/* * Copyright (c) 2003, 2006, Oracle and/or its affiliates. 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. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package com.sun.rowset.providers; import com.sun.rowset.JdbcRowSetResourceBundle; import javax.sql.*; import java.io.*; import javax.sql.rowset.spi.*; import com.sun.rowset.internal.*; /** * The reference implementation of a JDBC Rowset synchronization provider * providing optimistic synchronization with a relational datastore * using any JDBC technology-enabled driver. * <p> * <h3>1.0 Backgroud</h3> * This synchronization provider is registered with the * <code>SyncFactory</code> by default as the * <code>com.sun.rowset.providers.RIOptimisticProvider</code>. * As an extension of the <code>SyncProvider</code> abstract * class, it provides the reader and writer classes required by disconnected * rowsets as <code>javax.sql.RowSetReader</code> and <code>javax.sql.RowSetWriter</code> * interface implementations. As a reference implementation, * <code>RIOptimisticProvider</code> provides a * fully functional implementation offering a medium grade classification of * syncrhonization, namely GRADE_CHECK_MODIFIED_AT_COMMIT. A * disconnected <code>RowSet</code> implementation using the * <code>RIOptimisticProvider</code> can expect the writer to * check only rows that have been modified in the <code>RowSet</code> against * the values in the data source. If there is a conflict, that is, if a value * in the data source has been changed by another party, the * <code>RIOptimisticProvider</code> will not write any of the changes to the data * source and will throw a <code>SyncProviderException</code> object. * * <h3>2.0 Usage</h3> * Standard disconnected <code>RowSet</code> implementations may opt to use this * <code>SyncProvider</code> implementation in one of two ways: * <OL> * <LI>By specifically calling the <code>setSyncProvider</code> method defined in the <code>CachedRowSet</code> interface * <pre> * CachedRowset crs = new FooCachedRowSetImpl(); * crs.setSyncProvider("com.sun.rowset.providers.RIOptimisticProvider"); * </pre> * <LI>By specifying it in the constructor of the <code>RowSet</code> * implementation * <pre> * CachedRowset crs = new FooCachedRowSetImpl( * "com.sun.rowset.providers.RIOptimisticProvider"); * </pre> * </OL> * Note that because the <code>RIOptimisticProvider</code> implementation is * the default provider, it will always be the provider when no provider ID is * specified to the constructor. * <P> * See the standard <code>RowSet</code> reference implementations in the * <code>com.sun.rowset</code> package for more details. * * @author Jonathan Bruce * @see javax.sql.rowset.spi.SyncProvider * @see javax.sql.rowset.spi.SyncProviderException * @see javax.sql.rowset.spi.SyncFactory * @see javax.sql.rowset.spi.SyncFactoryException * */ public final class RIOptimisticProvider extends SyncProvider implements Serializable { private CachedRowSetReader reader; private CachedRowSetWriter writer; /** * The unique provider indentifier. */ private String providerID = "com.sun.rowset.providers.RIOptimisticProvider"; /** * The vendor name of this SyncProvider implementation */ private String vendorName = "Sun Microsystems Inc."; /** * The version number of this SyncProvider implementation */ private String versionNumber = "1.0"; /** * ResourceBundle */ private JdbcRowSetResourceBundle resBundle; /** * Creates an <code>RIOptimisticProvider</code> object initialized with the * fully qualified class name of this <code>SyncProvider</code> implementation * and a default reader and writer. * <P> * This provider is available to all disconnected <code>RowSet</code> implementations * as the default persistence provider. */ public RIOptimisticProvider() { providerID = this.getClass().getName(); reader = new CachedRowSetReader(); writer = new CachedRowSetWriter(); try { resBundle = JdbcRowSetResourceBundle.getJdbcRowSetResourceBundle(); } catch(IOException ioe) { throw new RuntimeException(ioe); } } /** * Returns the <code>'javax.sql.rowset.providers.RIOptimisticProvider'</code> * provider identification string. * * @return String Provider ID of this persistence provider */ public String getProviderID() { return providerID; } /** * Returns the <code>javax.sql.RowSetWriter</code> object for this * <code>RIOptimisticProvider</code> object. This is the writer that will * write changes made to the <code>Rowset</code> object back to the data source. * * @return the <code>javax.sql.RowSetWriter</code> object for this * <code>RIOptimisticProvider</code> object */ public RowSetWriter getRowSetWriter() { try { writer.setReader(reader); } catch (java.sql.SQLException e) {} return writer; } /** * Returns the <code>javax.sql.RowSetReader</code> object for this * <code>RIOptimisticProvider</code> object. This is the reader that will * populate a <code>RowSet</code> object using this <code>RIOptimisticProvider</code>. * * @return the <code>javax.sql.RowSetReader</code> object for this * <code>RIOptimisticProvider</code> object */ public RowSetReader getRowSetReader() { return reader; } /** * Returns the <code>SyncProvider</code> grade of synchronization that * <code>RowSet</code> objects can expect when using this * implementation. As an optimisic synchonization provider, the writer * will only check rows that have been modified in the <code>RowSet</code> * object. */ public int getProviderGrade() { return SyncProvider.GRADE_CHECK_MODIFIED_AT_COMMIT; } /** * Modifies the data source lock severity according to the standard * <code>SyncProvider</code> classifications. * * @param datasource_lock An <code>int</code> indicating the level of locking to be * set; must be one of the following constants: * <PRE> * SyncProvider.DATASOURCE_NO_LOCK, * SyncProvider.DATASOURCE_ROW_LOCK, * SyncProvider.DATASOURCE_TABLE_LOCK, * SyncProvider.DATASOURCE_DB_LOCk * </PRE> * @throws SyncProviderException if the parameter specified is not * <code>SyncProvider.DATASOURCE_NO_LOCK</code> */ public void setDataSourceLock(int datasource_lock) throws SyncProviderException { if(datasource_lock != SyncProvider.DATASOURCE_NO_LOCK ) { throw new SyncProviderException(resBundle.handleGetObject("riop.locking").toString()); } } /** * Returns the active data source lock severity in this * reference implementation of the <code>SyncProvider</code> * abstract class. * * @return <code>SyncProvider.DATASOURCE_NO_LOCK</code>. * The reference implementation does not support data source locks. */ public int getDataSourceLock() throws SyncProviderException { return SyncProvider.DATASOURCE_NO_LOCK; } /** * Returns the supported updatable view abilities of the * reference implementation of the <code>SyncProvider</code> * abstract class. * * @return <code>SyncProvider.NONUPDATABLE_VIEW_SYNC</code>. The * the reference implementation does not support updating tables * that are the source of a view. */ public int supportsUpdatableView() { return SyncProvider.NONUPDATABLE_VIEW_SYNC; } /** * Returns the release version ID of the Reference Implementation Optimistic * Synchronization Provider. * * @return the <code>String</code> detailing the version number of this SyncProvider */ public String getVersion() { return this.versionNumber; } /** * Returns the vendor name of the Reference Implemntation Optimistic * Syncchronication Provider * * @return the <code>String</code> detailing the vendor name of this * SyncProvider */ public String getVendor() { return this.vendorName; } }