Support HttpMessageConverter refs in mvc namespace

Issue: SPR-9469

spring-webmvc/src/main/java/org/springframework/web/servlet/config/AnnotationDrivenBeanDefinitionParser.java

@@ -397,10 +397,9 @@ class AnnotationDrivenBeanDefinitionParser implements BeanDefinitionParser {
 		ManagedList<? super Object> messageConverters = new ManagedList<Object>();
 		if (convertersElement != null) {
 			messageConverters.setSource(source);
-			for (Element converter : DomUtils.getChildElementsByTagName(convertersElement, "bean")) {
-				BeanDefinitionHolder beanDef = parserContext.getDelegate().parseBeanDefinitionElement(converter);
-				beanDef = parserContext.getDelegate().decorateBeanDefinitionIfRequired(converter, beanDef);
-				messageConverters.add(beanDef);
+			for (Element beanElement : DomUtils.getChildElementsByTagName(convertersElement, new String[] { "bean", "ref" })) {
+				Object object = parserContext.getDelegate().parsePropertySubElement(beanElement, null);
+				messageConverters.add(object);
 			}
 		}
 

spring-webmvc/src/main/resources/org/springframework/web/servlet/config/spring-mvc-3.2.xsd

@@ -33,13 +33,22 @@
 					</xsd:annotation>
 					<xsd:complexType>
 						<xsd:sequence>
-							<xsd:element ref="beans:bean" minOccurs="1" maxOccurs="unbounded">
-								<xsd:annotation>
-									<xsd:documentation><![CDATA[
-	The HttpMessageConverter bean definition.
-									]]></xsd:documentation>
-								</xsd:annotation>
-							</xsd:element>
+							<xsd:choice maxOccurs="unbounded">
+								<xsd:element ref="beans:bean">
+									<xsd:annotation>
+										<xsd:documentation><![CDATA[
+		An HttpMessageConverter bean definition.
+										]]></xsd:documentation>
+									</xsd:annotation>
+								</xsd:element>
+								<xsd:element ref="beans:ref">
+									<xsd:annotation>
+										<xsd:documentation><![CDATA[
+		A reference to an HttpMessageConverter bean.
+										]]></xsd:documentation>
+									</xsd:annotation>
+								</xsd:element>
+							</xsd:choice>
 						</xsd:sequence>
 						<xsd:attribute name="register-defaults" type="xsd:boolean" default="true">
 							<xsd:annotation>

spring-webmvc/src/test/resources/org/springframework/web/servlet/config/mvc-config-message-converters-defaults-off.xml

@@ -2,14 +2,17 @@
 <beans xmlns="http://www.springframework.org/schema/beans"
     xmlns:mvc="http://www.springframework.org/schema/mvc"
 	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
-		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd">
+	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
+		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd">
 
 	<mvc:annotation-driven>
 		<mvc:message-converters register-defaults="false">
-			<bean class="org.springframework.http.converter.StringHttpMessageConverter"/>
-			<bean class="org.springframework.http.converter.ResourceHttpMessageConverter"/>
+			<ref bean="stringConverter" />
+			<ref bean="resourceConverter" />
 		</mvc:message-converters>
 	</mvc:annotation-driven>
 
+	<bean id="stringConverter" class="org.springframework.http.converter.StringHttpMessageConverter"/>
+	<bean id="resourceConverter" class="org.springframework.http.converter.ResourceHttpMessageConverter"/>
+
 </beans>