package org.apache.ojb.broker.platforms;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache ObjectRelationalBridge" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache ObjectRelationalBridge", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import java.io.ByteArrayInputStream;
import java.lang.reflect.Field;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.Types;
import oracle.sql.CLOB;
import java.io.CharArrayReader;
import oracle.sql.BLOB;
//import java.io.Writer;
//import oracle.jdbc.driver.OracleResultSet;

/**
 *  This class is a concrete implementation of <code>Platform</code>. Provides
 *  an implementation that works around some issues with Oracle in general and
 *  Oracle's Thin driver in particular..
 *
 * @author <a href="mailto:thma@apache.org">Thomas Mahler<a>
 * @version $Id: PlatformOracleImpl.java,v 1.8 2002/10/13 10:22:18 olegnitz Exp $
 */

public class PlatformOracleImpl extends PlatformDefaultImpl {

	/**
	 * Initializes the ESCAPE_PROCESSING member in StatementsForClass.
	 * @see Platform#initializeJdbcConnection(Connection)
	 */
	public void initializeJdbcConnection(Connection conn) throws PlatformException
	{
	    super.initializeJdbcConnection(conn);
	}

    /**
     * In Oracle we set escape processing explizit 'true' after a
     * statement was created.
     */
    public void afterStatementCreate(Statement stmt) throws PlatformException
    {
        try
        {
            stmt.setEscapeProcessing(true);
        }
        catch (SQLException e)
        {
            throw new PlatformException("Could not set escape processing", e);
        }
    }

    /**
     *  For objects beyond 4k, weird things happen in Oracle if you try
     *  to use "setBytes", so for all cases it's better to use setBinaryStream.
     *  Oracle also requires a change in the resultset type of the prepared
     *  statement.
     * 	MBAIRD NOTE: BLOBS may not work with Oracle database/thin driver versions
     *  prior to 8.1.6.
     *
     *  @see Platform#setObjectForStatement
     */
	public void setObjectForStatement(PreparedStatement ps, int index, Object value, int sqlType) throws SQLException
	{
		if (((sqlType == Types.VARBINARY) || (sqlType == Types.LONGVARBINARY) || (sqlType == Types.BLOB)) && (value instanceof byte[]))
		{
			byte buf[] = (byte[])value;
			ByteArrayInputStream inputStream = new ByteArrayInputStream(buf);
			changePreparedStatementResultSetType(ps);
			ps.setBinaryStream(index, inputStream, buf.length);
		}
	   else if (sqlType == Types.CLOB)
       {
            CharArrayReader inputStream = new CharArrayReader((char[]) value);
             ps.setCharacterStream(index, inputStream, ((char[])value).length);
        }
    	else if (value instanceof Double)
		{
			// workaround for the bug in Oracle thin driver
			ps.setDouble(index, ((Double) value).doubleValue());
		}
		else
		{
			super.setObjectForStatement(ps, index, value, sqlType);
		}
    }

	/**
     *  Attempts to modify a private member in the Oracle thin driver's resultset
     *  to allow proper setting of large binary streams.
	 */
    private void changePreparedStatementResultSetType(PreparedStatement ps)
    {
        try
        {
            final Field f = ps.getClass().getSuperclass().getDeclaredField("m_userRsetType");
            AccessController.doPrivileged(
                new PrivilegedAction()
                {
                    public Object run()
                    {
                        f.setAccessible(true);
                        return null;
                    }
                });
            f.setInt(ps, 1);
            f.setAccessible(false);
        } catch (Exception e)
        {
            e.printStackTrace();
        }
    }

    /**
     * Get join syntax type for this RDBMS - one on of the constants from JoinSyntaxType interface
     */
    public byte getJoinSyntaxType()
    {
        return ORACLE_JOIN_SYNTAX;
    }
}