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 2000-2004 (C) Exoffice Technologies Inc. All Rights Reserved.
42 *
43 * $Id: MessageId.java,v 1.1 2004/11/26 01:50:43 tanderson Exp $
44 */
45 package org.exolab.jms.message;
46
47 import java.io.Externalizable;
48 import java.io.IOException;
49 import java.io.ObjectInput;
50 import java.io.ObjectOutput;
51
52 import org.exolab.jms.common.uuid.UUID;
53
54
55 /***
56 * The MessageId is a serializable object that uniquely identifies a message
57 *
58 * @version $Revision: 1.1 $ $Date: 2004/11/26 01:50:43 $
59 * @author <a href="mailto:jima@comware.com.au">Jim Alateras</a>
60 */
61 final public class MessageId
62 implements Externalizable {
63
64 /***
65 * Version Id used for streaming
66 */
67 static final long serialVersionUID = 2;
68
69 /***
70 * The JMS message identifier
71 */
72 private String _id = null;
73
74 /***
75 * The JMS message identifier prefix
76 */
77 public final static String PREFIX = "ID:";
78
79 /***
80 * A null object identity
81 */
82 private static final String NULL_ID = "ID:0";
83
84
85 /***
86 * Constructor provided for serialization
87 */
88 public MessageId() {
89 }
90
91 /***
92 * Construct a new <code>MessageId</code>
93 *
94 * @param id - the message identity
95 */
96 public MessageId(String id) {
97 _id = id;
98 }
99
100 public String getId() {
101 return _id;
102 }
103
104
105 public int hashCode() {
106 return _id.hashCode();
107 }
108
109
110 public void writeExternal(ObjectOutput out) throws IOException {
111 out.writeLong(serialVersionUID);
112 out.writeUTF(_id);
113 }
114
115
116 public void readExternal(ObjectInput in)
117 throws IOException, ClassNotFoundException {
118
119
120
121 long version = in.readLong();
122 if (version == serialVersionUID) {
123 _id = in.readUTF();
124 } else if (version == 1) {
125
126 long oldID = in.readLong();
127 String id = (String) in.readObject();
128 _id = PREFIX + id;
129 } else {
130 throw new IOException("Incorrect version enountered: " +
131 version + " This version = " +
132 serialVersionUID);
133 }
134 }
135
136
137 public String toString() {
138 return _id;
139 }
140
141
142 public boolean equals(Object object) {
143 boolean equal = (object == this);
144 if (!equal) {
145 if (object instanceof MessageId &&
146 ((MessageId) object)._id.equals(_id)) {
147 equal = true;
148 }
149 }
150
151 return equal;
152 }
153
154 /***
155 * Allocate a new globally unique message identifier
156 *
157 * @return a globally unique message identifier
158 */
159 public static String create() {
160 return UUID.next(PREFIX);
161 }
162
163 /***
164 * Return the 'null' JMSMessageID.
165 * This is the first Id recognised by OpenJMS, but not assigned
166 * to messages.
167 *
168 * @return String the 'null' message Id
169 */
170 public static String getNull() {
171 return NULL_ID;
172 }
173
174 }
175