OPEN - issue INT-1063: MessageStore: correlation and grouping API

https://jira.springsource.org/browse/INT-1063

org.springframework.integration/src/main/java/org/springframework/integration/aggregator/CorrelatingMessageHandler.java

@@ -16,7 +16,7 @@
 
 package org.springframework.integration.aggregator;
 
-import java.util.List;
+import java.util.Collection;
 import java.util.Queue;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.ConcurrentHashMap;
@@ -30,7 +30,6 @@ import java.util.concurrent.locks.ReentrantLock;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
-
 import org.springframework.context.Lifecycle;
 import org.springframework.integration.channel.ChannelResolver;
 import org.springframework.integration.channel.MessageChannelTemplate;
@@ -293,11 +292,11 @@ public class CorrelatingMessageHandler extends AbstractMessageHandler implements
 	protected final boolean forceComplete(Object key) {
 		try {
 			if (tracker.tryLockFor(key)) {
-				List<Message<?>> all = store.list(key);
+				Collection<Message<?>> all = store.list(key);
 				MessageGroup group = new MessageGroup(all, completionStrategy, key, deleteOrTrackCallback());
 				if (all.size() > 0) {
 					// last chance for normal completion
-					MessageChannel outputChannel = resolveReplyChannel(all.get(0), this.outputChannel);
+					MessageChannel outputChannel = resolveReplyChannel(all.iterator().next(), this.outputChannel);
 					boolean processed = false;
 					if (group.isComplete()) {
 						outputProcessor.processAndSend(group, channelTemplate, outputChannel);

org.springframework.integration/src/main/java/org/springframework/integration/store/MessageStore.java

@@ -16,7 +16,7 @@
 
 package org.springframework.integration.store;
 
-import java.util.List;
+import java.util.Collection;
 import java.util.UUID;
 
 import org.springframework.integration.core.Message;
@@ -63,6 +63,6 @@ public interface MessageStore {
 	 * provided correlationId header value.
 	 * @see org.springframework.integration.core.MessageHeaders#getCorrelationId()
 	 */
-	List<Message<?>> list(Object correlationId);
+	Collection<Message<?>> list(Object correlationId);
 
 }

org.springframework.integration/src/main/java/org/springframework/integration/util/UUIDConverter.java

@@ -0,0 +1,111 @@
+/*
+ * 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.util;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectOutputStream;
+import java.io.UnsupportedEncodingException;
+import java.util.UUID;
+
+import org.springframework.core.convert.converter.Converter;
+import org.springframework.util.ClassUtils;
+
+/**
+ * Utility to help generate UUID instances from generic objects.
+ * 
+ * @author Dave Syer
+ *
+ */
+public class UUIDConverter implements Converter<Object, UUID> {
+
+	public static final String DEFAULT_CHARSET = "UTF-8";
+	private final String charset;
+	
+	public UUIDConverter() {
+		this(DEFAULT_CHARSET);
+	}
+	
+	public UUIDConverter(String charset) {
+		this.charset = charset;
+	}
+
+
+	public UUID convert(Object source) {
+		return getUUID(source, charset);
+	}
+
+	public static UUID getUUID(Object input) {
+		return getUUID(input, DEFAULT_CHARSET);
+	}
+	
+	public static UUID getUUID(Object input, String charset) {
+
+		if (input == null) {
+			return null;
+		}
+
+		if (input instanceof UUID) {
+			return (UUID) input;
+		}
+
+		if (input instanceof String) {
+			try {
+				return UUID.fromString((String) input);
+			}
+			catch (IllegalArgumentException e) {
+				try {
+					return UUID.nameUUIDFromBytes(((String) input).getBytes(charset));
+				}
+				catch (UnsupportedEncodingException ex) {
+					throw new IllegalStateException("Cannot convert String using charset=" + charset, ex);
+				}
+			}
+		}
+
+		if (ClassUtils.isPrimitiveOrWrapper(input.getClass())) {
+			try {
+				return UUID.nameUUIDFromBytes(input.toString().getBytes(charset));
+			}
+			catch (UnsupportedEncodingException e) {
+				throw new IllegalStateException("Cannot convert primitive using charset=" + charset, e);
+			}
+		}
+
+		byte[] bytes = serialize(input);
+		return UUID.nameUUIDFromBytes(bytes);
+
+	}
+
+	private static byte[] serialize(Object object) {
+
+		if (object == null) {
+			return null;
+		}
+
+		ByteArrayOutputStream stream = new ByteArrayOutputStream();
+		try {
+			new ObjectOutputStream(stream).writeObject(object);
+		}
+		catch (IOException e) {
+			throw new IllegalArgumentException("Could not serialize object of type: " + object.getClass(), e);
+		}
+
+		return stream.toByteArray();
+
+	}
+
+}