Allow Validator config in XML websocket namespace

This commit adds a new "validator" XML attribute to the
`<websocket:message-broker/>` element. This allows configuring a
specific Validator to be used for payload validation.

Issue: SPR-13996

spring-webmvc/src/test/java/org/springframework/web/servlet/config/MvcNamespaceTests.java

@@ -853,6 +853,7 @@ public class MvcNamespaceTests {
 		ContentNegotiationManager manager = (ContentNegotiationManager) accessor.getPropertyValue(beanName);
 		assertNotNull(manager);
 		assertSame(manager, this.appContext.getBean(ContentNegotiationManager.class));
+		assertSame(manager, this.appContext.getBean("mvcContentNegotiationManager"));
 	}
 
 	@Test

spring-websocket/src/main/java/org/springframework/web/socket/config/MessageBrokerBeanDefinitionParser.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -109,6 +109,9 @@ class MessageBrokerBeanDefinitionParser implements BeanDefinitionParser {
 	private static final boolean jackson2Present = ClassUtils.isPresent(
 			"com.fasterxml.jackson.databind.ObjectMapper", MessageBrokerBeanDefinitionParser.class.getClassLoader());
 
+	private static final boolean javaxValidationPresent =
+			ClassUtils.isPresent("javax.validation.Validator", MessageBrokerBeanDefinitionParser.class.getClassLoader());
+
 
 	@Override
 	public BeanDefinition parse(Element element, ParserContext context) {
@@ -516,6 +519,11 @@ class MessageBrokerBeanDefinitionParser implements BeanDefinitionParser {
 			beanDef.getPropertyValues().add("pathMatcher", new RuntimeBeanReference(pathMatcherRef));
 		}
 
+		RuntimeBeanReference validatorRef = getValidator(messageBrokerElement, source, context);
+		if (validatorRef != null) {
+			beanDef.getPropertyValues().add("validator", validatorRef);
+		}
+
 		Element resolversElement = DomUtils.getChildElementByTagName(messageBrokerElement, "argument-resolvers");
 		if (resolversElement != null) {
 			values.add("customArgumentResolvers", extractBeanSubElements(resolversElement, context));
@@ -529,6 +537,24 @@ class MessageBrokerBeanDefinitionParser implements BeanDefinitionParser {
 		registerBeanDef(beanDef, context, source);
 	}
 
+	private RuntimeBeanReference getValidator(Element messageBrokerElement, Object source, ParserContext parserContext) {
+		if (messageBrokerElement.hasAttribute("validator")) {
+			return new RuntimeBeanReference(messageBrokerElement.getAttribute("validator"));
+		}
+		else if (javaxValidationPresent) {
+			RootBeanDefinition validatorDef = new RootBeanDefinition(
+					"org.springframework.validation.beanvalidation.OptionalValidatorFactoryBean");
+			validatorDef.setSource(source);
+			validatorDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
+			String validatorName = parserContext.getReaderContext().registerWithGeneratedName(validatorDef);
+			parserContext.registerComponent(new BeanComponentDefinition(validatorDef, validatorName));
+			return new RuntimeBeanReference(validatorName);
+		}
+		else {
+			return null;
+		}
+	}
+
 	private ManagedList<Object> extractBeanSubElements(Element parentElement, ParserContext parserContext) {
 		ManagedList<Object> list = new ManagedList<Object>();
 		list.setSource(parserContext.extractSource(parentElement));

spring-websocket/src/main/resources/org/springframework/web/socket/config/spring-websocket-4.3.xsd

@@ -21,7 +21,7 @@
 			<xsd:annotation>
 				<xsd:documentation><![CDATA[
 	A path that maps a particular request to a handler.
-	Exact path mapping URIs (such as "/myPath") are supported as well as Ant-stype path patterns (such as /myPath/**).
+	Exact path mapping URIs (such as "/myPath") are supported as well as Ant-type path patterns (such as /myPath/**).
                 ]]></xsd:documentation>
 			</xsd:annotation>
 		</xsd:attribute>
@@ -919,6 +919,13 @@
 					]]></xsd:documentation>
 				</xsd:annotation>
 			</xsd:attribute>
+			<xsd:attribute name="validator" type="xsd:string">
+			<xsd:annotation>
+				<xsd:documentation><![CDATA[
+	The bean name of the Validator instance used for validating @Payload arguments.
+				]]></xsd:documentation>
+			</xsd:annotation>
+		</xsd:attribute>
 		</xsd:complexType>
 	</xsd:element>
 </xsd:schema>

spring-websocket/src/test/java/org/springframework/web/socket/config/MessageBrokerBeanDefinitionParserTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -60,6 +60,8 @@ import org.springframework.mock.web.test.MockServletContext;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler;
 import org.springframework.util.MimeTypeUtils;
+import org.springframework.validation.Errors;
+import org.springframework.validation.Validator;
 import org.springframework.web.HttpRequestHandler;
 import org.springframework.web.context.support.GenericWebApplicationContext;
 import org.springframework.web.servlet.HandlerMapping;
@@ -356,6 +358,14 @@ public class MessageBrokerBeanDefinitionParserTests {
 	public void customChannels() {
 		loadBeanDefinitions("websocket-config-broker-customchannels.xml");
 
+		SimpAnnotationMethodMessageHandler annotationMethodMessageHandler =
+				this.appContext.getBean(SimpAnnotationMethodMessageHandler.class);
+
+		Validator validator = annotationMethodMessageHandler.getValidator();
+		assertNotNull(validator);
+		assertSame(this.appContext.getBean("myValidator"), validator);
+		assertThat(validator, Matchers.instanceOf(TestValidator.class));
+
 		List<Class<? extends MessageHandler>> subscriberTypes =
 				Arrays.<Class<? extends MessageHandler>>asList(SimpAnnotationMethodMessageHandler.class,
 						UserDestinationMessageHandler.class, SimpleBrokerMessageHandler.class);
@@ -520,3 +530,13 @@ class TestWebSocketHandlerDecorator extends WebSocketHandlerDecorator {
 
 class TestStompErrorHandler extends StompSubProtocolErrorHandler {
 }
+
+class TestValidator implements Validator {
+	@Override
+	public boolean supports(Class<?> clazz) {
+		return false;
+	}
+
+	@Override
+	public void validate(Object target, Errors errors) { }
+}

spring-websocket/src/test/resources/org/springframework/web/socket/config/websocket-config-broker-customchannels.xml

@@ -4,7 +4,7 @@
 	   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
 		http://www.springframework.org/schema/websocket http://www.springframework.org/schema/websocket/spring-websocket.xsd">
 
-	<websocket:message-broker application-destination-prefix="/app" user-destination-prefix="/personal">
+	<websocket:message-broker application-destination-prefix="/app" user-destination-prefix="/personal" validator="myValidator">
 		<websocket:stomp-endpoint path="/foo,/bar">
 			<websocket:handshake-handler ref="myHandler"/>
 		</websocket:stomp-endpoint>
@@ -31,4 +31,6 @@
 
 	<bean id="myInterceptor" class="org.springframework.web.socket.config.TestChannelInterceptor"/>
 
+	<bean id="myValidator" class="org.springframework.web.socket.config.TestValidator"/>
+
 </beans>