From 3cb0b360caba5b14a6aebca9a8e2463c988d9411 Mon Sep 17 00:00:00 2001
From: Mark Fisher <markfisher@vmware.com>
Date: Tue, 9 Mar 2010 20:59:36 +0000
Subject: [PATCH] INT-975 CorrelatingMessageHandler now implements the
 MessageProducer interface.

---
 .../aggregator/CorrelatingMessageHandler.java      | 14 +++++++++-----
 .../integration/handler/MessageHandlerChain.java   |  3 +--
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/org.springframework.integration/src/main/java/org/springframework/integration/aggregator/CorrelatingMessageHandler.java b/org.springframework.integration/src/main/java/org/springframework/integration/aggregator/CorrelatingMessageHandler.java
index 63eb5936b9..35da7a8f0b 100644
--- a/org.springframework.integration/src/main/java/org/springframework/integration/aggregator/CorrelatingMessageHandler.java
+++ b/org.springframework.integration/src/main/java/org/springframework/integration/aggregator/CorrelatingMessageHandler.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * 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.
@@ -28,6 +28,7 @@ import org.springframework.integration.context.IntegrationContextUtils;
 import org.springframework.integration.core.Message;
 import org.springframework.integration.core.MessageChannel;
 import org.springframework.integration.core.MessageHeaders;
+import org.springframework.integration.core.MessageProducer;
 import org.springframework.integration.handler.AbstractMessageHandler;
 import org.springframework.integration.message.MessageBuilder;
 import org.springframework.integration.store.MessageStore;
@@ -45,16 +46,19 @@ import java.util.concurrent.locks.ReentrantLock;
  * groups of messages that can be completed in batches. It is useful for aggregating, resequencing, or custom
  * implementations requiring correlation.
  * <p/>
- * To customize this handler inject {@link org.springframework.integration.aggregator.CorrelationStrategy}, {@link
- * org.springframework.integration.aggregator.CompletionStrategy} and {@link org.springframework.integration.aggregator.MessageGroupProcessor}
- * implementations as you require.
+ * To customize this handler inject {@link org.springframework.integration.aggregator.CorrelationStrategy},
+ * {@link org.springframework.integration.aggregator.CompletionStrategy}, and
+ * {@link org.springframework.integration.aggregator.MessageGroupProcessor} implementations as you require.
  * <p/>
  * By default the CorrelationStrategy will be a HeaderAttributeCorrelationStrategy and the CompletionStrategy will be a
  * SequenceSizeCompletionStrategy.
  *
  * @author Iwein Fuld
+ * @since 2.0
  */
-public class CorrelatingMessageHandler extends AbstractMessageHandler implements Lifecycle, BeanFactoryAware {
+public class CorrelatingMessageHandler extends AbstractMessageHandler
+		implements MessageProducer, Lifecycle, BeanFactoryAware {
+
     private static final Log logger = LogFactory.getLog(CorrelatingMessageHandler.class);
 
     public static final String COMPONENT_TYPE_LABEL = "aggregator";
diff --git a/org.springframework.integration/src/main/java/org/springframework/integration/handler/MessageHandlerChain.java b/org.springframework.integration/src/main/java/org/springframework/integration/handler/MessageHandlerChain.java
index 4c8b5be27c..9d68eed546 100644
--- a/org.springframework.integration/src/main/java/org/springframework/integration/handler/MessageHandlerChain.java
+++ b/org.springframework.integration/src/main/java/org/springframework/integration/handler/MessageHandlerChain.java
@@ -133,9 +133,8 @@ public class MessageHandlerChain implements MessageHandler, MessageProducer, Ord
 	private void configureChain() {
 		List<MessageHandler> handlers = this.handlers;
 		for (int i = 0; i < handlers.size(); i++) {
-			boolean last = (i == handlers.size() - 1);
 			MessageHandler handler = handlers.get(i);
-			if (!last) {
+			if (i < handlers.size() - 1) { // not the last handler
 				Assert.isTrue(handler instanceof MessageProducer, "All handlers except for " +
 						"the last one in the chain must implement the MessageProducer interface.");
 				final MessageHandler nextHandler = handlers.get(i + 1);