanDef.getBeanName() + "Adapter"));
+			}
+			else {
+				result.add(beanDef);
+			}
+		}
+		
+		return result;
+	}
 }

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/MvcAnnotationDriven.java

@@ -15,6 +15,7 @@
  */
 package org.springframework.web.servlet.config;
 
+import org.springframework.beans.factory.config.BeanDefinitionHolder;
 import org.springframework.beans.factory.parsing.ProblemCollector;
 import org.springframework.beans.factory.support.ManagedList;
 import org.springframework.context.config.AbstractFeatureSpecification;
@@ -145,8 +146,8 @@ public final class MvcAnnotationDriven extends AbstractFeatureSpecification {
 		return this;
 	}
 
-	void messageConverters(ManagedList<? super Object> messageConverters) {
-		this.messageConverters = messageConverters;
+	void messageConverters(ManagedList<BeanDefinitionHolder> converterBeanDefinitions) {
+		this.messageConverters.addAll(converterBeanDefinitions);
 	}
 
 	ManagedList<?> messageConverters() {
@@ -183,8 +184,8 @@ public final class MvcAnnotationDriven extends AbstractFeatureSpecification {
 		return this;
 	}
 
-	void argumentResolvers(ManagedList<? super Object> argumentResolvers) {
-		this.argumentResolvers = argumentResolvers;
+	void argumentResolvers(ManagedList<BeanDefinitionHolder> resolverBeanDefinitions) {
+		this.argumentResolvers.addAll(resolverBeanDefinitions);
 	}
 
 	ManagedList<?> argumentResolvers() {

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

@@ -175,28 +175,13 @@ public class RequestMappingHandlerMethodAdapter extends AbstractHandlerMethodAda
 	 * 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.
-	 * <p>Argument resolvers of type {@link HandlerMethodArgumentResolver} and {@link WebArgumentResolver} are
-	 * accepted with instances of the latter adapted via {@link ServletWebArgumentResolverAdapter}. For new
-	 * implementations {@link HandlerMethodArgumentResolver} should be preferred over {@link WebArgumentResolver}.
+	 * <p>An existing {@link WebArgumentResolver} can either adapted with {@link ServletWebArgumentResolverAdapter} 
+	 * or preferably converted to a {@link HandlerMethodArgumentResolver} instead. 
 	 */
-	public void setCustomArgumentResolvers(List<?> argumentResolvers) {
-		if (argumentResolvers == null) {
-			return;
-		}
-		List<HandlerMethodArgumentResolver> adaptedResolvers = new ArrayList<HandlerMethodArgumentResolver>();
-		for (Object resolver : argumentResolvers) {
-			if (resolver instanceof WebArgumentResolver) {
-				adaptedResolvers.add(new ServletWebArgumentResolverAdapter((WebArgumentResolver) resolver));
-			}
-			else if (resolver instanceof HandlerMethodArgumentResolver) {
-				adaptedResolvers.add((HandlerMethodArgumentResolver) resolver);
-			}
-			else {
-				throw new IllegalArgumentException(
-						"An argument resolver must be a HandlerMethodArgumentResolver or a WebArgumentResolver");
-			}
+	public void setCustomArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
+		if (argumentResolvers != null) {
+			this.customArgumentResolvers.addAll(argumentResolvers);
 		}
-		this.customArgumentResolvers.addAll(adaptedResolvers);
 	}
 	
 	/**

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

@@ -115,28 +115,13 @@ public class RequestMappingHandlerMethodExceptionResolver extends AbstractHandle
 	/**
 	 * Set one or more custom argument resolvers to use with {@link ExceptionHandler} methods. Custom argument resolvers
 	 * are given a chance to resolve argument values ahead of the standard argument resolvers registered by default.
-	 * <p>Argument resolvers of type {@link HandlerMethodArgumentResolver} and {@link WebArgumentResolver} are
-	 * accepted with instances of the latter adapted via {@link ServletWebArgumentResolverAdapter}. For new
-	 * implementations {@link HandlerMethodArgumentResolver} should be preferred over {@link WebArgumentResolver}.
+	 * <p>An existing {@link WebArgumentResolver} can either adapted with {@link ServletWebArgumentResolverAdapter} 
+	 * or preferably converted to a {@link HandlerMethodArgumentResolver} instead. 
 	 */
-	public void setCustomArgumentResolvers(List<?> argumentResolvers) {
-		if (argumentResolvers == null) {
-			return;
-		}
-		List<HandlerMethodArgumentResolver> adaptedResolvers = new ArrayList<HandlerMethodArgumentResolver>();
-		for (Object resolver : argumentResolvers) {
-			if (resolver instanceof WebArgumentResolver) {
-				adaptedResolvers.add(new ServletWebArgumentResolverAdapter((WebArgumentResolver) resolver));
-			}
-			else if (resolver instanceof HandlerMethodArgumentResolver) {
-				adaptedResolvers.add((HandlerMethodArgumentResolver) resolver);
-			}
-			else {
-				throw new IllegalArgumentException(
-						"An argument resolver must be a HandlerMethodArgumentResolver or a WebArgumentResolver");
-			}
+	public void setCustomArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
+		if (argumentResolvers != null) {
+			this.customArgumentResolvers.addAll(argumentResolvers);
 		}
-		this.customArgumentResolvers.addAll(adaptedResolvers);
 	}	
 
 	/**

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

@@ -122,6 +122,7 @@ import org.springframework.web.context.WebApplicationContext;
 import org.springframework.web.context.request.NativeWebRequest;
 import org.springframework.web.context.request.WebRequest;
 import org.springframework.web.context.support.GenericWebApplicationContext;
+import org.springframework.web.method.support.HandlerMethodArgumentResolver;
 import org.springframework.web.multipart.support.StringMultipartFileEditor;
 import org.springframework.web.servlet.DispatcherServlet;
 import org.springframework.web.servlet.ModelAndView;
@@ -129,6 +130,7 @@ import org.springframework.web.servlet.View;
 import org.springframework.web.servlet.ViewResolver;
 import org.springframework.web.servlet.mvc.annotation.ModelAndViewResolver;
 import org.springframework.web.servlet.mvc.annotation.ResponseStatusExceptionResolver;
+import org.springframework.web.servlet.mvc.method.annotation.support.ServletWebArgumentResolverAdapter;
 import org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver;
 import org.springframework.web.servlet.view.InternalResourceViewResolver;
 import org.springframework.web.util.NestedServletException;
@@ -570,7 +572,8 @@ public class ServletHandlerMethodTests {
 				wac.registerBeanDefinition("viewResolver", new RootBeanDefinition(TestViewResolver.class));
 				RootBeanDefinition adapterDef = new RootBeanDefinition(RequestMappingHandlerMethodAdapter.class);
 				adapterDef.getPropertyValues().add("webBindingInitializer", new MyWebBindingInitializer());
-				WebArgumentResolver[] argumentResolvers = new WebArgumentResolver[] {new MySpecialArgumentResolver()};
+				List<HandlerMethodArgumentResolver> argumentResolvers = new ArrayList<HandlerMethodArgumentResolver>();
+				argumentResolvers.add(new ServletWebArgumentResolverAdapter(new MySpecialArgumentResolver()));
 				adapterDef.getPropertyValues().add("customArgumentResolvers", argumentResolvers);
 				wac.registerBeanDefinition("handlerAdapter", adapterDef);
 			}