Allow configuring custom argument types

The WebSocket messaging namespace now exposes configuration options for
custom argument resolvers and return value handlers.

Issue: SPR-12217

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

@@ -32,7 +32,9 @@ import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.beans.factory.config.CustomScopeConfigurer;
 import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
+import org.springframework.core.MethodParameter;
 import org.springframework.core.io.ClassPathResource;
+import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageHandler;
 import org.springframework.messaging.converter.ByteArrayMessageConverter;
 import org.springframework.messaging.converter.CompositeMessageConverter;
@@ -41,6 +43,8 @@ import org.springframework.messaging.converter.DefaultContentTypeResolver;
 import org.springframework.messaging.converter.MappingJackson2MessageConverter;
 import org.springframework.messaging.converter.MessageConverter;
 import org.springframework.messaging.converter.StringMessageConverter;
+import org.springframework.messaging.handler.invocation.HandlerMethodArgumentResolver;
+import org.springframework.messaging.handler.invocation.HandlerMethodReturnValueHandler;
 import org.springframework.messaging.simp.SimpMessagingTemplate;
 import org.springframework.messaging.simp.annotation.support.SimpAnnotationMethodMessageHandler;
 import org.springframework.messaging.simp.broker.SimpleBrokerMessageHandler;
@@ -336,6 +340,23 @@ public class MessageBrokerBeanDefinitionParserTests {
 		assertFalse(this.appContext.containsBean("brokerChannelExecutor"));
 	}
 
+	@Test
+	public void customArgumentAndReturnValueTypes() {
+		loadBeanDefinitions("websocket-config-broker-custom-argument-and-return-value-types.xml");
+
+		SimpAnnotationMethodMessageHandler handler = this.appContext.getBean(SimpAnnotationMethodMessageHandler.class);
+
+		List<HandlerMethodArgumentResolver> customResolvers = handler.getCustomArgumentResolvers();
+		assertEquals(2, customResolvers.size());
+		assertTrue(handler.getArgumentResolvers().contains(customResolvers.get(0)));
+		assertTrue(handler.getArgumentResolvers().contains(customResolvers.get(1)));
+
+		List<HandlerMethodReturnValueHandler> customHandlers = handler.getCustomReturnValueHandlers();
+		assertEquals(2, customHandlers.size());
+		assertTrue(handler.getReturnValueHandlers().contains(customHandlers.get(0)));
+		assertTrue(handler.getReturnValueHandlers().contains(customHandlers.get(1)));
+	}
+
 	@Test
 	public void messageConverters() {
 		loadBeanDefinitions("websocket-config-broker-converters.xml");
@@ -396,3 +417,30 @@ public class MessageBrokerBeanDefinitionParserTests {
 	}
 
 }
+
+class CustomArgumentResolver implements HandlerMethodArgumentResolver {
+
+	@Override
+	public boolean supportsParameter(MethodParameter parameter) {
+		return false;
+	}
+
+	@Override
+	public Object resolveArgument(MethodParameter parameter, Message<?> message) throws Exception {
+		return null;
+	}
+
+}
+
+class CustomReturnValueHandler implements HandlerMethodReturnValueHandler {
+
+	@Override
+	public boolean supportsReturnType(MethodParameter returnType) {
+		return false;
+	}
+
+	@Override
+	public void handleReturnValue(Object returnValue, MethodParameter returnType, Message<?> message) throws Exception {
+
+	}
+}

spring-websocket/src/test/resources/org/springframework/web/socket/config/websocket-config-broker-custom-argument-and-return-value-types.xml

@@ -0,0 +1,30 @@
+<beans xmlns="http://www.springframework.org/schema/beans"
+	   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	   xmlns:websocket="http://www.springframework.org/schema/websocket"
+	   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:stomp-endpoint path="/foo,/bar">
+			<websocket:handshake-handler ref="myHandler"/>
+		</websocket:stomp-endpoint>
+		<websocket:simple-broker prefix="/topic"/>
+		<websocket:argument-resolvers>
+			<bean class="org.springframework.web.socket.config.CustomArgumentResolver" />
+			<ref bean="myArgumentResolver" />
+		</websocket:argument-resolvers>
+		<websocket:return-value-handlers>
+			<bean class="org.springframework.web.socket.config.CustomReturnValueHandler" />
+			<ref bean="myReturnValueHandler" />
+		</websocket:return-value-handlers>
+	</websocket:message-broker>
+
+	<bean id="myHandler" class="org.springframework.web.socket.config.TestHandshakeHandler"/>
+
+	<bean id="myInterceptor" class="org.springframework.web.socket.config.TestChannelInterceptor"/>
+
+	<bean id="myArgumentResolver" class="org.springframework.web.socket.config.CustomArgumentResolver" />
+
+	<bean id="myReturnValueHandler" class="org.springframework.web.socket.config.CustomReturnValueHandler" />
+
+</beans>