INT-1180 Added a 'requiresReply' header. The default value is FALSE, but Gateway request Messages now have this value set to true whenever the invoked method has a non-void return. This will trigger a MessageHandlingException instead of a timeout downstream if no reply is produced by an instance of AbstractReplyProducingMessageHandler.

spring-integration-core/src/main/java/org/springframework/integration/MessageHeaders.java

@@ -58,6 +58,8 @@ public final class MessageHeaders implements Map<String, Object>, Serializable {
 
 	public static final String CORRELATION_ID = PREFIX + "correlationId";
 
+	public static final String REQUIRES_REPLY = PREFIX + "requiresReply";
+
 	public static final String REPLY_CHANNEL = PREFIX + "replyChannel";
 
 	public static final String ERROR_CHANNEL = PREFIX + "errorChannel";
@@ -98,6 +100,11 @@ public final class MessageHeaders implements Map<String, Object>, Serializable {
 		return this.get(REPLY_CHANNEL);
 	}
 
+	public boolean getRequiresReply() {
+		Boolean headerValue = this.get(REQUIRES_REPLY, Boolean.class);
+		return (headerValue != null && headerValue);
+	}
+
 	public Object getErrorChannel() {
 		return this.get(ERROR_CHANNEL);
 	}

spring-integration-core/src/main/java/org/springframework/integration/core/MessageBuilder.java

@@ -167,6 +167,10 @@ public final class MessageBuilder<T> {
 		return this.setHeader(MessageHeaders.CORRELATION_ID, correlationId);
 	}
 
+	public MessageBuilder<T> setRequiresReply(Boolean requiresReply) {
+		return this.setHeader(MessageHeaders.REQUIRES_REPLY, requiresReply);
+	}
+
 	public MessageBuilder<T> setReplyChannel(MessageChannel replyChannel) {
 		return this.setHeader(MessageHeaders.REPLY_CHANNEL, replyChannel);
 	}

spring-integration-core/src/main/java/org/springframework/integration/handler/AbstractReplyProducingMessageHandler.java

@@ -109,6 +109,10 @@ public abstract class AbstractReplyProducingMessageHandler extends AbstractMessa
 				throw new MessageHandlingException(message, "handler '" + this
 						+ "' requires a reply, but no reply was received");
 			}
+			if (message != null && message.getHeaders().getRequiresReply()) {
+				throw new MessageHandlingException(message,
+						"A reply Message is required by this request Message, but none was received.");
+			}
 			if (logger.isDebugEnabled()) {
 				logger.debug("handler '" + this + "' produced no reply for request Message: " + message);
 			}

spring-integration-core/src/main/java/org/springframework/integration/handler/ArgumentArrayMessageMapper.java

@@ -236,6 +236,9 @@ public class ArgumentArrayMessageMapper implements InboundMessageMapper<Object[]
 			}
 			builder.copyHeaders(evaluatedHeaders);
 		}
+		if (!void.class.equals(this.method.getReturnType())) {
+			builder.setRequiresReply(true);
+		}
 		return builder.build();
 	}
 

spring-integration-core/src/test/java/org/springframework/integration/gateway/GatewayRequiresReplyTests-context.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans:beans xmlns="http://www.springframework.org/schema/integration"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+	xmlns:beans="http://www.springframework.org/schema/beans"
+	xsi:schemaLocation="http://www.springframework.org/schema/beans
+			http://www.springframework.org/schema/beans/spring-beans.xsd
+			http://www.springframework.org/schema/integration
+			http://www.springframework.org/schema/integration/spring-integration.xsd">
+
+	<gateway id="gateway"
+			 default-request-channel="requestChannel"
+			 default-reply-timeout="3000"
+			 service-interface="org.springframework.integration.gateway.GatewayRequiresReplyTests$TestService" />
+
+	<service-activator input-channel="requestChannel" expression="payload == 'foo' ? 'bar' : null"/>
+
+</beans:beans>

spring-integration-core/src/test/java/org/springframework/integration/gateway/GatewayRequiresReplyTests.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2002-2010 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.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.integration.gateway;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.integration.MessageHandlingException;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+
+/**
+ * @author Mark Fisher
+ * @since 2.0
+ */
+@ContextConfiguration
+@RunWith(SpringJUnit4ClassRunner.class)
+public class GatewayRequiresReplyTests {
+
+	@Autowired
+	private ApplicationContext applicationContext;
+
+
+	@Test
+	public void replyReceived() {
+		TestService gateway = (TestService) applicationContext.getBean("gateway");
+		String result = gateway.test("foo");
+		assertEquals("bar", result);
+	}
+
+	@Test(expected = MessageHandlingException.class)
+	public void noReplyReceived() {
+		TestService gateway = (TestService) applicationContext.getBean("gateway");
+		gateway.test("bad");
+	}
+
+
+	public static interface TestService {
+		public String test(String s);
+	}
+
+}