/*

 * 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.

 *

 * 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.

 *

 * 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 identifier.

     */

    private String providerID = "com.sun.rowset.providers.RIOptimisticProvider";

    /**

     * The vendor name of this SyncProvider implementation

     */

    private String vendorName = "Oracle Corporation";

    /**

     * 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 Implementation Optimistic

     * Synchronization Provider

     *

     * @return the <code>String</code> detailing the vendor name of this

     *      SyncProvider

     */

    public String getVendor() {

        return this.vendorName;

    }

    private void readObject(ObjectInputStream ois) throws IOException, ClassNotFoundException {

        // Default state initialization happens here

        ois.defaultReadObject();

        // Initialization of transient Res Bundle happens here .

        try {

           resBundle = JdbcRowSetResourceBundle.getJdbcRowSetResourceBundle();

        } catch(IOException ioe) {

            throw new RuntimeException(ioe);

        }

    }

    static final long serialVersionUID =-3143367176751761936L;

}