1 /*
2 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
3 *
4 * This software is open source.
5 * See the bottom of this file for the licence.
6 */
7
8 package org.dom4j.util;
9
10 /***
11 * <p>
12 * <code>SimpleSingleton</code> is an implementation of the SingletonStrategy
13 * interface used to provide common factory access for the same object instance.
14 * This implementation will create a new instance from the class specified and
15 * will not create a new one unless it is reset.
16 * </p>
17 *
18 * @author <a href="mailto:ddlucas@users.sourceforge.net">David Lucas </a>
19 * @version $Revision: 1.3 $
20 */
21
22 public class SimpleSingleton implements SingletonStrategy {
23 private String singletonClassName = null;
24
25 private Object singletonInstance = null;
26
27 public SimpleSingleton() {
28 }
29
30 public Object instance() {
31 return singletonInstance;
32 }
33
34 public void reset() {
35 if (singletonClassName != null) {
36 Class clazz = null;
37 try {
38 clazz = Thread.currentThread().getContextClassLoader().loadClass(
39 singletonClassName);
40 singletonInstance = clazz.newInstance();
41 } catch (Exception ignore) {
42 try {
43 clazz = Class.forName(singletonClassName);
44 singletonInstance = clazz.newInstance();
45 } catch (Exception ignore2) {
46 }
47 }
48
49 }
50 }
51
52 public void setSingletonClassName(String singletonClassName) {
53 this.singletonClassName = singletonClassName;
54 reset();
55 }
56
57 }
58
59 /*
60 * Redistribution and use of this software and associated documentation
61 * ("Software"), with or without modification, are permitted provided that the
62 * following conditions are met:
63 *
64 * 1. Redistributions of source code must retain copyright statements and
65 * notices. Redistributions must also contain a copy of this document.
66 *
67 * 2. Redistributions in binary form must reproduce the above copyright notice,
68 * this list of conditions and the following disclaimer in the documentation
69 * and/or other materials provided with the distribution.
70 *
71 * 3. The name "DOM4J" must not be used to endorse or promote products derived
72 * from this Software without prior written permission of MetaStuff, Ltd. For
73 * written permission, please contact dom4j-info@metastuff.com.
74 *
75 * 4. Products derived from this Software may not be called "DOM4J" nor may
76 * "DOM4J" appear in their names without prior written permission of MetaStuff,
77 * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
78 *
79 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
80 *
81 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
82 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
83 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
84 * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
85 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
86 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
87 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
88 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
89 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
90 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
91 * POSSIBILITY OF SUCH DAMAGE.
92 *
93 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
94 */