View Javadoc

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 2002-2003 (C) Exoffice Technologies Inc. All Rights Reserved.
42   *
43   *
44   * $Id: BaseTransactionLogEntry.java,v 1.1 2004/11/26 01:51:01 tanderson Exp $
45   *
46   * Date			Author  Changes
47   * 20/11/2001   jima    Created
48   */
49  package org.exolab.jms.tranlog;
50  
51  import java.io.Externalizable;
52  import java.io.IOException;
53  import java.io.ObjectInput;
54  import java.io.ObjectOutput;
55  
56  
57  /***
58   * This is the base entry that is streamed into the transaction log file.
59   * All other transaction log entry classes must extend this class.
60   * <p>
61   * Each entry has the associated XID and the created time stamp, along with
62   * the identity of the resource that created the entry
63   */
64  public abstract class BaseTransactionLogEntry implements Externalizable {
65  
66      /***
67       * This is the unique id used to identify the version of the class
68       * for the purpose of Serialization
69       */
70      static final long serialVersionUID = 2;
71  
72      /***
73       * This is the transaction identity that this entry belongs too
74       */
75      private ExternalXid _externalXid = null;
76  
77      /***
78       * This is the resource identity that this entry belongs too
79       */
80      private String _resourceId;
81  
82      /***
83       * This is a time stamp when the entry was created
84       */
85      private long _created = -1;
86  
87      /***
88       * This is the time that the transaction expires in ms. It is initialized
89       * to zero, which means that it never expired
90       */
91      private long _expiryTime = 0;
92  
93  
94      /***
95       * Default constructor for serialization
96       */
97      BaseTransactionLogEntry() {
98      }
99  
100     /***
101      * Instantiate an instance of  this class with a transaction identifier
102      * resource identifier and created date
103      *
104      * @param txid - the transaction identifier
105      * @param rid - the resource identifier
106      * @param created - timestamp for this entry
107      */
108     BaseTransactionLogEntry(ExternalXid txid, String rid, long created) {
109         _externalXid = txid;
110         _resourceId = rid;
111         _created = created;
112     }
113 
114     /***
115      * Create a new instance populating it with the state of the specified
116      * object
117      *
118      * @param copy - object to copy
119      */
120     BaseTransactionLogEntry(BaseTransactionLogEntry copy) {
121         _externalXid = new ExternalXid(copy._externalXid);
122         _resourceId = copy._resourceId;
123         _created = copy._created;
124         _expiryTime = copy._expiryTime;
125     }
126 
127     /***
128      * Set the transaction identifier
129      *
130      * @param txid - the transaction identifier
131      */
132     public void setExternalXid(ExternalXid txid) {
133         _externalXid = txid;
134     }
135 
136     /***
137      * Get the transaction identifier
138      *
139      * @return ExternalXid
140      */
141     public ExternalXid getExternalXid() {
142         return _externalXid;
143     }
144 
145     /***
146      * Set the resource identity for the entry
147      *
148      * @param rid - the resource identity
149      */
150     public void setResourceId(String rid) {
151         _resourceId = rid;
152     }
153 
154     /***
155      * Get the resource identifier
156      *
157      * @return the resource identifier
158      */
159     public String getResourceId() {
160         return _resourceId;
161     }
162 
163     /***
164      * Set the time in ms that this record was created
165      *
166      * @param time - time in ms
167      */
168     public void setCreated(long time) {
169         _created = time;
170     }
171 
172     /***
173      * Set the created time of this entry to now
174      */
175     public void setCreated() {
176         _created = System.currentTimeMillis();
177     }
178 
179     /***
180      * Return the time that this entry was created
181      *
182      * @return long
183      */
184     public long getCreated() {
185         return _created;
186     }
187 
188 
189     /***
190      * Set the expiry time for this transaction, which is an absolute time in
191      * milliseconds.
192      *
193      * @param long - absolute expiry time
194      */
195     public void setExpiryTime(long time) {
196         _expiryTime = time;
197     }
198 
199     /***
200      * Retrieve the expiry time of this transaction
201      *
202      * @return long
203      */
204     public long getExpiryTime() {
205         return _expiryTime;
206     }
207 
208     /***
209      * Check whether the trnasaction has expired
210      *
211      * @return boolean - true if it has expired; false otherwise
212      */
213     public boolean transactionExpired() {
214         return System.currentTimeMillis() > _expiryTime;
215     }
216 
217     // implementation of Externalizable.writeExternal
218     public void writeExternal(ObjectOutput stream)
219         throws IOException {
220         if (isValid()) {
221             stream.writeLong(serialVersionUID);
222             stream.writeObject(_externalXid);
223             stream.writeUTF(_resourceId);
224             stream.writeLong(_created);
225         } else {
226             throw new IOException("writeExternal : entry has invalid state");
227         }
228     }
229 
230     // implementation of Externalizable.writeExternal
231     public void readExternal(ObjectInput stream)
232         throws IOException, ClassNotFoundException {
233         long version = stream.readLong();
234         if (version == serialVersionUID) {
235             _externalXid = (ExternalXid) stream.readObject();
236             _resourceId = stream.readUTF();
237             _created = stream.readLong();
238             if (!isValid()) {
239                 throw new IOException("readExternal : entry has invalid state");
240             }
241         } else {
242             throw new IOException("No support for BaseTransactionLogEntry " +
243                 "with version " + version);
244         }
245     }
246 
247     /***
248      * Verify that this record has a valid state, which is denoted by
249      * _externalXid , resourceId and _created being not equal to -1.
250      *
251      * @return boolean - true if the entry is valid
252      */
253     boolean isValid() {
254         return ((_externalXid != null) &&
255             (_resourceId != null) &&
256             (_created != -1));
257     }
258 
259 }
260