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 2000-2003 (C) Exoffice Technologies Inc. All Rights Reserved.
42 *
43 * $Id: MessageId.java,v 1.8 2003/08/07 13:33:01 tanderson Exp $
44 *
45 * Date Author Changes
46 * 02/26/2000 jimm Created
47 */
48
49
50 package org.exolab.jms.message;
51
52 import java.io.Externalizable;
53 import java.io.IOException;
54 import java.io.ObjectInput;
55 import java.io.ObjectOutput;
56
57 import javax.jms.JMSException;
58
59 import org.exolab.jms.Identifiable;
60 import org.exolab.jms.util.UUID;
61
62
63 /***
64 * The MessageId is a serializable object that uniquely identifies a message
65 *
66 * @version $Revision: 1.8 $ $Date: 2003/08/07 13:33:01 $
67 * @author <a href="mailto:jima@exoffice.com">Jim Alateras</a>
68 */
69 final public class MessageId
70 implements Externalizable, Identifiable {
71
72 /***
73 * Version Id used for streaming
74 */
75 static final long serialVersionUID = 2;
76
77 /***
78 * The JMS message identifier
79 */
80 private String _id = null;
81
82 /***
83 * The JMS message identifier prefix
84 */
85 public final static String PREFIX = "ID:";
86
87 /***
88 * A null object identity
89 */
90 private static final String NULL_ID = "ID:0";
91
92
93 /***
94 * Constructor provided for serialization
95 */
96 public MessageId() {
97 }
98
99 /***
100 * Construct a new <code>MessageId</code>
101 *
102 * @param id - the message identity
103 */
104 public MessageId(String id) {
105 _id = id;
106 }
107
108
109 public String getId() {
110 return _id;
111 }
112
113
114 public int hashCode() {
115 return _id.hashCode();
116 }
117
118
119 public void writeExternal(ObjectOutput out) throws IOException {
120 out.writeLong(serialVersionUID);
121 out.writeUTF(_id);
122 }
123
124
125 public void readExternal(ObjectInput in)
126 throws IOException, ClassNotFoundException {
127
128
129
130 long version = in.readLong();
131 if (version == serialVersionUID) {
132 _id = in.readUTF();
133 } else if (version == 1) {
134
135 long oldID = in.readLong();
136 String id = (String) in.readObject();
137 _id = PREFIX + id;
138 } else {
139 throw new IOException("Incorrect version enountered: " +
140 version + " This version = " +
141 serialVersionUID);
142 }
143 }
144
145
146 public String toString() {
147 return _id;
148 }
149
150
151 public boolean equals(Object object) {
152 boolean equal = (object == this);
153 if (!equal) {
154 if (object instanceof MessageId &&
155 ((MessageId) object)._id.equals(_id)) {
156 equal = true;
157 }
158 }
159
160 return equal;
161 }
162
163 /***
164 * Allocate a new globally unique message identifier
165 *
166 * @return a globally unique message identifier
167 */
168 public static String create() {
169 return UUID.next(PREFIX);
170 }
171
172 /***
173 * Return the 'null' JMSMessageID.
174 * This is the first Id recognised by OpenJMS, but not assigned
175 * to messages.
176 *
177 * @return String the 'null' message Id
178 */
179 public static String getNull() {
180 return NULL_ID;
181 }
182
183 }
184