--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/sql/rowset/spi/SyncProvider.java Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,430 @@
+/*
+ * Copyright 2003-2004 Sun Microsystems, Inc. All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package javax.sql.rowset.spi;
+
+import javax.sql.*;
+
+/**
+ * The synchronization mechanism that provides reader/writer capabilities for
+ * disconnected <code>RowSet</code> objects.
+ * A <code>SyncProvider</code> implementation is a class that extends the
+ * <code>SyncProvider</code> abstract class.
+ * <P>
+ * A <code>SyncProvider</code> implementation is
+ * identified by a unique ID, which is its fully qualified class name.
+ * This name must be registered with the
+ * <code>SyncFactory</code> SPI, thus making the implementation available to
+ * all <code>RowSet</code> implementations.
+ * The factory mechanism in the reference implementation uses this name to instantiate
+ * the implementation, which can then provide a <code>RowSet</code> object with its
+ * reader (a <code>javax.sql.RowSetReader</code> object) and its writer (a
+ * <code>javax.sql.RowSetWriter</code> object).
+ * <P>
+ * The Jdbc <code>RowSet</code> Implementations specification provides two
+ * reference implementations of the <code>SyncProvider</code> abstract class:
+ * <code>RIOptimisticProvider</code> and <code>RIXMLProvider</code>.
+ * The <code>RIOptimisticProvider</code> can set any <code>RowSet</code>
+ * implementation with a <code>RowSetReader</code> object and a
+ * <code>RowSetWriter</code> object. However, only the <code>RIXMLProvider</code>
+ * implementation can set an <code>XmlReader</code> object and an
+ * <code>XmlWriter</code> object. A <code>WebRowSet</code> object uses the
+ * <code>XmlReader</code> object to read data in XML format to populate itself with that
+ * data. It uses the <code>XmlWriter</code> object to write itself to a stream or
+ * <code>java.io.Writer</code> object in XML format.
+ * <P>
+ * <h3>1.0 Naming Convention for Implementations</h3>
+ * As a guide to naming <code>SyncProvider</code>
+ * implementations, the following should be noted:
+ * <UL>
+ * <li>The name for a <code>SyncProvider</code> implementation
+ * is its fully qualified class name.
+ * <li>It is recommended that vendors supply a
+ * <code>SyncProvider</code> implementation in a package named <code>providers</code>.
+ * </UL>
+ * <p>
+ * For instance, if a vendor named Fred, Inc. offered a
+ * <code>SyncProvider</code> implementation, you could have the following:
+ * <PRE>
+ * Vendor name: Fred, Inc.
+ * Domain name of vendor: com.fred
+ * Package name: com.fred.providers
+ * SyncProvider implementation class name: HighAvailabilityProvider
+ *
+ * Fully qualified class name of SyncProvider implementation:
+ * com.fred.providers.HighAvailabilityProvider
+ * </PRE>
+ * <P>
+ * The following line of code uses the fully qualified name to register
+ * this implementation with the <code>SyncFactory</code> static instance.
+ * <PRE>
+ * SyncFactory.registerProvider(
+ * "com.fred.providers.HighAvailabilityProvider");
+ * </PRE>
+ * <P>
+ * The default <code>SyncProvider</code> object provided with the reference
+ * implementation uses the following name:
+ * <pre>
+ * com.sun.rowset.providers.RIOptimisticProvider
+ * </pre>
+ * <p>
+ * A vendor can register a <code>SyncProvider</code> implementation class name
+ * with Sun Microsystems, Inc. by sending email to jdbc@sun.com.
+ * Sun will maintain a database listing the
+ * available <code>SyncProvider</code> implementations for use with compliant
+ * <code>RowSet</code> implementations. This database will be similar to the
+ * one already maintained to list available JDBC drivers.
+ * <P>
+ * Vendors should refer to the reference implementation synchronization
+ * providers for additional guidance on how to implement a new
+ * <code>SyncProvider</code> implementation.
+ *
+ * <h3>2.0 How a <code>RowSet</code> Object Gets Its Provider</h3>
+ *
+ * A disconnected <code>Rowset</code> object may get access to a
+ * <code>SyncProvider</code> object in one of the following two ways:
+ * <UL>
+ * <LI>Using a constructor<BR>
+ * <PRE>
+ * CachedRowSet crs = new CachedRowSet(
+ * "com.fred.providers.HighAvailabilitySyncProvider");
+ * </PRE>
+ * <LI>Using the <code>setSyncProvider</code> method
+ * <PRE>
+ * CachedRowSet crs = new CachedRowSet();
+ * crs.setSyncProvider("com.fred.providers.HighAvailabilitySyncProvider");
+ * </PRE>
+
+ * </UL>
+ * <p>
+ * By default, the reference implementations of the <code>RowSet</code> synchronization
+ * providers are always available to the Java platform.
+ * If no other pluggable synchronization providers have been correctly
+ * registered, the <code>SyncFactory</code> will automatically generate
+ * an instance of the default <code>SyncProvider</code> reference implementation.
+ * Thus, in the preceding code fragment, if no implementation named
+ * <code>com.fred.providers.HighAvailabilitySyncProvider</code> has been
+ * registered with the <code>SyncFactory</code> instance, <i>crs</i> will be
+ * assigned the default provider in the reference implementation, which is
+ * <code>com.sun.rowset.providers.RIOptimisticProvider</code>.
+ * <p>
+ * <h3>3.0 Violations and Synchronization Issues</h3>
+ * If an update between a disconnected <code>RowSet</code> object
+ * and a data source violates
+ * the original query or the underlying data source constraints, this will
+ * result in undefined behavior for all disconnected <code>RowSet</code> implementations
+ * and their designated <code>SyncProvider</code> implementations.
+ * Not defining the behavior when such violations occur offers greater flexibility
+ * for a <code>SyncProvider</code>
+ * implementation to determine its own best course of action.
+ * <p>
+ * A <code>SyncProvider</code> implementation
+ * may choose to implement a specific handler to
+ * handle a subset of query violations.
+ * However if an original query violation or a more general data source constraint
+ * violation is not handled by the <code>SyncProvider</code> implementation,
+ * all <code>SyncProvider</code>
+ * objects must throw a <code>SyncProviderException</code>.
+ * <p>
+ * <h3>4.0 Updatable SQL VIEWs</h3>
+ * It is possible for any disconnected or connected <code>RowSet</code> object to be populated
+ * from an SQL query that is formulated originally from an SQL <code>VIEW</code>.
+ * While in many cases it is possible for an update to be performed to an
+ * underlying view, such an update requires additional metadata, which may vary.
+ * The <code>SyncProvider</code> class provides two constants to indicate whether
+ * an implementation supports updating an SQL <code>VIEW</code>.
+ * <ul>
+ * <li><code><b>NONUPDATABLE_VIEW_SYNC</b></code> - Indicates that a <code>SyncProvider</code>
+ * implementation does not support synchronization with an SQL <code>VIEW</code> as the
+ * underlying source of data for the <code>RowSet</code> object.
+ * <li><code><b>UPDATABLE_VIEW_SYNC</b></code> - Indicates that a
+ * <code>SyncProvider</code> implementation
+ * supports synchronization with an SQL <code>VIEW</code> as the underlying source
+ * of data.
+ * </ul>
+ * <P>
+ * The default is for a <code>RowSet</code> object not to be updatable if it was
+ * populated with data from an SQL <code>VIEW</code>.
+ * <P>
+ * <h3>5.0 <code>SyncProvider</code> Constants</h3>
+ * The <code>SyncProvider</code> class provides three sets of constants that
+ * are used as return values or parameters for <code>SyncProvider</code> methods.
+ * <code>SyncProvider</code> objects may be implemented to perform synchronization
+ * between a <code>RowSet</code> object and its underlying data source with varying
+ * degrees of of care. The first group of constants indicate how synchronization
+ * is handled. For example, <code>GRADE_NONE</code> indicates that a
+ * <code>SyncProvider</code> object will not take any care to see what data is
+ * valid and will simply write the <code>RowSet</code> data to the data source.
+ * <code>GRADE_MODIFIED_AT_COMMIT</code> indicates that the provider will check
+ * only modified data for validity. Other grades check all data for validity
+ * or set locks when data is modified or loaded.
+ * <OL>
+ * <LI>Constants to indicate the synchronization grade of a
+ * <code>SyncProvider</code> object
+ * <UL>
+ * <LI>SyncProvider.GRADE_NONE
+ * <LI>SyncProvider.GRADE_MODIFIED_AT_COMMIT
+ * <LI>SyncProvider.GRADE_CHECK_ALL_AT_COMMIT
+ * <LI>SyncProvider.GRADE_LOCK_WHEN_MODIFIED
+ * <LI>SyncProvider.GRADE_LOCK_WHEN_LOADED
+ * </UL>
+ * <LI>Constants to indicate what locks are set on the data source
+ * <UL>
+ * <LI>SyncProvider.DATASOURCE_NO_LOCK
+ * <LI>SyncProvider.DATASOURCE_ROW_LOCK
+ * <LI>SyncProvider.DATASOURCE_TABLE_LOCK
+ * <LI>SyncProvider.DATASOURCE_DB_LOCK
+ * </UL>
+ * <LI>Constants to indicate whether a <code>SyncProvider</code> object can
+ * perform updates to an SQL <code>VIEW</code> <BR>
+ * These constants are explained in the preceding section (4.0).
+ * <UL>
+ * <LI>SyncProvider.UPDATABLE_VIEW_SYNC
+ * <LI>SyncProvider.NONUPDATABLE_VIEW_SYNC
+ * </UL>
+ * </OL>
+ *
+ * @author Jonathan Bruce
+ * @see javax.sql.rowset.spi.SyncFactory
+ * @see javax.sql.rowset.spi.SyncFactoryException
+ */
+public abstract class SyncProvider {
+
+ /**
+ * Creates a default <code>SyncProvider</code> object.
+ */
+ public SyncProvider() {
+ }
+
+ /**
+ * Returns the unique identifier for this <code>SyncProvider</code> object.
+ *
+ * @return a <code>String</code> object with the fully qualified class name of
+ * this <code>SyncProvider</code> object
+ */
+ public abstract String getProviderID();
+
+ /**
+ * Returns a <code>javax.sql.RowSetReader</code> object, which can be used to
+ * populate a <code>RowSet</code> object with data.
+ *
+ * @return a <code>javax.sql.RowSetReader</code> object
+ */
+ public abstract RowSetReader getRowSetReader();
+
+ /**
+ * Returns a <code>javax.sql.RowSetWriter</code> object, which can be
+ * used to write a <code>RowSet</code> object's data back to the
+ * underlying data source.
+ *
+ * @return a <code>javax.sql.RowSetWriter</code> object
+ */
+ public abstract RowSetWriter getRowSetWriter();
+
+ /**
+ * Returns a constant indicating the
+ * grade of synchronization a <code>RowSet</code> object can expect from
+ * this <code>SyncProvider</code> object.
+ *
+ * @return an int that is one of the following constants:
+ * SyncProvider.GRADE_NONE,
+ * SyncProvider.GRADE_CHECK_MODIFIED_AT_COMMIT,
+ * SyncProvider.GRADE_CHECK_ALL_AT_COMMIT,
+ * SyncProvider.GRADE_LOCK_WHEN_MODIFIED,
+ * SyncProvider.GRADE_LOCK_WHEN_LOADED
+ */
+ public abstract int getProviderGrade();
+
+
+ /**
+ * Sets a lock on the underlying data source at the level indicated by
+ * <i>datasource_lock</i>. This should cause the
+ * <code>SyncProvider</code> to adjust its behavior by increasing or
+ * decreasing the level of optimism it provides for a successful
+ * synchronization.
+ *
+ * @param datasource_lock one of the following constants indicating the severity
+ * level of data source lock required:
+ * <pre>
+ * SyncProvider.DATASOURCE_NO_LOCK,
+ * SyncProvider.DATASOURCE_ROW_LOCK,
+ * SyncProvider.DATASOURCE_TABLE_LOCK,
+ * SyncProvider.DATASOURCE_DB_LOCK,
+ * </pre>
+ * @throws SyncProviderException if an unsupported data source locking level
+ * is set.
+ * @see #getDataSourceLock
+ */
+ public abstract void setDataSourceLock(int datasource_lock)
+ throws SyncProviderException;
+
+ /**
+ * Returns the current data source lock severity level active in this
+ * <code>SyncProvider</code> implementation.
+ *
+ * @return a constant indicating the current level of data source lock
+ * active in this <code>SyncProvider</code> object;
+ * one of the following:
+ * <pre>
+ * SyncProvider.DATASOURCE_NO_LOCK,
+ * SyncProvider.DATASOURCE_ROW_LOCK,
+ * SyncProvider.DATASOURCE_TABLE_LOCK,
+ * SyncProvider.DATASOURCE_DB_LOCK
+ * </pre>
+ * @throws SyncProviderExceptiom if an error occurs determining the data
+ * source locking level.
+ * @see #setDataSourceLock
+
+ */
+ public abstract int getDataSourceLock()
+ throws SyncProviderException;
+
+ /**
+ * Returns whether this <code>SyncProvider</code> implementation
+ * can perform synchronization between a <code>RowSet</code> object
+ * and the SQL <code>VIEW</code> in the data source from which
+ * the <code>RowSet</code> object got its data.
+ *
+ * @return an <code>int</code> saying whether this <code>SyncProvider</code>
+ * object supports updating an SQL <code>VIEW</code>; one of the
+ * following:
+ * SyncProvider.UPDATABLE_VIEW_SYNC,
+ * SyncProvider.NONUPDATABLE_VIEW_SYNC
+ */
+ public abstract int supportsUpdatableView();
+
+ /**
+ * Returns the release version of this <code>SyncProvider</code> instance.
+ *
+ * @return a <code>String</code> detailing the release version of the
+ * <code>SyncProvider</code> implementation
+ */
+ public abstract String getVersion();
+
+ /**
+ * Returns the vendor name of this <code>SyncProvider</code> instance
+ *
+ * @return a <code>String</code> detailing the vendor name of this
+ * <code>SyncProvider</code> implementation
+ */
+ public abstract String getVendor();
+
+ /*
+ * Standard description of synchronization grades that a SyncProvider
+ * could provide.
+ */
+
+ /**
+ * Indicates that no synchronization with the originating data source is
+ * provided. A <code>SyncProvider</code>
+ * implementation returning this grade will simply attempt to write
+ * updates in the <code>RowSet</code> object to the underlying data
+ * source without checking the validity of any data.
+ *
+ */
+ public static int GRADE_NONE = 1;
+
+ /**
+ * Indicates a low level optimistic synchronization grade with
+ * respect to the originating data source.
+ *
+ * A <code>SyncProvider</code> implementation
+ * returning this grade will check only rows that have changed.
+ *
+ */
+ public static int GRADE_CHECK_MODIFIED_AT_COMMIT = 2;
+
+ /**
+ * Indicates a high level optimistic synchronization grade with
+ * respect to the originating data source.
+ *
+ * A <code>SyncProvider</code> implementation
+ * returning this grade will check all rows, including rows that have not
+ * changed.
+ */
+ public static int GRADE_CHECK_ALL_AT_COMMIT = 3;
+
+ /**
+ * Indicates a pessimistic synchronization grade with
+ * respect to the originating data source.
+ *
+ * A <code>SyncProvider</code>
+ * implementation returning this grade will lock the row in the originating
+ * data source.
+ */
+ public static int GRADE_LOCK_WHEN_MODIFIED = 4;
+
+ /**
+ * Indicates the most pessimistic synchronization grade with
+ * respect to the originating
+ * data source. A <code>SyncProvider</code>
+ * implementation returning this grade will lock the entire view and/or
+ * table affected by the original statement used to populate a
+ * <code>RowSet</code> object.
+ */
+ public static int GRADE_LOCK_WHEN_LOADED = 5;
+
+ /**
+ * Indicates that no locks remain on the originating data source. This is the default
+ * lock setting for all <code>SyncProvider</code> implementations unless
+ * otherwise directed by a <code>RowSet</code> object.
+ */
+ public static int DATASOURCE_NO_LOCK = 1;
+
+ /**
+ * Indicates that a lock is placed on the rows that are touched by the original
+ * SQL statement used to populate the <code>RowSet</code> object
+ * that is using this <code>SyncProvider</code> object.
+ */
+ public static int DATASOURCE_ROW_LOCK = 2;
+
+ /**
+ * Indicates that a lock is placed on all tables that are touched by the original
+ * SQL statement used to populate the <code>RowSet</code> object
+ * that is using this <code>SyncProvider</code> object.
+ */
+ public static int DATASOURCE_TABLE_LOCK = 3;
+
+ /**
+ * Indicates that a lock is placed on the entire data source that is the source of
+ * data for the <code>RowSet</code> object
+ * that is using this <code>SyncProvider</code> object.
+ */
+ public static int DATASOURCE_DB_LOCK = 4;
+
+ /**
+ * Indicates that a <code>SyncProvider</code> implementation
+ * supports synchronization between a <code>RowSet</code> object and
+ * the SQL <code>VIEW</code> used to populate it.
+ */
+ public static int UPDATABLE_VIEW_SYNC = 5;
+
+ /**
+ * Indicates that a <code>SyncProvider</code> implementation
+ * does <B>not</B> support synchronization between a <code>RowSet</code>
+ * object and the SQL <code>VIEW</code> used to populate it.
+ */
+ public static int NONUPDATABLE_VIEW_SYNC = 6;
+}