VersionedDataObject


1   /*
2    * Copyright (c) 2003 - 2007 OpenSubsystems s.r.o. Slovak Republic. All rights reserved.
3    * 
4    * Project: OpenSubsystems
5    * 
6    * $Id: VersionedDataObject.java,v 1.2 2007/01/07 06:15:40 bastafidli Exp $
7    * 
8    * This program is free software; you can redistribute it and/or modify
9    * it under the terms of the GNU General Public License as published by
10   * the Free Software Foundation; version 2 of the License. 
11   * 
12   * This program is distributed in the hope that it will be useful,
13   * but WITHOUT ANY WARRANTY; without even the implied warranty of
14   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15   * GNU General Public License for more details.
16   * 
17   * You should have received a copy of the GNU General Public License
18   * along with this program; if not, write to the Free Software
19   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
20   */
21   
22  package org.opensubsystems.patterns.versioneddata.data;
23  
24  import java.sql.Timestamp  ;
25  
26  import org.opensubsystems.core.data.DataObject;
27  import org.opensubsystems.core.data.ModifiableDataObject;
28  import org.opensubsystems.core.util.HashCodeUtils;
29  
30  /**
31   * Base class for all data objects, which can be versioned and therefore has to
32   * track the current version, if they are tip and the base version of, which this
33   * is a new version.
34   * 
35   * @version $Id: VersionedDataObject.java,v 1.2 2007/01/07 06:15:40 bastafidli Exp $
36   * @author Peter Satury
37   * @code.reviewer Miro Halas
38   * @code.reviewed Initial revision
39   */
40  public abstract class VersionedDataObject extends ModifiableDataObject
41  {
42     // Constants ////////////////////////////////////////////////////////////////
43  
44     /**
45      * This is the first version number for any versionable data object.
46      */
47     public static final int FIRST_VERSION_NUMBER = 1;
48     
49     // Attributes ///////////////////////////////////////////////////////////////
50  
51     /**
52      * Id of the data object, which is base version of this data object. If this 
53      * data object is the base version (it is the first version) then this is 
54      * equal to the id.
55      */
56     protected int m_iBaseVersionId; 
57  
58     /**
59      * Flag if this data object is the latest (newest) version called tip.
60      */
61     protected boolean m_bTip;
62     
63     /**
64      * Data object version number. This is the actual version number of this data
65      * object.
66      */
67     protected int m_iVersion;
68     
69     // Constructors /////////////////////////////////////////////////////////////
70     
71     /**
72      * Default constructor.
73      */
74     public VersionedDataObject(
75     )
76     {
77        this(DataObject.NEW_ID);
78     }
79  
80     /**
81      * Simple constructor creating new data object in particular domain.
82      * 
83      * @param iDomainId - domain this data object belongs to
84      */
85     public VersionedDataObject(
86        int iDomainId
87     )
88     {
89        this(DataObject.NEW_ID, iDomainId, DataObject.NEW_ID, true, 
90             FIRST_VERSION_NUMBER, null, null);
91     }
92  
93     /**
94      * Full constructor.
95      * 
96      * @param iId - id of this data object
97      * @param iDomainId - domain this data object belongs to
98      * @param iBaseVersionId - data object base version ID
99      * @param bTip - flag if this data object is TIP
100     * @param iVersion - version number of this data object
101     * @param creationTimestamp - timestamp when the data object was created.
102     * @param modificationTimestamp - timestamp when the data object was last 
103     *                                time modified.
104     */
105    public VersionedDataObject(
106       int       iId,
107       int       iDomainId,
108       int       iBaseVersionId,
109       boolean   bTip,
110       int       iVersion,
111       Timestamp   creationTimestamp, 
112       Timestamp   modificationTimestamp
113    )
114    {
115       super(iId, iDomainId, creationTimestamp, modificationTimestamp);
116       
117       m_iBaseVersionId = iBaseVersionId;
118       m_bTip = bTip;
119       m_iVersion = iVersion;
120    }
121    
122    // Accessors ////////////////////////////////////////////////////////////////
123 
124    /**
125     * Get id of the data object, which is base version of this data object.
126     * 
127     * @return int
128     */
129    public int getBaseVersionId()
130    {
131       return m_iBaseVersionId;
132    }
133 
134    /**
135     * Set id of the data object, which is base version of this data object.
136     * 
137     * @param baseVersionId - id of the version on which is this object based on 
138     */
139    public void setBaseVersionId(
140       int baseVersionId
141    )
142    {
143       m_iBaseVersionId = baseVersionId;
144    }
145    
146    /**
147     * Get flag if this data object is the latest (newest) version called tip.
148     * 
149     * @return boolean - true if this is the latest version 
150     */
151    public boolean isTip()
152    {
153       return m_bTip;
154    }
155 
156    /**
157     * Set flag if this data object is the latest (newest) version called tip.
158     * 
159     * @param tip - true if this is the tip - latest (newest) version
160     */
161    public void setTip(
162       boolean tip
163    )
164    {
165       m_bTip = tip;
166    }
167 
168    /**
169     * Get the actual version number of this data object.
170     * 
171     * @return int
172     */
173    public int getVersion()
174    {
175       return m_iVersion;
176    }
177    
178    /**
179     * Set the actual version number of this data object.
180     * 
181     * @param version - version of this object
182     */
183    public void setVersion(
184       int version
185    )
186    {
187       m_iVersion = version;
188    }
189 
190    /**
191     * {@inheritDoc}
192     */
193    public boolean equals(
194       Object   oObject
195    )
196    {
197       boolean bReturn = false;
198       VersionedDataObject helper;
199 
200       if (oObject == this)
201       {
202          bReturn = true;
203       }
204       else if ((oObject != null) && (oObject instanceof VersionedDataObject))
205       {
206          helper = (VersionedDataObject) oObject;
207          bReturn = (m_bTip == helper.m_bTip)
208                    && (m_iBaseVersionId == helper.m_iBaseVersionId)
209                    && (m_iVersion == helper.m_iVersion)
210                    && (super.equals(oObject));
211       }
212       
213       return bReturn;
214    }
215 
216    /**
217     * {@inheritDoc}
218     */
219    public int hashCode()
220    {
221       int iResult = HashCodeUtils.SEED;
222       iResult = HashCodeUtils.hash(iResult, m_bTip);
223       iResult = HashCodeUtils.hash(iResult, m_iBaseVersionId);
224       iResult = HashCodeUtils.hash(iResult, m_iVersion);
225       iResult = HashCodeUtils.hash(iResult, super.hashCode());
226       return iResult;
227    }
228 
229    // Helper methods ///////////////////////////////////////////////////////////
230    
231    /**
232     * Restore all values from specified values. This is here to reinitialize
233     * object in case it needs to be reused or reconstructed (e.g. when rollback
234     * is issued).
235     * 
236     * @param iId - id of this data object
237     * @param iDomainId - domain this data object belongs to
238     * @param iBaseVersionId - data object base version ID
239     * @param bTip - flag if this data object is TIP
240     * @param iVersion - version number of this data object
241     * @param creationTimestamp - timestamp when the data object was created.
242     * @param modificationTimestamp - timestamp when the data object was last 
243     *                                time modified.
244     */
245    protected void restore(
246       int       iId,
247       int       iDomainId,
248       int       iBaseVersionId,
249       boolean   bTip,
250       int       iVersion,
251       Timestamp   creationTimestamp, 
252       Timestamp   modificationTimestamp
253    )
254    {
255       super.restore(iId, iDomainId, creationTimestamp, modificationTimestamp);
256       
257       m_iBaseVersionId = iBaseVersionId;
258       m_bTip = bTip;
259       m_iVersion = iVersion;
260    }
261 }
262
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