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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.apache.myfaces.orchestra.conversation;
20  
21  import java.io.Serializable;
22  
23  /**
24   * Provide information about the current conversation.
25   * <p>
26   * An instance of this type is stored in a thread-local variable to indicate
27   * what the "current conversation state" is. The getConversation() method
28   * can therefore be used to determine what conversation is currently active,
29   * and getBeanName() can be used to determine what the most recently-invoked
30   * conversation-scoped-bean was. This thread-local variable is maintained
31   * via the CurrentConversationAdvice which wraps every conversation-scoped 
32   * bean and intercepts all method calls to the bean.  
33   * <p>
34   * This object also records the fact that a specific bean is within a
35   * specific conversation. This data is saved during serialization so
36   * that on deserialize we know which conversation to reattach which
37   * bean to./
38   */
39  public class CurrentConversationInfo implements Serializable
40  {
41      private final String conversationName;
42      private final String beanName;
43  
44      /**
45       * The conversation object itself is not serializable (it is a Spring proxy
46       * object with various AOP advices attached to it). Therefore this reference
47       * must be transient. After deserialisation, this member is of course null,
48       * but is recalculated on demand in the getConversation method.
49       * <p>
50       * The beans that are <i>in</i> the conversation are hopefully serializable;
51       * they are saved directly and then reattached to the new Conversation instance.
52       */
53      private transient Conversation conversation;
54  
55      public CurrentConversationInfo(Conversation conversation, String beanName)
56      {
57          this.conversation = conversation;
58          this.conversationName = conversation.getName();
59          this.beanName = beanName;
60      }
61  
62      /**
63       * The conversation the bean is associated with.
64       */
65      public Conversation getConversation()
66      {
67          if(conversation == null)
68          {
69              ConversationManager conversationManager = ConversationManager.getInstance();
70              conversation = conversationManager.getConversation(conversationName);
71          }
72          return conversation;
73      }
74  
75      /**
76       * The bean name.
77       */
78      public String getBeanName()
79      {
80          return beanName;
81      }
82  }