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1   /*
2    * Copyright 2004 Charles Blaxland
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package mnemosyne.archiver;
17  
18  import org.apache.commons.logging.Log;
19  import org.apache.commons.logging.LogFactory;
20  
21  import java.io.ObjectInputStream;
22  import java.io.InputStream;
23  import java.io.IOException;
24  
25  import mnemosyne.core.PersistentObject;
26  
27  /***
28   * @version $Id: ArchiveInputStream.java,v 1.1.1.1 2004/08/07 06:40:49 charlesblaxland Exp $
29   */
30  public class ArchiveInputStream extends ObjectInputStream
31  {
32      private static final Log log = LogFactory.getLog(ArchiveInputStream.class);
33  
34      public ArchiveInputStream(InputStream in)
35              throws IOException
36      {
37          super(in);
38          enableResolveObject(true);
39      }
40  
41      protected Object resolveObject(Object obj) throws IOException
42      {
43          if (obj instanceof PersistentObject)
44          {
45              PersistentObject persistentObject = (PersistentObject) obj;
46              obj = persistentObject.findTargetObject();
47              if (log.isTraceEnabled())
48              {
49                  log.trace("Resolved object " + persistentObject + " to instance of type " + obj);
50              }
51          }
52          return obj;
53      }
54  }