Make ConversationManagers easier to subclass

Increased visibility of the following package scope classes:
- ContainedConversation
- ConversationContainer
- JdkConcurrentConversationLock
- NoOpConversationLock

Provided additional hook methods and accessors for subclasses.

Issue: SWF-756

spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/ContainedConversation.java

@@ -33,7 +33,7 @@ import org.springframework.webflow.core.collection.SharedAttributeMap;
  * 
  * @author Erwin Vervaet
  */
-class ContainedConversation implements Conversation, Serializable {
+public class ContainedConversation implements Conversation, Serializable {
 
 	private static final Log logger = LogFactory.getLog(SessionBindingConversationManager.class);
 
@@ -58,8 +58,16 @@ class ContainedConversation implements Conversation, Serializable {
 		this.attributes = new HashMap<Object, Object>();
 	}
 
+	protected void setContainer(ConversationContainer container) {
+		this.container = container;
+	}
+
 	public ConversationId getId() {
-		return id;
+		return this.id;
+	}
+
+	protected void setId(ConversationId id) {
+		this.id = id;
 	}
 
 	public void lock() {

spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/ConversationContainer.java

@@ -35,7 +35,7 @@ import org.springframework.webflow.conversation.NoSuchConversationException;
  * 
  * @author Erwin Vervaet
  */
-class ConversationContainer implements Serializable {
+public class ConversationContainer implements Serializable {
 
 	private static final Log logger = LogFactory.getLog(ConversationContainer.class);
 
@@ -91,7 +91,7 @@ class ConversationContainer implements Serializable {
 	 * @return the created conversation
 	 */
 	public synchronized Conversation createConversation(ConversationParameters parameters, ConversationLock lock) {
-		ContainedConversation conversation = new ContainedConversation(this, nextId(), lock);
+		ContainedConversation conversation = createContainedConversation(nextId(), lock);
 		conversation.putAttribute("name", parameters.getName());
 		conversation.putAttribute("caption", parameters.getCaption());
 		conversation.putAttribute("description", parameters.getDescription());
@@ -126,6 +126,10 @@ class ConversationContainer implements Serializable {
 		throw new NoSuchConversationException(id);
 	}
 
+	protected final List<ContainedConversation> getConversations() {
+		return conversations;
+	}
+
 	/**
 	 * Remove identified conversation from this container.
 	 */
@@ -145,4 +149,10 @@ class ConversationContainer implements Serializable {
 	private boolean maxExceeded() {
 		return maxConversations > 0 && conversations.size() > maxConversations;
 	}
+
+	// Hook methods
+
+	protected ContainedConversation createContainedConversation(ConversationId id, ConversationLock lock) {
+		return new ContainedConversation(this, id, lock);
+	}
 }

spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/JdkConcurrentConversationLock.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2008 the original author or authors.
+ * Copyright 2004-2012 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 +27,7 @@ import org.springframework.webflow.conversation.ConversationLockException;
  * 
  * @author Keith Donald
  */
-class JdkConcurrentConversationLock implements ConversationLock {
+public class JdkConcurrentConversationLock implements ConversationLock {
 
 	private Lock lock = new ReentrantLock();
 

spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/NoOpConversationLock.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2008 the original author or authors.
+ * Copyright 2004-2012 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.
@@ -23,7 +23,7 @@ import java.io.ObjectStreamException;
  * 
  * @author Keith Donald
  */
-class NoOpConversationLock implements ConversationLock {
+public class NoOpConversationLock implements ConversationLock {
 
 	/**
 	 * The singleton instance.

spring-webflow/src/main/java/org/springframework/webflow/conversation/impl/SessionBindingConversationManager.java

@@ -131,13 +131,11 @@ public class SessionBindingConversationManager implements ConversationManager {
 		return new ConversationContainer(maxConversations, sessionKey);
 	}
 
-	// internal helpers
-
 	/**
 	 * Obtain the conversation container from the session. Create a new empty container and add it to the session if no
 	 * existing container can be found.
 	 */
-	private ConversationContainer getConversationContainer() {
+	protected final ConversationContainer getConversationContainer() {
 		SharedAttributeMap<Object> sessionMap = ExternalContextHolder.getExternalContext().getSessionMap();
 		synchronized (sessionMap.getMutex()) {
 			ConversationContainer container = (ConversationContainer) sessionMap.get(sessionKey);