INT-3846: SimpleMessageStore Improvements

JIRAs:
https://jira.spring.io/browse/INT-3830
https://jira.spring.io/browse/INT-3523
https://jira.spring.io/browse/INT-3846

* Fix the OOM condition, when we `release()` `UpperBound` independently of the previous `remove` result (https://jira.spring.io/browse/INT-3846)
* Fix "confuse" around `groupCapacity`, when we really didn't care about individual groups (https://jira.spring.io/browse/INT-3523)
* Add `upperBoundTimeout` to have a hook to wait some time for the empty slot in the store (https://jira.spring.io/browse/INT-3830)
* Fix some JavaDocs warnings
* Fix some typos

* Fix inconsistency in the `DelayHandler` around `removeMessageFromGroup` when `MS` is `SimpleMessageStore`
 * Remove `UpperBound.release()` operation from `SimpleMessageStore.removeGroup()`.
 The waiting process should worry about the new `UpperBound` instance.

Some other polishing

`tryAcquire` outside of the `lock`

Move `tryAcquire` within the `addMessageToGroup` outside of `lock`.
But do that only for groups which already exist.
For the new groups we have a fresh `UpperBound`, so no need to worry about dead lock and
 we can obtain  a permit immediately.

SimpleMessageGroup: BlockingQueue -> LinkedHashSet

`SimpleMessageStore`: use "unsynchonized" `SimpleMessageGroup`

Make some synchronization fixes according to the migration to the `LinkedHashSet`

Avoid extra `Collection`

`ResequencingMessageHandler`: compare `size()` of collections instead of `containsAll()`

Fix `ConcurrentModificationException` in the `AbstractKeyValueMessageStore`

Add `SimpleMessageStore.clearMessageGroup()`

Accept polishing and fix `RedisChannelMessageStoreTests`

`@Deprecated` `MessageGroupStore.removeMessageFromGroup()`

Fix some typos

Introduce `SimpleMessageGroupFactory`

Extract `MessageGroupFactory` and address PR comments

Polishing after rebase

JavaDocs and Reference Manual

Fix JavaDocs

spring-integration-redis/src/main/java/org/springframework/integration/redis/store/RedisChannelMessageStore.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 the original author or authors.
+ * Copyright 2014-2016 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.
@@ -13,6 +13,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.integration.redis.store;
 
 import java.util.List;
@@ -27,7 +28,8 @@ import org.springframework.data.redis.serializer.RedisSerializer;
 import org.springframework.data.redis.serializer.StringRedisSerializer;
 import org.springframework.integration.store.ChannelMessageStore;
 import org.springframework.integration.store.MessageGroup;
-import org.springframework.integration.store.SimpleMessageGroup;
+import org.springframework.integration.store.MessageGroupFactory;
+import org.springframework.integration.store.SimpleMessageGroupFactory;
 import org.springframework.jmx.export.annotation.ManagedAttribute;
 import org.springframework.messaging.Message;
 import org.springframework.util.Assert;
@@ -38,6 +40,7 @@ import org.springframework.util.Assert;
  * Requires {@link #setBeanName(String)} which is used as part of the key.
  *
  * @author Gary Russell
+ * @author Artem Bilan
  * @since 4.0
  *
  */
@@ -45,6 +48,8 @@ public class RedisChannelMessageStore implements ChannelMessageStore, BeanNameAw
 
 	private final RedisTemplate<Object, Message<?>> redisTemplate;
 
+	private volatile MessageGroupFactory messageGroupFactory = new SimpleMessageGroupFactory();
+
 	private String beanName;
 
 	/**
@@ -71,6 +76,22 @@ public class RedisChannelMessageStore implements ChannelMessageStore, BeanNameAw
 		this.redisTemplate.setValueSerializer(valueSerializer);
 	}
 
+	/**
+	 * Specify the {@link MessageGroupFactory} to create {@link MessageGroup} object where
+	 * it is necessary.
+	 * Defaults to {@link SimpleMessageGroupFactory}.
+	 * @param messageGroupFactory the {@link MessageGroupFactory} to use.
+	 * @since 4.3
+	 */
+	public void setMessageGroupFactory(MessageGroupFactory messageGroupFactory) {
+		Assert.notNull(messageGroupFactory, "'messageGroupFactory' must not be null");
+		this.messageGroupFactory = messageGroupFactory;
+	}
+
+	protected MessageGroupFactory getMessageGroupFactory() {
+		return this.messageGroupFactory;
+	}
+
 	@Override
 	public void setBeanName(String name) {
 		Assert.notNull(name, "'beanName' must not be null");
@@ -78,11 +99,11 @@ public class RedisChannelMessageStore implements ChannelMessageStore, BeanNameAw
 	}
 
 	protected String getBeanName() {
-		return beanName;
+		return this.beanName;
 	}
 
 	protected RedisTemplate<Object, Message<?>> getRedisTemplate() {
-		return redisTemplate;
+		return this.redisTemplate;
 	}
 
 	@Override
@@ -99,7 +120,7 @@ public class RedisChannelMessageStore implements ChannelMessageStore, BeanNameAw
 	@Override
 	public MessageGroup getMessageGroup(Object groupId) {
 		List<Message<?>> messages = this.redisTemplate.boundListOps(groupId).range(0, -1);
-		return new SimpleMessageGroup(messages, groupId);
+		return getMessageGroupFactory().create(messages, groupId);
 	}
 
 	@Override

spring-integration-redis/src/main/java/org/springframework/integration/redis/store/RedisChannelPriorityMessageStore.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014 the original author or authors.
+ * Copyright 2014-2016 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.
@@ -27,7 +27,6 @@ import org.springframework.data.redis.connection.RedisConnectionFactory;
 import org.springframework.integration.IntegrationMessageHeaderAccessor;
 import org.springframework.integration.store.MessageGroup;
 import org.springframework.integration.store.PriorityCapableChannelMessageStore;
-import org.springframework.integration.store.SimpleMessageGroup;
 import org.springframework.jmx.export.annotation.ManagedAttribute;
 import org.springframework.messaging.Message;
 import org.springframework.util.Assert;
@@ -41,10 +40,12 @@ import org.springframework.util.Assert;
  * Requires that groupId is a String.
  *
  * @author Gary Russell
+ * @author Artem Bilan
  * @since 4.0
  *
  */
-public class RedisChannelPriorityMessageStore extends RedisChannelMessageStore implements PriorityCapableChannelMessageStore {
+public class RedisChannelPriorityMessageStore extends RedisChannelMessageStore
+		implements PriorityCapableChannelMessageStore {
 
 	private final Comparator<String> keysComparator = new Comparator<String>() {
 
@@ -85,7 +86,7 @@ public class RedisChannelPriorityMessageStore extends RedisChannelMessageStore i
 			List<Message<?>> messages = this.getRedisTemplate().boundListOps(key).range(0, -1);
 			allMessages.addAll(messages);
 		}
-		return new SimpleMessageGroup(allMessages, groupId);
+		return getMessageGroupFactory().create(allMessages, groupId);
 	}