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: DSPersistence.java,v 1.6 2005/01/11 13:51:37 ian Exp $
12   *
13   */
14  package gate.util.persistence;
15  
16  import gate.DataStore;
17  import gate.Factory;
18  import gate.creole.ResourceInstantiationException;
19  import gate.persist.PersistenceException;
20  
21  public class DSPersistence implements Persistence{
22  
23  
24    /**
25     * Populates this Persistence with the data that needs to be stored from the
26     * original source object.
27     */
28    public void extractDataFromSource(Object source)throws PersistenceException{
29      //check input
30      if(! (source instanceof DataStore)){
31        throw new UnsupportedOperationException(
32                  getClass().getName() + " can only be used for " +
33                  DataStore.class.getName() +
34                  " objects!\n" + source.getClass().getName() +
35                  " is not a " + DataStore.class.getName());
36      }
37  
38      DataStore ds = (DataStore)source;
39      className = ds.getClass().getName();
40      storageUrlString = ds.getStorageUrl();
41    }
42  
43    /**
44     * Creates a new object from the data contained. This new object is supposed
45     * to be a copy for the original object used as source for data extraction.
46     */
47    public Object createObject()throws PersistenceException,
48                                       ResourceInstantiationException{
49      return Factory.openDataStore(className, storageUrlString);
50    }
51  
52    protected String className;
53    protected String storageUrlString;
54    static final long serialVersionUID = 5952924943977701708L;
55  }
56