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My first initial commit with all of mine experimental changes.

Dmitry Kabak (userdima committed 13 years ago

Commit d37b88d1 parent 3f5b46618352 files · +2598093 −-8690Browse files

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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 javax.sql.rowset.spi;
27+
28+import javax.sql.*;
29+
30+/**
31+ * The synchronization mechanism that provides reader/writer capabilities for
32+ * disconnected <code>RowSet</code> objects.
33+ * A <code>SyncProvider</code> implementation is a class that extends the
34+ * <code>SyncProvider</code> abstract class.
35+ * <P>
36+ * A <code>SyncProvider</code> implementation is
37+ * identified by a unique ID, which is its fully qualified class name.
38+ * This name must be registered with the
39+ * <code>SyncFactory</code> SPI, thus making the implementation available to
40+ * all <code>RowSet</code> implementations.
41+ * The factory mechanism in the reference implementation uses this name to instantiate
42+ * the implementation, which can then provide a <code>RowSet</code> object with its
43+ * reader (a <code>javax.sql.RowSetReader</code> object) and its writer (a
44+ * <code>javax.sql.RowSetWriter</code> object).
45+ * <P>
46+ * The Jdbc <code>RowSet</code> Implementations specification provides two
47+ * reference implementations of the <code>SyncProvider</code> abstract class:
48+ * <code>RIOptimisticProvider</code> and <code>RIXMLProvider</code>.
49+ * The <code>RIOptimisticProvider</code> can set any <code>RowSet</code>
50+ * implementation with a <code>RowSetReader</code> object and a
51+ * <code>RowSetWriter</code> object. However, only the <code>RIXMLProvider</code>
52+ * implementation can set an <code>XmlReader</code> object and an
53+ * <code>XmlWriter</code> object. A <code>WebRowSet</code> object uses the
54+ * <code>XmlReader</code> object to read data in XML format to populate itself with that
55+ * data. It uses the <code>XmlWriter</code> object to write itself to a stream or
56+ * <code>java.io.Writer</code> object in XML format.
57+ * <P>
58+ * <h3>1.0 Naming Convention for Implementations</h3>
59+ * As a guide to naming <code>SyncProvider</code>
60+ * implementations, the following should be noted:
61+ * <UL>
62+ * <li>The name for a <code>SyncProvider</code> implementation
63+ * is its fully qualified class name.
64+ * <li>It is recommended that vendors supply a
65+ * <code>SyncProvider</code> implementation in a package named <code>providers</code>.
66+ * </UL>
67+ * <p>
68+ * For instance, if a vendor named Fred, Inc. offered a
69+ * <code>SyncProvider</code> implementation, you could have the following:
70+ * <PRE>
71+ * Vendor name: Fred, Inc.
72+ * Domain name of vendor: com.fred
73+ * Package name: com.fred.providers
74+ * SyncProvider implementation class name: HighAvailabilityProvider
75+ *
76+ * Fully qualified class name of SyncProvider implementation:
77+ * com.fred.providers.HighAvailabilityProvider
78+ * </PRE>
79+ * <P>
80+ * The following line of code uses the fully qualified name to register
81+ * this implementation with the <code>SyncFactory</code> static instance.
82+ * <PRE>
83+ * SyncFactory.registerProvider(
84+ * "com.fred.providers.HighAvailabilityProvider");
85+ * </PRE>
86+ * <P>
87+ * The default <code>SyncProvider</code> object provided with the reference
88+ * implementation uses the following name:
89+ * <pre>
90+ * com.sun.rowset.providers.RIOptimisticProvider
91+ * </pre>
92+ * <p>
93+ * A vendor can register a <code>SyncProvider</code> implementation class name
94+ * with Oracle Corporation by sending email to jdbc@sun.com.
95+ * Oracle will maintain a database listing the
96+ * available <code>SyncProvider</code> implementations for use with compliant
97+ * <code>RowSet</code> implementations. This database will be similar to the
98+ * one already maintained to list available JDBC drivers.
99+ * <P>
100+ * Vendors should refer to the reference implementation synchronization
101+ * providers for additional guidance on how to implement a new
102+ * <code>SyncProvider</code> implementation.
103+ *
104+ * <h3>2.0 How a <code>RowSet</code> Object Gets Its Provider</h3>
105+ *
106+ * A disconnected <code>Rowset</code> object may get access to a
107+ * <code>SyncProvider</code> object in one of the following two ways:
108+ * <UL>
109+ * <LI>Using a constructor<BR>
110+ * <PRE>
111+ * CachedRowSet crs = new CachedRowSet(
112+ * "com.fred.providers.HighAvailabilitySyncProvider");
113+ * </PRE>
114+ * <LI>Using the <code>setSyncProvider</code> method
115+ * <PRE>
116+ * CachedRowSet crs = new CachedRowSet();
117+ * crs.setSyncProvider("com.fred.providers.HighAvailabilitySyncProvider");
118+ * </PRE>
119+
120+ * </UL>
121+ * <p>
122+ * By default, the reference implementations of the <code>RowSet</code> synchronization
123+ * providers are always available to the Java platform.
124+ * If no other pluggable synchronization providers have been correctly
125+ * registered, the <code>SyncFactory</code> will automatically generate
126+ * an instance of the default <code>SyncProvider</code> reference implementation.
127+ * Thus, in the preceding code fragment, if no implementation named
128+ * <code>com.fred.providers.HighAvailabilitySyncProvider</code> has been
129+ * registered with the <code>SyncFactory</code> instance, <i>crs</i> will be
130+ * assigned the default provider in the reference implementation, which is
131+ * <code>com.sun.rowset.providers.RIOptimisticProvider</code>.
132+ * <p>
133+ * <h3>3.0 Violations and Synchronization Issues</h3>
134+ * If an update between a disconnected <code>RowSet</code> object
135+ * and a data source violates
136+ * the original query or the underlying data source constraints, this will
137+ * result in undefined behavior for all disconnected <code>RowSet</code> implementations
138+ * and their designated <code>SyncProvider</code> implementations.
139+ * Not defining the behavior when such violations occur offers greater flexibility
140+ * for a <code>SyncProvider</code>
141+ * implementation to determine its own best course of action.
142+ * <p>
143+ * A <code>SyncProvider</code> implementation
144+ * may choose to implement a specific handler to
145+ * handle a subset of query violations.
146+ * However if an original query violation or a more general data source constraint
147+ * violation is not handled by the <code>SyncProvider</code> implementation,
148+ * all <code>SyncProvider</code>
149+ * objects must throw a <code>SyncProviderException</code>.
150+ * <p>
151+ * <h3>4.0 Updatable SQL VIEWs</h3>
152+ * It is possible for any disconnected or connected <code>RowSet</code> object to be populated
153+ * from an SQL query that is formulated originally from an SQL <code>VIEW</code>.
154+ * While in many cases it is possible for an update to be performed to an
155+ * underlying view, such an update requires additional metadata, which may vary.
156+ * The <code>SyncProvider</code> class provides two constants to indicate whether
157+ * an implementation supports updating an SQL <code>VIEW</code>.
158+ * <ul>
159+ * <li><code><b>NONUPDATABLE_VIEW_SYNC</b></code> - Indicates that a <code>SyncProvider</code>
160+ * implementation does not support synchronization with an SQL <code>VIEW</code> as the
161+ * underlying source of data for the <code>RowSet</code> object.
162+ * <li><code><b>UPDATABLE_VIEW_SYNC</b></code> - Indicates that a
163+ * <code>SyncProvider</code> implementation
164+ * supports synchronization with an SQL <code>VIEW</code> as the underlying source
165+ * of data.
166+ * </ul>
167+ * <P>
168+ * The default is for a <code>RowSet</code> object not to be updatable if it was
169+ * populated with data from an SQL <code>VIEW</code>.
170+ * <P>
171+ * <h3>5.0 <code>SyncProvider</code> Constants</h3>
172+ * The <code>SyncProvider</code> class provides three sets of constants that
173+ * are used as return values or parameters for <code>SyncProvider</code> methods.
174+ * <code>SyncProvider</code> objects may be implemented to perform synchronization
175+ * between a <code>RowSet</code> object and its underlying data source with varying
176+ * degrees of of care. The first group of constants indicate how synchronization
177+ * is handled. For example, <code>GRADE_NONE</code> indicates that a
178+ * <code>SyncProvider</code> object will not take any care to see what data is
179+ * valid and will simply write the <code>RowSet</code> data to the data source.
180+ * <code>GRADE_MODIFIED_AT_COMMIT</code> indicates that the provider will check
181+ * only modified data for validity. Other grades check all data for validity
182+ * or set locks when data is modified or loaded.
183+ * <OL>
184+ * <LI>Constants to indicate the synchronization grade of a
185+ * <code>SyncProvider</code> object
186+ * <UL>
187+ * <LI>SyncProvider.GRADE_NONE
188+ * <LI>SyncProvider.GRADE_MODIFIED_AT_COMMIT
189+ * <LI>SyncProvider.GRADE_CHECK_ALL_AT_COMMIT
190+ * <LI>SyncProvider.GRADE_LOCK_WHEN_MODIFIED
191+ * <LI>SyncProvider.GRADE_LOCK_WHEN_LOADED
192+ * </UL>
193+ * <LI>Constants to indicate what locks are set on the data source
194+ * <UL>
195+ * <LI>SyncProvider.DATASOURCE_NO_LOCK
196+ * <LI>SyncProvider.DATASOURCE_ROW_LOCK
197+ * <LI>SyncProvider.DATASOURCE_TABLE_LOCK
198+ * <LI>SyncProvider.DATASOURCE_DB_LOCK
199+ * </UL>
200+ * <LI>Constants to indicate whether a <code>SyncProvider</code> object can
201+ * perform updates to an SQL <code>VIEW</code> <BR>
202+ * These constants are explained in the preceding section (4.0).
203+ * <UL>
204+ * <LI>SyncProvider.UPDATABLE_VIEW_SYNC
205+ * <LI>SyncProvider.NONUPDATABLE_VIEW_SYNC
206+ * </UL>
207+ * </OL>
208+ *
209+ * @author Jonathan Bruce
210+ * @see javax.sql.rowset.spi.SyncFactory
211+ * @see javax.sql.rowset.spi.SyncFactoryException
212+ */
213+public abstract class SyncProvider {
214+
215+ /**
216+ * Creates a default <code>SyncProvider</code> object.
217+ */
218+ public SyncProvider() {
219+ }
220+
221+ /**
222+ * Returns the unique identifier for this <code>SyncProvider</code> object.
223+ *
224+ * @return a <code>String</code> object with the fully qualified class name of
225+ * this <code>SyncProvider</code> object
226+ */
227+ public abstract String getProviderID();
228+
229+ /**
230+ * Returns a <code>javax.sql.RowSetReader</code> object, which can be used to
231+ * populate a <code>RowSet</code> object with data.
232+ *
233+ * @return a <code>javax.sql.RowSetReader</code> object
234+ */
235+ public abstract RowSetReader getRowSetReader();
236+
237+ /**
238+ * Returns a <code>javax.sql.RowSetWriter</code> object, which can be
239+ * used to write a <code>RowSet</code> object's data back to the
240+ * underlying data source.
241+ *
242+ * @return a <code>javax.sql.RowSetWriter</code> object
243+ */
244+ public abstract RowSetWriter getRowSetWriter();
245+
246+ /**
247+ * Returns a constant indicating the
248+ * grade of synchronization a <code>RowSet</code> object can expect from
249+ * this <code>SyncProvider</code> object.
250+ *
251+ * @return an int that is one of the following constants:
252+ * SyncProvider.GRADE_NONE,
253+ * SyncProvider.GRADE_CHECK_MODIFIED_AT_COMMIT,
254+ * SyncProvider.GRADE_CHECK_ALL_AT_COMMIT,
255+ * SyncProvider.GRADE_LOCK_WHEN_MODIFIED,
256+ * SyncProvider.GRADE_LOCK_WHEN_LOADED
257+ */
258+ public abstract int getProviderGrade();
259+
260+
261+ /**
262+ * Sets a lock on the underlying data source at the level indicated by
263+ * <i>datasource_lock</i>. This should cause the
264+ * <code>SyncProvider</code> to adjust its behavior by increasing or
265+ * decreasing the level of optimism it provides for a successful
266+ * synchronization.
267+ *
268+ * @param datasource_lock one of the following constants indicating the severity
269+ * level of data source lock required:
270+ * <pre>
271+ * SyncProvider.DATASOURCE_NO_LOCK,
272+ * SyncProvider.DATASOURCE_ROW_LOCK,
273+ * SyncProvider.DATASOURCE_TABLE_LOCK,
274+ * SyncProvider.DATASOURCE_DB_LOCK,
275+ * </pre>
276+ * @throws SyncProviderException if an unsupported data source locking level
277+ * is set.
278+ * @see #getDataSourceLock
279+ */
280+ public abstract void setDataSourceLock(int datasource_lock)
281+ throws SyncProviderException;
282+
283+ /**
284+ * Returns the current data source lock severity level active in this
285+ * <code>SyncProvider</code> implementation.
286+ *
287+ * @return a constant indicating the current level of data source lock
288+ * active in this <code>SyncProvider</code> object;
289+ * one of the following:
290+ * <pre>
291+ * SyncProvider.DATASOURCE_NO_LOCK,
292+ * SyncProvider.DATASOURCE_ROW_LOCK,
293+ * SyncProvider.DATASOURCE_TABLE_LOCK,
294+ * SyncProvider.DATASOURCE_DB_LOCK
295+ * </pre>
296+ * @throws SyncProviderExceptiom if an error occurs determining the data
297+ * source locking level.
298+ * @see #setDataSourceLock
299+
300+ */
301+ public abstract int getDataSourceLock()
302+ throws SyncProviderException;
303+
304+ /**
305+ * Returns whether this <code>SyncProvider</code> implementation
306+ * can perform synchronization between a <code>RowSet</code> object
307+ * and the SQL <code>VIEW</code> in the data source from which
308+ * the <code>RowSet</code> object got its data.
309+ *
310+ * @return an <code>int</code> saying whether this <code>SyncProvider</code>
311+ * object supports updating an SQL <code>VIEW</code>; one of the
312+ * following:
313+ * SyncProvider.UPDATABLE_VIEW_SYNC,
314+ * SyncProvider.NONUPDATABLE_VIEW_SYNC
315+ */
316+ public abstract int supportsUpdatableView();
317+
318+ /**
319+ * Returns the release version of this <code>SyncProvider</code> instance.
320+ *
321+ * @return a <code>String</code> detailing the release version of the
322+ * <code>SyncProvider</code> implementation
323+ */
324+ public abstract String getVersion();
325+
326+ /**
327+ * Returns the vendor name of this <code>SyncProvider</code> instance
328+ *
329+ * @return a <code>String</code> detailing the vendor name of this
330+ * <code>SyncProvider</code> implementation
331+ */
332+ public abstract String getVendor();
333+
334+ /*
335+ * Standard description of synchronization grades that a SyncProvider
336+ * could provide.
337+ */
338+
339+ /**
340+ * Indicates that no synchronization with the originating data source is
341+ * provided. A <code>SyncProvider</code>
342+ * implementation returning this grade will simply attempt to write
343+ * updates in the <code>RowSet</code> object to the underlying data
344+ * source without checking the validity of any data.
345+ *
346+ */
347+ public static final int GRADE_NONE = 1;
348+
349+ /**
350+ * Indicates a low level optimistic synchronization grade with
351+ * respect to the originating data source.
352+ *
353+ * A <code>SyncProvider</code> implementation
354+ * returning this grade will check only rows that have changed.
355+ *
356+ */
357+ public static final int GRADE_CHECK_MODIFIED_AT_COMMIT = 2;
358+
359+ /**
360+ * Indicates a high level optimistic synchronization grade with
361+ * respect to the originating data source.
362+ *
363+ * A <code>SyncProvider</code> implementation
364+ * returning this grade will check all rows, including rows that have not
365+ * changed.
366+ */
367+ public static final int GRADE_CHECK_ALL_AT_COMMIT = 3;
368+
369+ /**
370+ * Indicates a pessimistic synchronization grade with
371+ * respect to the originating data source.
372+ *
373+ * A <code>SyncProvider</code>
374+ * implementation returning this grade will lock the row in the originating
375+ * data source.
376+ */
377+ public static final int GRADE_LOCK_WHEN_MODIFIED = 4;
378+
379+ /**
380+ * Indicates the most pessimistic synchronization grade with
381+ * respect to the originating
382+ * data source. A <code>SyncProvider</code>
383+ * implementation returning this grade will lock the entire view and/or
384+ * table affected by the original statement used to populate a
385+ * <code>RowSet</code> object.
386+ */
387+ public static final int GRADE_LOCK_WHEN_LOADED = 5;
388+
389+ /**
390+ * Indicates that no locks remain on the originating data source. This is the default
391+ * lock setting for all <code>SyncProvider</code> implementations unless
392+ * otherwise directed by a <code>RowSet</code> object.
393+ */
394+ public static final int DATASOURCE_NO_LOCK = 1;
395+
396+ /**
397+ * Indicates that a lock is placed on the rows that are touched by the original
398+ * SQL statement used to populate the <code>RowSet</code> object
399+ * that is using this <code>SyncProvider</code> object.
400+ */
401+ public static final int DATASOURCE_ROW_LOCK = 2;
402+
403+ /**
404+ * Indicates that a lock is placed on all tables that are touched by the original
405+ * SQL statement used to populate the <code>RowSet</code> object
406+ * that is using this <code>SyncProvider</code> object.
407+ */
408+ public static final int DATASOURCE_TABLE_LOCK = 3;
409+
410+ /**
411+ * Indicates that a lock is placed on the entire data source that is the source of
412+ * data for the <code>RowSet</code> object
413+ * that is using this <code>SyncProvider</code> object.
414+ */
415+ public static final int DATASOURCE_DB_LOCK = 4;
416+
417+ /**
418+ * Indicates that a <code>SyncProvider</code> implementation
419+ * supports synchronization between a <code>RowSet</code> object and
420+ * the SQL <code>VIEW</code> used to populate it.
421+ */
422+ public static final int UPDATABLE_VIEW_SYNC = 5;
423+
424+ /**
425+ * Indicates that a <code>SyncProvider</code> implementation
426+ * does <B>not</B> support synchronization between a <code>RowSet</code>
427+ * object and the SQL <code>VIEW</code> used to populate it.
428+ */
429+ public static final int NONUPDATABLE_VIEW_SYNC = 6;
430+}