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Java > Open Source Codes > sync4j > server > tools > IdSpaceGenerator


1 /**
2  * Copyright (C) 2003-2005 Funambol
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17  */
18
19 package sync4j.server.tools;
20
21 import sync4j.framework.protocol.IdGenerator;
22 import sync4j.framework.server.ID;
23 import sync4j.framework.server.store.*;
24
25 import sync4j.server.config.Configuration;
26
27 /**
28  * This class works as a simple id generator that read his value from the datastore
29  *
30  * @version $Id: IdSpaceGenerator.java,v 1.1 2005/07/25 15:28:37 nichele Exp $
31  */
32 public class IdSpaceGenerator
33 implements IdGenerator, java.io.Serializable JavaDoc {
34
35     // -------------------------------------------------------------- Properties
36 private ID id = null;
37
38     // ------------------------------------------------------------ Constructors
39
40     /**
41      * Creates a new instance of IdSpaceGenerator
42      *
43      * @param idSpace the id space
44      */
45     public IdSpaceGenerator(String JavaDoc idSpace) {
46         id = new ID(idSpace);
47     }
48
49
50     /**
51      * Reset the generator to 0.
52      */
53     public void reset() {
54         id.setValue(0);
55         try {
56             Configuration.getConfiguration().getStore().store(id);
57         } catch (PersistentStoreException ex) {
58             throw new IllegalStateException JavaDoc("Error resetting the counter '" + id.getIdSpace() + "': " + ex.getMessage());
59         }
60     }
61
62     /**
63      * Returns the next value of the counter
64      *
65      * @return the next generated value
66      */
67     public synchronized String JavaDoc next() {
68         try {
69             Configuration.getConfiguration().getStore().read(id);
70         } catch (PersistentStoreException ex) {
71             throw new IllegalStateException JavaDoc("Error reading the counter '" + id.getIdSpace() + "': " + ex.getMessage());
72         }
73         return String.valueOf(id.getValue());
74     }
75
76     /**
77      * Returns the last generated id (which is the current id).
78      *
79      * @return the last generated id
80      */
81     public synchronized String JavaDoc current() {
82         return String.valueOf(id.getValue());
83     }
84 }
85
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