1 /***
2 * Redistribution and use of this software and associated documentation
3 * ("Software"), with or without modification, are permitted provided
4 * that the following conditions are met:
5 *
6 * 1. Redistributions of source code must retain copyright
7 * statements and notices. Redistributions must also contain a
8 * copy of this document.
9 *
10 * 2. Redistributions in binary form must reproduce the
11 * above copyright notice, this list of conditions and the
12 * following disclaimer in the documentation and/or other
13 * materials provided with the distribution.
14 *
15 * 3. The name "Exolab" must not be used to endorse or promote
16 * products derived from this Software without prior written
17 * permission of Exoffice Technologies. For written permission,
18 * please contact info@exolab.org.
19 *
20 * 4. Products derived from this Software may not be called "Exolab"
21 * nor may "Exolab" appear in their names without prior written
22 * permission of Exoffice Technologies. Exolab is a registered
23 * trademark of Exoffice Technologies.
24 *
25 * 5. Due credit should be given to the Exolab Project
26 * (http://www.exolab.org/).
27 *
28 * THIS SOFTWARE IS PROVIDED BY EXOFFICE TECHNOLOGIES AND CONTRIBUTORS
29 * ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT
30 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
31 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
32 * EXOFFICE TECHNOLOGIES OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
33 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
34 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
35 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
37 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
38 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
39 * OF THE POSSIBILITY OF SUCH DAMAGE.
40 *
41 * Copyright 2000-2005 (C) Exoffice Technologies Inc. All Rights Reserved.
42 */
43 package org.exolab.jms.persistence;
44
45 import java.sql.Connection;
46 import java.sql.PreparedStatement;
47 import java.sql.ResultSet;
48
49
50 /***
51 * This class generates seeds.
52 *
53 * @version $Revision: 1.4 $ $Date: 2005/08/31 05:45:50 $
54 * @author <a href="mailto:tma@netspace.net.au">Tim Anderson</a>
55 */
56 class SeedGenerator {
57
58 /***
59 * Return the next seed value for the given name.
60 *
61 * @param connection the connection to use
62 * @param name - the name of the seed
63 * @return long - the next seed value
64 * @exception PersistenceException - if the seed cannot be retrieved
65 */
66 public synchronized long next(Connection connection, String name)
67 throws PersistenceException {
68
69 PreparedStatement select = null;
70 PreparedStatement update = null;
71 PreparedStatement insert = null;
72 ResultSet result = null;
73 long value = 0;
74
75 try {
76 select = connection.prepareStatement(
77 "select seed from seeds where name=?");
78 select.setString(1, name);
79
80 result = select.executeQuery();
81 if (result.next()) {
82 value = result.getLong(1);
83 value++;
84 update = connection.prepareStatement(
85 "update seeds set seed=? where name=?");
86 update.setLong(1, value);
87 update.setString(2, name);
88 update.executeUpdate();
89 } else {
90 value = 1;
91 insert = connection.prepareStatement(
92 "insert into seeds (name, seed) values (?,?)");
93 insert.setString(1, name);
94 insert.setLong(2, value);
95 insert.executeUpdate();
96 }
97 } catch (Exception exception) {
98 throw new PersistenceException("Failed to generate seed="+ name,
99 exception);
100 } finally {
101 SQLHelper.close(result);
102 SQLHelper.close(select);
103 SQLHelper.close(update);
104 SQLHelper.close(insert);
105 }
106
107 return value;
108 }
109
110 /***
111 * Remove all seeds.
112 *
113 * @param connection the connection to use
114 * @exception PersistenceException if the seeds can't be removed
115 */
116 public void removeAll(Connection connection)
117 throws PersistenceException {
118
119 PreparedStatement delete = null;
120 try {
121 delete = connection.prepareStatement("delete from seeds");
122 delete.executeUpdate();
123 } catch (Exception error) {
124 throw new PersistenceException("Failed in removeAll with " +
125 error.toString());
126 } finally {
127 SQLHelper.close(delete);
128 }
129 }
130
131 }