INT-958: add convenient parameterless callback for expiring message groups.

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

@@ -81,7 +81,7 @@ public class CorrelatingMessageHandler extends AbstractMessageHandler implements
 		Assert.notNull(store);
 		Assert.notNull(processor);
 		this.messageStore = store;
-		store.registerExpiryCallback(new MessageGroupCallback() {
+		store.registerMessageGroupExpiryCallback(new MessageGroupCallback() {
 			public void execute(MessageGroup group) {
 				forceComplete(group);
 			}

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

@@ -41,17 +41,17 @@ public abstract class AbstractMessageGroupStore implements MessageGroupStore, It
 
 	/**
 	 * Convenient injection point for expiry callbacks in the message store. Each of the callbacks provided will simply
-	 * be registered with the store using {@link #registerExpiryCallback(MessageGroupCallback)}.
+	 * be registered with the store using {@link #registerMessageGroupExpiryCallback(MessageGroupCallback)}.
 	 * 
 	 * @param expiryCallbacks the expiry callbacks to add
 	 */
 	public void setExpiryCallbacks(Collection<MessageGroupCallback> expiryCallbacks) {
 		for (MessageGroupCallback callback : expiryCallbacks) {
-			registerExpiryCallback(callback);
+			registerMessageGroupExpiryCallback(callback);
 		}
 	}
 
-	public void registerExpiryCallback(MessageGroupCallback callback) {
+	public void registerMessageGroupExpiryCallback(MessageGroupCallback callback) {
 		expiryCallbacks.add(callback);
 	}
 

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

@@ -63,7 +63,7 @@ public interface MessageGroupStore {
 	 * 
 	 * @param callback a callback to execute when a message group is cleaned up
 	 */
-	void registerExpiryCallback(MessageGroupCallback callback);
+	void registerMessageGroupExpiryCallback(MessageGroupCallback callback);
 
 	/**
 	 * Extract all expired groups (whose timestamp is older than the current time less the threshold provided) and call
@@ -74,7 +74,7 @@ public interface MessageGroupStore {
 	 * @param timeout the timeout threshold to use
 	 * @return the number of message groups expired
 	 * 
-	 * @see #registerExpiryCallback(MessageGroupCallback)
+	 * @see #registerMessageGroupExpiryCallback(MessageGroupCallback)
 	 */
 	int expireMessageGroups(long timeout);
 

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

@@ -0,0 +1,97 @@
+/*
+ * 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.store;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.springframework.beans.factory.DisposableBean;
+import org.springframework.beans.factory.InitializingBean;
+import org.springframework.context.ApplicationContext;
+import org.springframework.util.Assert;
+
+/**
+ * Convenient configurable component to allow explicit timed expiry of {@link MessageGroup} instances in a
+ * {@link MessageGroupStore}. This component provides a no-args {@link #run()} method that is useful for remote or
+ * timed execution and a {@link #destroy()} method that can optionally be called on shutdown.
+ * 
+ * @author Dave Syer
+ * 
+ */
+public class MessageGroupStoreReaper implements Runnable, DisposableBean, InitializingBean {
+
+	private static Log logger = LogFactory.getLog(MessageGroupStoreReaper.class);
+
+	private MessageGroupStore messageGroupStore;
+	private boolean expireOnDestroy = false;
+	private long timeout = -1;
+
+	public MessageGroupStoreReaper(MessageGroupStore messageGroupStore) {
+		this.messageGroupStore = messageGroupStore;
+	}
+
+	public MessageGroupStoreReaper() {
+	}
+
+	/**
+	 * Flag to indicate that the stores should be expired when this component is destroyed (i.e. usuually when its
+	 * enclosing {@link ApplicationContext} is closed).
+	 * 
+	 * @param expireOnDestroy the flag value to set
+	 */
+	public void setExpireOnDestroy(boolean expireOnDestroy) {
+		this.expireOnDestroy = expireOnDestroy;
+	}
+
+	/**
+	 * @param timeout the timeout to set
+	 */
+	public void setTimeout(long timeout) {
+		this.timeout = timeout;
+	}
+
+	/**
+	 * A message group store to expire according the the other configurations.
+	 * 
+	 * @param messageGroupStore the {@link MessageGroupStore} to set
+	 */
+	public void setMessageGroupStore(MessageGroupStore messageGroupStore) {
+		this.messageGroupStore = messageGroupStore;
+	}
+
+	public void afterPropertiesSet() throws Exception {
+		Assert.state(messageGroupStore != null, "A MessageGroupStore must be provided");
+	}
+
+	public void destroy() throws Exception {
+		if (expireOnDestroy) {
+			logger.info("Expiring all messages from message group store: " + messageGroupStore);
+			messageGroupStore.expireMessageGroups(0);
+		}
+	}
+
+	/**
+	 * Expire all message groups older than the {@link #setTimeout(long) timeout} provided. Normally this method would
+	 * be executed by a scheduled task.
+	 */
+	public void run() {
+		if (timeout >= 0) {
+			if (logger.isDebugEnabled()) {
+				logger.debug("Expiring all messages older than timeout=" + timeout + " from message group store: "
+						+ messageGroupStore);
+			}
+			messageGroupStore.expireMessageGroups(timeout);
+		}
+	}
+
+}