Added CompositeMessage and added the 'nextTarget' header to MessageHeaders (and the corresponding methods in MessageBuilder).

org.springframework.integration/src/main/java/org/springframework/integration/message/CompositeMessage.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2002-2008 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.message;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.List;
+
+
+/**
+ * @author Mark Fisher
+ */
+public class CompositeMessage extends GenericMessage<List<Message<?>>> implements Iterable<Message<?>> {
+
+	public CompositeMessage(Message<?>[] messages) {
+		this(Arrays.asList(messages));
+	}
+
+	public CompositeMessage(List<Message<?>> messages) {
+		super(Collections.unmodifiableList(messages));
+	}
+
+
+	public Iterator<Message<?>> iterator() {
+		return this.getPayload().iterator();
+	}
+
+}

org.springframework.integration/src/main/java/org/springframework/integration/message/MessageBuilder.java

@@ -111,7 +111,19 @@ public final class MessageBuilder<T> {
 		return this.setHeader(MessageHeaders.CORRELATION_ID, correlationId);
 	}
 
-	public MessageBuilder<T> setReturnAddress(Object returnAddress) {
+	public MessageBuilder<T> setNextTarget(MessageTarget nextTarget) {
+		return this.setHeader(MessageHeaders.NEXT_TARGET, nextTarget);
+	}
+
+	public MessageBuilder<T> setNextTarget(String nextTarget) {
+		return this.setHeader(MessageHeaders.NEXT_TARGET, nextTarget);
+	}
+
+	public MessageBuilder<T> setReturnAddress(MessageTarget returnAddress) {
+		return this.setHeader(MessageHeaders.RETURN_ADDRESS, returnAddress);
+	}
+
+	public MessageBuilder<T> setReturnAddress(String returnAddress) {
 		return this.setHeader(MessageHeaders.RETURN_ADDRESS, returnAddress);
 	}
 

org.springframework.integration/src/main/java/org/springframework/integration/message/MessageHeaders.java

@@ -36,6 +36,8 @@ public final class MessageHeaders implements Map<String, Object>, Serializable {
 
 	public static final String CORRELATION_ID = "internal.header.correlationId";
 
+	public static final String NEXT_TARGET = "internal.header.nextTarget";
+
 	public static final String RETURN_ADDRESS = "internal.header.returnAddress";
 
 	public static final String EXPIRATION_DATE = "internal.header.exprirationDate";
@@ -72,6 +74,10 @@ public final class MessageHeaders implements Map<String, Object>, Serializable {
 		return this.get(RETURN_ADDRESS);
 	}
 
+	public Object getNextTarget() {
+		return this.get(NEXT_TARGET);
+	}
+
 	public Integer getSequenceNumber() {
 		Integer sequenceNumber = this.get(SEQUENCE_NUMBER, Integer.class);
 		return (sequenceNumber != null ? sequenceNumber : 0);