1 /*
2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package com.sun.rowset.providers;
27
28 import com.sun.rowset.JdbcRowSetResourceBundle;
29 import javax.sql.*;
30 import java.io.*;
31
32 import javax.sql.rowset.spi.*;
33 import com.sun.rowset.internal.*;
34
35 /**
36 * The reference implementation of a JDBC Rowset synchronization provider
37 * providing optimistic synchronization with a relational datastore
38 * using any JDBC technology-enabled driver.
39 * <p>
40 * <h3>1.0 Backgroud</h3>
41 * This synchronization provider is registered with the
42 * <code>SyncFactory</code> by default as the
43 * <code>com.sun.rowset.providers.RIOptimisticProvider</code>.
44 * As an extension of the <code>SyncProvider</code> abstract
45 * class, it provides the reader and writer classes required by disconnected
46 * rowsets as <code>javax.sql.RowSetReader</code> and <code>javax.sql.RowSetWriter</code>
47 * interface implementations. As a reference implementation,
48 * <code>RIOptimisticProvider</code> provides a
49 * fully functional implementation offering a medium grade classification of
50 * syncrhonization, namely GRADE_CHECK_MODIFIED_AT_COMMIT. A
51 * disconnected <code>RowSet</code> implementation using the
52 * <code>RIOptimisticProvider</code> can expect the writer to
53 * check only rows that have been modified in the <code>RowSet</code> against
54 * the values in the data source. If there is a conflict, that is, if a value
55 * in the data source has been changed by another party, the
56 * <code>RIOptimisticProvider</code> will not write any of the changes to the data
57 * source and will throw a <code>SyncProviderException</code> object.
58 *
59 * <h3>2.0 Usage</h3>
60 * Standard disconnected <code>RowSet</code> implementations may opt to use this
61 * <code>SyncProvider</code> implementation in one of two ways:
62 * <OL>
63 * <LI>By specifically calling the <code>setSyncProvider</code> method
64 defined in the <code>CachedRowSet</code> interface
65 * <pre>
66 * CachedRowset crs = new FooCachedRowSetImpl();
67 * crs.setSyncProvider("com.sun.rowset.providers.RIOptimisticProvider");
68 * </pre>
69 * <LI>By specifying it in the constructor of the <code>RowSet</code>
70 * implementation
71 * <pre>
72 * CachedRowset crs = new FooCachedRowSetImpl(
73 * "com.sun.rowset.providers.RIOptimisticProvider");
74 * </pre>
75 * </OL>
76 * Note that because the <code>RIOptimisticProvider</code> implementation is
77 * the default provider, it will always be the provider when no provider ID is
78 * specified to the constructor.
79 * <P>
80 * See the standard <code>RowSet</code> reference implementations in the
81 * <code>com.sun.rowset</code> package for more details.
82 *
83 * @author Jonathan Bruce
84 * @see javax.sql.rowset.spi.SyncProvider
85 * @see javax.sql.rowset.spi.SyncProviderException
86 * @see javax.sql.rowset.spi.SyncFactory
87 * @see javax.sql.rowset.spi.SyncFactoryException
88 *
89 */
90 public final class RIOptimisticProvider extends SyncProvider implements Serializable {
91
92 private CachedRowSetReader reader;
93 private CachedRowSetWriter writer;
94
95 /**
96 * The unique provider identifier.
97 */
98 private String providerID = "com.sun.rowset.providers.RIOptimisticProvider";
99
100 /**
101 * The vendor name of this SyncProvider implementation
102 */
103 private String vendorName = "Oracle Corporation";
104
105 /**
106 * The version number of this SyncProvider implementation
107 */
108 private String versionNumber = "1.0";
109
110 /**
111 * ResourceBundle
112 */
113 private JdbcRowSetResourceBundle resBundle;
114
115 /**
116 * Creates an <code>RIOptimisticProvider</code> object initialized with the
117 * fully qualified class name of this <code>SyncProvider</code> implementation
118 * and a default reader and writer.
119 * <P>
120 * This provider is available to all disconnected <code>RowSet</code> implementations
121 * as the default persistence provider.
122 */
123 public RIOptimisticProvider() {
124 providerID = this.getClass().getName();
125 reader = new CachedRowSetReader();
126 writer = new CachedRowSetWriter();
127 try {
128 resBundle = JdbcRowSetResourceBundle.getJdbcRowSetResourceBundle();
129 } catch(IOException ioe) {
130 throw new RuntimeException(ioe);
131 }
132 }
133
134 /**
135 * Returns the <code>'javax.sql.rowset.providers.RIOptimisticProvider'</code>
136 * provider identification string.
137 *
138 * @return String Provider ID of this persistence provider
139 */
140 public String getProviderID() {
141 return providerID;
142 }
143
144 /**
145 * Returns the <code>javax.sql.RowSetWriter</code> object for this
146 * <code>RIOptimisticProvider</code> object. This is the writer that will
147 * write changes made to the <code>Rowset</code> object back to the data source.
148 *
149 * @return the <code>javax.sql.RowSetWriter</code> object for this
150 * <code>RIOptimisticProvider</code> object
151 */
152 public RowSetWriter getRowSetWriter() {
153 try {
154 writer.setReader(reader);
155 } catch (java.sql.SQLException e) {}
156 return writer;
157 }
158
159 /**
160 * Returns the <code>javax.sql.RowSetReader</code> object for this
161 * <code>RIOptimisticProvider</code> object. This is the reader that will
162 * populate a <code>RowSet</code> object using this <code>RIOptimisticProvider</code>.
163 *
164 * @return the <code>javax.sql.RowSetReader</code> object for this
165 * <code>RIOptimisticProvider</code> object
166 */
167 public RowSetReader getRowSetReader() {
168 return reader;
169 }
170
171 /**
172 * Returns the <code>SyncProvider</code> grade of synchronization that
173 * <code>RowSet</code> objects can expect when using this
174 * implementation. As an optimisic synchonization provider, the writer
175 * will only check rows that have been modified in the <code>RowSet</code>
176 * object.
177 */
178 public int getProviderGrade() {
179 return SyncProvider.GRADE_CHECK_MODIFIED_AT_COMMIT;
180 }
181
182 /**
183 * Modifies the data source lock severity according to the standard
184 * <code>SyncProvider</code> classifications.
185 *
186 * @param datasource_lock An <code>int</code> indicating the level of locking to be
187 * set; must be one of the following constants:
188 * <PRE>
189 * SyncProvider.DATASOURCE_NO_LOCK,
190 * SyncProvider.DATASOURCE_ROW_LOCK,
191 * SyncProvider.DATASOURCE_TABLE_LOCK,
192 * SyncProvider.DATASOURCE_DB_LOCk
193 * </PRE>
194 * @throws SyncProviderException if the parameter specified is not
195 * <code>SyncProvider.DATASOURCE_NO_LOCK</code>
196 */
197 public void setDataSourceLock(int datasource_lock) throws SyncProviderException {
198 if(datasource_lock != SyncProvider.DATASOURCE_NO_LOCK ) {
199 throw new SyncProviderException(resBundle.handleGetObject("riop.locking").toString());
200 }
201 }
202
203 /**
204 * Returns the active data source lock severity in this
205 * reference implementation of the <code>SyncProvider</code>
206 * abstract class.
207 *
208 * @return <code>SyncProvider.DATASOURCE_NO_LOCK</code>.
209 * The reference implementation does not support data source locks.
210 */
211 public int getDataSourceLock() throws SyncProviderException {
212 return SyncProvider.DATASOURCE_NO_LOCK;
213 }
214
215 /**
216 * Returns the supported updatable view abilities of the
217 * reference implementation of the <code>SyncProvider</code>
218 * abstract class.
219 *
220 * @return <code>SyncProvider.NONUPDATABLE_VIEW_SYNC</code>. The
221 * the reference implementation does not support updating tables
222 * that are the source of a view.
223 */
224 public int supportsUpdatableView() {
225 return SyncProvider.NONUPDATABLE_VIEW_SYNC;
226 }
227
228 /**
229 * Returns the release version ID of the Reference Implementation Optimistic
230 * Synchronization Provider.
231 *
232 * @return the <code>String</code> detailing the version number of this SyncProvider
233 */
234 public String getVersion() {
235 return this.versionNumber;
236 }
237
238 /**
239 * Returns the vendor name of the Reference Implementation Optimistic
240 * Synchronization Provider
241 *
242 * @return the <code>String</code> detailing the vendor name of this
243 * SyncProvider
244 */
245 public String getVendor() {
246 return this.vendorName;
247 }
248
249 private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {
250 // Default state initialization happens here
251 ois.defaultReadObject();
252 // Initialization of transient Res Bundle happens here .
253 try {
254 resBundle = JdbcRowSetResourceBundle.getJdbcRowSetResourceBundle();
255 } catch(IOException ioe) {
256 throw new RuntimeException(ioe);
257 }
258
259 }
260 static final long serialVersionUID =-3143367176751761936L;
261
262 }