1   /*
2    *  Copyright (c) 1998-2005, The University of Sheffield.
3    *
4    *  This file is part of GATE (see http://gate.ac.uk/), and is free
5    *  software, licenced under the GNU Library General Public License,
6    *  Version 2, June 1991 (in the distribution as file licence.html,
7    *  and also available at http://gate.ac.uk/gate/licence.html).
8    *
9    *  Valentin Tablan 26/10/2001
10   *
11   *  $Id: CorpusPersistence.java,v 1.5 2005/01/11 13:51:37 ian Exp $
12   *
13   */
14  
15  package gate.util.persistence;
16  
17  
18  import java.util.ArrayList;
19  import java.util.Iterator;
20  
21  import gate.Corpus;
22  import gate.creole.ResourceInstantiationException;
23  import gate.persist.PersistenceException;
24  
25  
26  public class CorpusPersistence extends LRPersistence {
27    /**
28     * Populates this Persistence with the data that needs to be stored from the
29     * original source object.
30     */
31    public void extractDataFromSource(Object source)throws PersistenceException{
32      //check input
33      if(! (source instanceof Corpus)){
34        throw new UnsupportedOperationException(
35                  getClass().getName() + " can only be used for " +
36                  Corpus.class.getName() +
37                  " objects!\n" + source.getClass().getName() +
38                  " is not a " + Corpus.class.getName());
39      }
40  
41      Corpus corpus = (Corpus)source;
42      super.extractDataFromSource(source);
43      if(dsData == null){
44        //transient corpus; we still need to save the docs
45        docList = new ArrayList();
46        Iterator docIter = corpus.iterator();
47        while(docIter.hasNext()){
48          docList.add(PersistenceManager.
49                      getPersistentRepresentation(docIter.next()));
50        }
51      }else{
52        //persistent corpus; it takes care of documents by itself
53        //nothing to do :)
54        docList = null;
55      }
56    }
57  
58  
59    /**
60     * Creates a new object from the data contained. This new object is supposed
61     * to be a copy for the original object used as source for data extraction.
62     */
63    public Object createObject()throws PersistenceException,
64                                       ResourceInstantiationException{
65      Corpus corpus = (Corpus)super.createObject();
66      if(docList != null){
67        //transient corpus; we need to recreate the docs
68        if(!docList.isEmpty() && corpus.isEmpty()){
69          Iterator docIter = docList.iterator();
70          while(docIter.hasNext()){
71            corpus.add(PersistenceManager.
72                       getTransientRepresentation(docIter.next()));
73          }
74  
75        }
76      }
77      return corpus;
78    }
79  
80  
81    protected ArrayList docList;
82    static final long serialVersionUID = 6181534551802883626L;
83  }