/**
 * JOnAS: Java(TM) Open Application Server
 * Copyright (C) 1999-2010 Bull S.A.S.
 * Contact: jonas-team@ow2.org
 *
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * --------------------------------------------------------------------------
 * $Id: PreparedStatementWrapper.java 20169 2010-08-16 14:15:38Z benoitf $
 * --------------------------------------------------------------------------
 *
 */

package org.ow2.jonas.resource.internal.cm.sql;

import java.io.InputStream;
import java.io.Reader;
import java.sql.NClob;
import java.sql.RowId;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.sql.SQLXML;
import java.sql.Types;
import java.io.InputStream;
import java.io.Reader;
import java.math.BigDecimal;
import java.net.URL;
import java.sql.Array;
import java.sql.Blob;
import java.sql.Clob;
import java.sql.Connection;
import java.sql.Date;
import java.sql.ParameterMetaData;
import java.sql.PreparedStatement;
import java.sql.Ref;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.SQLWarning;
import java.sql.Time;
import java.sql.Timestamp;
import java.util.Arrays;
import java.util.Calendar;

import org.objectweb.util.monolog.api.BasicLevel;
import org.objectweb.util.monolog.api.Logger;

/**
 * This class <b>PreparedStatementWrapper</b> wrap an SQL {@link PreparedStatement}
 * @author Eric HARDESTY
 */
public class PreparedStatementWrapper implements PreparedStatement {

    /**
     * Prime numbers
     */
    private static final int[] PRIME_NUMBERS = new int[] {11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47};

    /**
     * Wrapped preparedstatement object
     */
    private PreparedStatement pstmt = null;

    /**
     * User used for the preparedstatement
     */
    private String user = null;

    /**
     * SQL statement
     */
    private String sql = null;

    /**
     * This object has been marked invalid ?
     */
    private boolean invalid = false;

    /**
     * This object is now closed ?
     */
    private boolean closed = false;

    /**
     * Hashcode of this object
     */
    private int hashCode;

    /**
     * Type of result set. one of <code>ResultSet.TYPE_FORWARD_ONLY</code>,
     * <code>ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or
     * <code>ResultSet.TYPE_SCROLL_SENSITIVE</code>
     */
    private int resultSetType = -1;

    /**
     * Concurrency type for result set; one of
     * <code>ResultSet.CONCUR_READ_ONLY</code> or
     * <code>ResultSet.CONCUR_UPDATABLE</code>
     */
    private int resultSetConcurrency = -1;

    /**
     * Holdability, One of the value :
     * <code>ResultSet.HOLD_CURSORS_OVER_COMMIT</code> or
     * <code>ResultSet.CLOSE_CURSORS_AT_COMMIT</code>
     */
    private int resultSetHoldability = -1;

    /**
     * A flag indicating whether auto-generated keys should be returned; one of
     * <code>Statement.RETURN_GENERATED_KEYS</code> or
     * <code>Statement.NO_GENERATED_KEYS</code>
     */
    private int autoGeneratedKeys = -1;

    /**
     * An array of column indexes indicating the columns that should be returned
     * from the inserted row or rows
     */
    private int[] columnIndexes = null;

    /**
     * An array of column names indicating the columns that should be returned
     * from the inserted row or rows
     */
    private String[] columnNames = null;

    /**
     * Logger used for traces
     */
    private final Logger trace;

    /**
     * Direction was Changed ? need to reset or not
     */
    private boolean setFetchDirectionCalled = false;

    /**
     * Escape processing was changed ? need to reset or not
     */
    private boolean setEscapeProcessingCalled = false;

    /**
     * Max field size ? need to reset or not
     */
    private boolean setMaxFieldSizeCalled = false;

    /**
     * Debug logging enabled ?
     */
    private final boolean isDebugLogging;

    /**
     * Creates a <code>PreparedStatementWrapper</code> object.
     * This constructor is private and is used by other constructors.
     * It contains all constructors elements.
     * @param user the user used for accessing the connection
     * @param sql a <code>String</code> object that is the SQL statement to be
     *        sent to the database; may contain one or more ? IN parameters
     * @param resultSetType a result set type; one of
     *        <code>ResultSet.TYPE_FORWARD_ONLY</code>,
     *        <code>ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or
     *        <code>ResultSet.TYPE_SCROLL_SENSITIVE</code>
     * @param resultSetConcurrency a concurrency type; one of
     *        <code>ResultSet.CONCUR_READ_ONLY</code> or
     *        <code>ResultSet.CONCUR_UPDATABLE</code>
     * @param resultSetHoldability one of the following <code>ResultSet</code>
     *        constants: <code>ResultSet.HOLD_CURSORS_OVER_COMMIT</code> or
     *        <code>ResultSet.CLOSE_CURSORS_AT_COMMIT</code>
     * @param autoGeneratedKeys a flag indicating whether auto-generated keys
     *        should be returned; one of
     *        <code>Statement.RETURN_GENERATED_KEYS</code> or
     *        <code>Statement.NO_GENERATED_KEYS</code>
     * @param columnIndexes an array of column indexes indicating the columns
     *        that should be returned from the inserted row or rows
     * @param columnNames an array of column names indicating the columns that
     *        should be returned from the inserted row or rows
     * @param trace the logger to use for logging purpose
     * @param isDebugLogging if true, log the debug event in the logger
     */
    private PreparedStatementWrapper(final String user, final String sql, final int resultSetType,
            final int resultSetConcurrency, final int resultSetHoldability, final int autoGeneratedKeys,
            final int[] columnIndexes, final String[] columnNames, final Logger trace, final boolean isDebugLogging) {

        this.user = user;
        this.sql = sql;
        this.resultSetType = resultSetType;
        this.resultSetConcurrency = resultSetConcurrency;
        this.resultSetHoldability = resultSetHoldability;
        this.autoGeneratedKeys = autoGeneratedKeys;
        this.columnIndexes = columnIndexes;
        this.columnNames = columnNames;
        this.trace = trace;

        int i = 0;
        // hashcode computing
        if (sql != null) {
            hashCode = sql.hashCode();
        } else {
            hashCode = PRIME_NUMBERS[i++];
        }
        if (user != null) {
            hashCode ^= user.hashCode();
        } else {
            hashCode ^= PRIME_NUMBERS[i++];
        }
        hashCode ^= (resultSetType * PRIME_NUMBERS[i++]);
        hashCode ^= (resultSetConcurrency * PRIME_NUMBERS[i++]);
        hashCode ^= (resultSetHoldability * PRIME_NUMBERS[i++]);
        hashCode ^= (autoGeneratedKeys * PRIME_NUMBERS[i++]);
        if (columnIndexes != null) {
            hashCode ^= columnIndexes.hashCode();
        } else {
            hashCode ^= PRIME_NUMBERS[i++];
        }
        if (columnNames != null) {
            hashCode ^= columnNames.hashCode();
        } else {
            hashCode ^= PRIME_NUMBERS[i++];
        }
        this.isDebugLogging = isDebugLogging;
    }



    /**
     * Creates a <code>PreparedStatementWrapper</code> object that will
     * generate <code>ResultSet</code> objects with the given type and
     * concurrency. This method is the same as the <code>prepareStatement</code>
     * method above, but it allows the default result set type and concurrency
     * to be overridden.
     * @param user the user used for accessing the connection
     * @param sql a <code>String</code> object that is the SQL statement to be
     *        sent to the database; may contain one or more ? IN parameters
     * @param resultSetType a result set type; one of
     *        <code>ResultSet.TYPE_FORWARD_ONLY</code>,
     *        <code>ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or
     *        <code>ResultSet.TYPE_SCROLL_SENSITIVE</code>
     * @param resultSetConcurrency a concurrency type; one of
     *        <code>ResultSet.CONCUR_READ_ONLY</code> or
     *        <code>ResultSet.CONCUR_UPDATABLE</code>
     * @param trace the logger to use for logging purpose
     * @param isDebugLogging if true, log the debug event in the logger
     * @since JDK 1.2
     */
    public PreparedStatementWrapper(final String user, final String sql, final int resultSetType,
            final int resultSetConcurrency, final Logger trace, final boolean isDebugLogging) {
        this(user, sql, resultSetType, resultSetConcurrency, -1, -1, null, null, trace, isDebugLogging);
    }

    /**
     * Creates a <code>PreparedStatementWrapper</code> object that will
     * generate <code>ResultSet</code> objects with the given type,
     * concurrency, and holdability.
     * <P>
     * This method is the same as the <code>prepareStatement</code> method
     * above, but it allows the default result set type, concurrency, and
     * holdability to be overridden.
     * @param user the user used for accessing the connection
     * @param sql a <code>String</code> object that is the SQL statement to be
     *        sent to the database; may contain one or more ? IN parameters
     * @param resultSetType one of the following <code>ResultSet</code>
     *        constants: <code>ResultSet.TYPE_FORWARD_ONLY</code>,
     *        <code>ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or
     *        <code>ResultSet.TYPE_SCROLL_SENSITIVE</code>
     * @param resultSetConcurrency one of the following <code>ResultSet</code>
     *        constants: <code>ResultSet.CONCUR_READ_ONLY</code> or
     *        <code>ResultSet.CONCUR_UPDATABLE</code>
     * @param resultSetHoldability one of the following <code>ResultSet</code>
     *        constants: <code>ResultSet.HOLD_CURSORS_OVER_COMMIT</code> or
     *        <code>ResultSet.CLOSE_CURSORS_AT_COMMIT</code>
     * @param trace the logger to use for logging purpose
     * @param isDebugLogging if true, log the debug event in the logger
     * @since JDK 1.4
     */
    public PreparedStatementWrapper(final String user, final String sql, final int resultSetType,
            final int resultSetConcurrency, final int resultSetHoldability, final Logger trace, final boolean isDebugLogging) {
        this(user, sql, resultSetType, resultSetConcurrency, resultSetHoldability, -1, null, null, trace, isDebugLogging);
    }

    /**
     * Creates a default <code>PreparedStatementWrapper</code> object that has
     * the capability to retrieve auto-generated keys. The given constant tells
     * the driver whether it should make auto-generated keys available for
     * retrieval. This parameter is ignored if the SQL statement is not an
     * <code>INSERT</code> statement.
     * @param user the user used for accessing the connection
     * @param sql an SQL statement that may contain one or more '?' IN parameter
     *        placeholders
     * @param autoGeneratedKeys a flag indicating whether auto-generated keys
     *        should be returned; one of
     *        <code>Statement.RETURN_GENERATED_KEYS</code> or
     *        <code>Statement.NO_GENERATED_KEYS</code>
     * @param trace the logger to use for logging purpose
     * @param isDebugLogging if true, log the debug event in the logger
     * @since JDK 1.4
     */
    public PreparedStatementWrapper(final String user, final String sql, final int autoGeneratedKeys, final Logger trace, final boolean isDebugLogging) {
        this(user, sql, -1, -1, -1, autoGeneratedKeys, null, null, trace, isDebugLogging);
    }

    /**
     * Creates a default <code>PreparedStatementWrapper</code> object capable
     * of returning the auto-generated keys designated by the given array. This
     * array contains the indexes of the columns in the target table that
     * contain the auto-generated keys that should be made available. This array
     * is ignored if the SQL statement is not an <code>INSERT</code>
     * statement.
     * <P>
     * An SQL statement with or without IN parameters can be pre-compiled and
     * stored in a <code>PreparedStatement</code> object. This object can then
     * be used to efficiently execute this statement multiple times.
     * @param user the user used for accessing the connection
     * @param sql an SQL statement that may contain one or more '?' IN parameter
     *        placeholders
     * @param columnIndexes an array of column indexes indicating the columns
     *        that should be returned from the inserted row or rows
     * @param trace the logger to use for logging purpose
     * @param isDebugLogging if true, log the debug event in the logger
     * @since JDK 1.4
     */
    public PreparedStatementWrapper(final String user, final String sql, final int[] columnIndexes, final Logger trace, final boolean isDebugLogging) {
        this(user, sql, -1, -1, -1, -1, columnIndexes, null, trace, isDebugLogging);
    }

    /**
     * Creates a default <code>PreparedStatementWrapper</code> object capable
     * of returning the auto-generated keys designated by the given array. This
     * array contains the names of the columns in the target table that contain
     * the auto-generated keys that should be returned. This array is ignored if
     * the SQL statement is not an <code>INSERT</code> statement.
     * <P>
     * An SQL statement with or without IN parameters can be pre-compiled and
     * stored in a <code>PreparedStatement</code> object. This object can then
     * be used to efficiently execute this statement multiple times.
     * @param user the user used for accessing the connection
     * @param sql an SQL statement that may contain one or more '?' IN parameter
     *        placeholders
     * @param columnNames an array of column names indicating the columns that
     *        should be returned from the inserted row or rows
     * @param trace the logger to use for logging purpose
     * @param isDebugLogging if true, log the debug event in the logger
     * @since JDK 1.4
     */
    public PreparedStatementWrapper(final String user, final String sql, final String[] columnNames, final Logger trace, final boolean isDebugLogging) {
        this(user, sql, -1, -1, -1, -1, null, columnNames, trace, isDebugLogging);
    }

    /**
     * Checks that this object is not in invalid state
     * @throws SQLException if object is in invalid mode
     */
    public void checkIfValid() throws SQLException {
        if (invalid) {
            SQLException se = new SQLException("PreparedStatement(" + this + ") is invalid.");
            trace.log(BasicLevel.ERROR, se);
            throw se;
        }

    }

    /**
     * Clears the values stored in the preparement. This is required as this
     * preparedstatement is reused
     */
    public void clearPstmtValues() {
        closed = false;
        try {
            pstmt.clearParameters();
            pstmt.clearBatch();
        } catch (Throwable ex) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Cannot clear parameters", ex);
            }
        }
        if (setEscapeProcessingCalled) {
            try {
                pstmt.setEscapeProcessing(true);
            } catch (Throwable ex) {
                if (isDebugLogging) {
                    trace.log(BasicLevel.DEBUG, "Cannot reset escape processing to true", ex);
                }
            }
        }
        if (setFetchDirectionCalled) {
            try {
                pstmt.setFetchDirection(ResultSet.FETCH_FORWARD);
            } catch (Throwable ex) {
                if (isDebugLogging) {
                    trace.log(BasicLevel.DEBUG, "Cannot set fetch direction to ResultSet.FETCH_FORWARD", ex);
                }
            }
        }
        if (setMaxFieldSizeCalled) {
            try {
                pstmt.setMaxFieldSize(0);
            } catch (Throwable ex) {
                if (isDebugLogging) {
                    trace.log(BasicLevel.DEBUG, "Cannot set max field size to 0", ex);
                }
            }
        }
        try {
            pstmt.setMaxRows(0);
        } catch (Throwable ex) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Cannot set max rows to 0", ex);
            }
        }
        try {
            pstmt.setQueryTimeout(0);
        } catch (Throwable ex) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Cannot set query timeout to 0", ex);
            }
        }
        try {
            pstmt.clearWarnings();
        } catch (Throwable ex) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Cannot clear warnings", ex);
            }
        }
    }

    /**
     * Close this object
     * @throws SQLException if object cannot be closed
     */
    public void closePstmt() throws SQLException {
        closed = true;
        pstmt.close();
    }

    /**
     * Destroy this preparestatement object, then it becomes closed and invalid
     * @throws SQLException if it cannot be closed
     */
    public void destroy() throws SQLException {
        if (isDebugLogging) {
            trace.log(BasicLevel.DEBUG, "" + this);
        }
        try {
            pstmt.close();
        } finally {
            invalid = true;
            closed = true;
        }
    }

    /**
     * @param stmt given statement for comparing it
     * @return true if given object is equals to this current object
     */
    public boolean equals(Object stmt) {
        if (stmt == null) {
            return false;
        }
        // different hashcode, cannot be equals
        if (this.hashCode != stmt.hashCode()) {
            return false;
        }

        // if got same hashcode, try to see if cast is ok.
        if (!(stmt instanceof PreparedStatementWrapper)) {
            return false;
        }
        PreparedStatementWrapper psw = (PreparedStatementWrapper) stmt;

        if (invalid) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Prepared Statement is invalid");
            }
            return false;
        }
        if (sql == null && psw.sql != null) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Stmt sql: " + psw.sql + " not equal to " + sql);
            }
            return false;
        }
        if (sql != null && !sql.equals(psw.sql)) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Stmt sql: " + psw.sql + " not equal to " + sql);
            }
            return false;
        }
        if (user == null && psw.user != null) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Stmt user: " + psw.user + " not equal to " + user);
            }
            return false;
        }
        if (user != null && !user.equals(psw.user)) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Stmt user: " + psw.user + " not equal to " + user);
            }
            return false;
        }
        if (resultSetType != psw.resultSetType) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Stmt resultSetType: " + psw.resultSetType + " not equal to "
                        + resultSetType);
            }
            return false;
        }
        if (resultSetConcurrency != psw.resultSetConcurrency) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Stmt resultSetConcurrency: " + psw.resultSetConcurrency + " not equal to "
                        + resultSetConcurrency);
            }
            return false;
        }
        if (resultSetHoldability != psw.resultSetHoldability) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Stmt resultSetHoldability: " + psw.resultSetHoldability + " not equal to "
                        + resultSetHoldability);
            }
            return false;
        }
        if (autoGeneratedKeys != psw.autoGeneratedKeys) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Stmt autoGeneratedKeys: " + psw.autoGeneratedKeys + " not equal to "
                        + autoGeneratedKeys);
            }
            return false;
        }
        if (!Arrays.equals(columnIndexes, psw.columnIndexes)) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Stmt columnIndexes: " + psw.columnIndexes + " not equal to "
                        + columnIndexes);
            }
            return false;
        }
        if (!Arrays.equals(columnNames, psw.columnNames)) {
            if (isDebugLogging) {
                trace.log(BasicLevel.DEBUG, "Stmt columnNames: " + psw.columnNames + " not equal to " + columnNames);
            }
            return false;
        }
        if (isDebugLogging) {
            trace.log(BasicLevel.DEBUG, "Stmt found at " + this);
        }
        return true;
    }

    /**
     * Close this object
     * @param val true/false
     */
    public void setClosed(boolean val) {
        closed = val;
    }

    /**
     * Sets the real prepared statement object on which we wrap calls
     * @param pstmt sql preparedstatement
     */
    public void setPreparedStatement(PreparedStatement pstmt) {
        this.pstmt = pstmt;
    }

    /***************************************************************************
     * Prepared Statment calls
     */

    /**
     * Adds a set of parameters to this <code>PreparedStatement</code>
     * object's batch of commands.
     * @exception SQLException if a database access error occurs
     * @see Statement#addBatch
     * @since 1.2
     */
    public void addBatch() throws SQLException {
        checkIfValid();
        pstmt.addBatch();
    }

    /**
     * Clears the current parameter values immediately.
     * <P>
     * In general, parameter values remain in force for repeated use of a
     * statement. Setting a parameter value automatically clears its previous
     * value. However, in some cases it is useful to immediately release the
     * resources used by the current parameter values; this can be done by
     * calling the method <code>clearParameters</code>.
     * @exception SQLException if a database access error occurs
     */
    public void clearParameters() throws SQLException {
        checkIfValid();
        pstmt.clearParameters();
    }

    /**
     * Executes the SQL statement in this <code>PreparedStatement</code>
     * object, which may be any kind of SQL statement. Some prepared statements
     * return multiple results; the <code>execute</code> method handles these
     * complex statements as well as the simpler form of statements handled by
     * the methods <code>executeQuery</code> and <code>executeUpdate</code>.
     * <P>
     * The <code>execute</code> method returns a <code>boolean</code> to
     * indicate the form of the first result. You must call either the method
     * <code>getResultSet</code> or <code>getUpdateCount</code> to retrieve
     * the result; you must call <code>getMoreResults</code> to move to any
     * subsequent result(s).
     * @return <code>true</code> if the first result is a
     *         <code>ResultSet</code> object; <code>false</code> if the
     *         first result is an update count or there is no result
     * @exception SQLException if a database access error occurs or an argument
     *            is supplied to this method
     * @see Statement#execute
     * @see Statement#getResultSet
     * @see Statement#getUpdateCount
     * @see Statement#getMoreResults
     */
    public boolean execute() throws SQLException {
        checkIfValid();
        return pstmt.execute();
    }

    // JDK1.4
    /**
     * Executes the given SQL statement, which may return multiple results, and
     * signals the driver that any auto-generated keys should be made available
     * for retrieval. The driver will ignore this signal if the SQL statement is
     * not an <code>INSERT</code> statement.
     * <P>
     * In some (uncommon) situations, a single SQL statement may return multiple
     * result sets and/or update counts. Normally you can ignore this unless you
     * are (1) executing a stored procedure that you know may return multiple
     * results or (2) you are dynamically executing an unknown SQL string.
     * <P>
     * The <code>execute</code> method executes an SQL statement and indicates
     * the form of the first result. You must then use the methods
     * <code>getResultSet</code> or <code>getUpdateCount</code> to retrieve
     * the result, and <code>getMoreResults</code> to move to any subsequent
     * result(s).
     * @param sql any SQL statement
     * @param autoGeneratedKeys a constant indicating whether auto-generated
     *        keys should be made available for retrieval using the method
     *        <code>getGeneratedKeys</code>; one of the following constants:
     *        <code>Statement.RETURN_GENERATED_KEYS</code> or
     *        <code>Statement.NO_GENERATED_KEYS</code>
     * @return <code>true</code> if the first result is a
     *         <code>ResultSet</code> object; <code>false</code> if it is an
     *         update count or there are no results
     * @exception SQLException if a database access error occurs or the second
     *            parameter supplied to this method is not
     *            <code>Statement.RETURN_GENERATED_KEYS</code> or
     *            <code>Statement.NO_GENERATED_KEYS</code>.
     * @see #getResultSet
     * @see #getUpdateCount
     * @see #getMoreResults
     * @see #getGeneratedKeys
     * @since 1.4
     */
    public boolean execute(String sql, int autoGeneratedKeys) throws SQLException {
        checkIfValid();
        return pstmt.execute(sql, autoGeneratedKeys);
    }

    // JDK1.4
    /**
     * Executes the given SQL statement, which may return multiple results, and
     * signals the driver that the auto-generated keys indicated in the given
     * array should be made available for retrieval. This array contains the
     * indexes of the columns in the target table that contain the
     * auto-generated keys that should be made available. The driver will ignore
     * the array if the given SQL statement is not an <code>INSERT</code>
     * statement.
     * <P>
     * Under some (uncommon) situations, a single SQL statement may return
     * multiple result sets and/or update counts. Normally you can ignore this
     * unless you are (1) executing a stored procedure that you know may return
     * multiple results or (2) you are dynamically executing an unknown SQL
     * string.
     * <P>
     * The <code>execute</code> method executes an SQL statement and indicates
     * the form of the first result. You must then use the methods
     * <code>getResultSet</code> or <code>getUpdateCount</code> to retrieve
     * the result, and <code>getMoreResults</code> to move to any subsequent
     * result(s).
     * @param sql any SQL statement
     * @param columnIndexes an array of the indexes of the columns in the
     *        inserted row that should be made available for retrieval by a call
     *        to the method <code>getGeneratedKeys</code>
     * @return <code>true</code> if the first result is a
     *         <code>ResultSet</code> object; <code>false</code> if it is an
     *         update count or there are no results
     * @exception SQLException if a database access error occurs or the elements
     *            in the <code>int</code> array passed to this method are not
     *            valid column indexes
     * @see #getResultSet
     * @see #getUpdateCount
     * @see #getMoreResults
     * @since 1.4
     */
    public boolean execute(String sql, int[] columnIndexes) throws SQLException {
        checkIfValid();
        return pstmt.execute(sql, columnIndexes);
    }

    // JDK1.4
    /**
     * Executes the given SQL statement, which may return multiple results, and
     * signals the driver that the auto-generated keys indicated in the given
     * array should be made available for retrieval. This array contains the
     * names of the columns in the target table that contain the auto-generated
     * keys that should be made available. The driver will ignore the array if
     * the given SQL statement is not an <code>INSERT</code> statement.
     * <P>
     * In some (uncommon) situations, a single SQL statement may return multiple
     * result sets and/or update counts. Normally you can ignore this unless you
     * are (1) executing a stored procedure that you know may return multiple
     * results or (2) you are dynamically executing an unknown SQL string.
     * <P>
     * The <code>execute</code> method executes an SQL statement and indicates
     * the form of the first result. You must then use the methods
     * <code>getResultSet</code> or <code>getUpdateCount</code> to retrieve
     * the result, and <code>getMoreResults</code> to move to any subsequent
     * result(s).
     * @param sql any SQL statement
     * @param columnNames an array of the names of the columns in the inserted
     *        row that should be made available for retrieval by a call to the
     *        method <code>getGeneratedKeys</code>
     * @return <code>true</code> if the next result is a
     *         <code>ResultSet</code> object; <code>false</code> if it is an
     *         update count or there are no more results
     * @exception SQLException if a database access error occurs or the elements
     *            of the <code>String</code> array passed to this method are
     *            not valid column names
     * @see #getResultSet
     * @see #getUpdateCount
     * @see #getMoreResults
     * @see #getGeneratedKeys
     * @since 1.4
     */
    public boolean execute(String sql, String[] columnNames) throws SQLException {
        checkIfValid();
        return pstmt.execute(sql, columnNames);
    }

    /**
     * Executes the SQL query in this <code>PreparedStatement</code> object
     * and returns the <code>ResultSet</code> object generated by the query.
     * @return a <code>ResultSet</code> object that contains the data produced
     *         by the query; never <code>null</code>
     * @exception SQLException if a database access error occurs or the SQL
     *            statement does not return a <code>ResultSet</code> object
     */
    public ResultSet executeQuery() throws SQLException {
        checkIfValid();
        return pstmt.executeQuery();
    }

    /**
     * Executes the SQL statement in this <code>PreparedStatement</code>
     * object, which must be an SQL <code>INSERT</code>, <code>UPDATE</code>
     * or <code>DELETE</code> statement; or an SQL statement that returns
     * nothing, such as a DDL statement.
     * @return either (1) the row count for <code>INSERT</code>,
     *         <code>UPDATE</code>, or <code>DELETE</code> statements or
     *         (2) 0 for SQL statements that return nothing
     * @exception SQLException if a database access error occurs or the SQL
     *            statement returns a <code>ResultSet</code> object
     */
    public int executeUpdate() throws SQLException {
        checkIfValid();
        return pstmt.executeUpdate();
    }

    // JDK1.4
    /**
     * Executes the given SQL statement and signals the driver with the given
     * flag about whether the auto-generated keys produced by this
     * <code>Statement</code> object should be made available for retrieval.
     * @param sql must be an SQL <code>INSERT</code>, <code>UPDATE</code>
     *        or <code>DELETE</code> statement or an SQL statement that
     *        returns nothing
     * @param autoGeneratedKeys a flag indicating whether auto-generated keys
     *        should be made available for retrieval; one of the following
     *        constants: <code>Statement.RETURN_GENERATED_KEYS</code>
     *         <code>Statement.NO_GENERATED_KEYS</code>
     * @return either the row count for <code>INSERT</code>,
     *         <code>UPDATE</code> or <code>DELETE</code> statements, or
     *         <code>0</code> for SQL statements that return nothing
     * @exception SQLException if a database access error occurs, the given SQL
     *            statement returns a <code>ResultSet</code> object, or the
     *            given constant is not one of those allowed
     * @since 1.4
     */
    public int executeUpdate(String sql, int autoGeneratedKeys) throws SQLException {
        checkIfValid();
        return pstmt.executeUpdate(sql, autoGeneratedKeys);
    }

    // JDK1.4
    /**
     * Executes the given SQL statement and signals the driver that the
     * auto-generated keys indicated in the given array should be made available
     * for retrieval. The driver will ignore the array if the SQL statement is
     * not an <code>INSERT</code> statement.
     * @param sql an SQL <code>INSERT</code>, <code>UPDATE</code> or
     *        <code>DELETE</code> statement or an SQL statement that returns
     *        nothing, such as an SQL DDL statement
     * @param columnIndexes an array of column indexes indicating the columns
     *        that should be returned from the inserted row
     * @return either the row count for <code>INSERT</code>,
     *         <code>UPDATE</code>, or <code>DELETE</code> statements, or 0
     *         for SQL statements that return nothing
     * @exception SQLException if a database access error occurs, the SQL
     *            statement returns a <code>ResultSet</code> object, or the
     *            second argument supplied to this method is not an
     *            <code>int</code> array whose elements are valid column
     *            indexes
     * @since 1.4
     */
    public int executeUpdate(String sql, int[] columnIndexes) throws SQLException {
        checkIfValid();
        return pstmt.executeUpdate(sql, columnIndexes);
    }

    // JDK1.4
    /**
     * Executes the given SQL statement and signals the driver that the
     * auto-generated keys indicated in the given array should be made available
     * for retrieval. The driver will ignore the array if the SQL statement is
     * not an <code>INSERT</code> statement.
     * @param sql an SQL <code>INSERT</code>, <code>UPDATE</code> or
     *        <code>DELETE</code> statement or an SQL statement that returns
     *        nothing
     * @param columnNames an array of the names of the columns that should be
     *        returned from the inserted row
     * @return either the row count for <code>INSERT</code>,
     *         <code>UPDATE</code>, or <code>DELETE</code> statements, or 0
     *         for SQL statements that return nothing
     * @exception SQLException if a database access error occurs, the SQL
     *            statement returns a <code>ResultSet</code> object, or the
     *            second argument supplied to this method is not a
     *            <code>String</code> array whose elements are valid column
     *            names
     * @since 1.4
     */
    public int executeUpdate(String sql, String[] columnNames) throws SQLException {
        checkIfValid();
        return pstmt.executeUpdate(sql, columnNames);
    }

    // JDK1.4
    /**
     * Retrieves any auto-generated keys created as a result of executing this
     * <code>Statement</code> object. If this <code>Statement</code> object
     * did not generate any keys, an empty <code>ResultSet</code> object is
     * returned.
     * @return a <code>ResultSet</code> object containing the auto-generated
     *         key(s) generated by the execution of this <code>Statement</code>
     *         object
     * @exception SQLException if a database access error occurs
     * @since 1.4
     */
    public ResultSet getGeneratedKeys() throws SQLException {
        checkIfValid();
        return pstmt.getGeneratedKeys();
    }

    /**
     * Retrieves a <code>ResultSetMetaData</code> object that contains
     * information about the columns of the <code>ResultSet</code> object that
     * will be returned when this <code>PreparedStatement</code> object is
     * executed.
     * <P>
     * Because a <code>PreparedStatement</code> object is precompiled, it is
     * possible to know about the <code>ResultSet</code> object that it will
     * return without having to execute it. Consequently, it is possible to
     * invoke the method <code>getMetaData</code> on a
     * <code>PreparedStatement</code> object rather than waiting to execute it
     * and then invoking the <code>ResultSet.getMetaData</code> method on the
     * <code>ResultSet</code> object that is returned.
     * <P>
     * <B>NOTE:</B> Using this method may be expensive for some drivers due to
     * the lack of underlying DBMS support.
     * @return the description of a <code>ResultSet</code> object's columns or
     *         <code>null</code> if the driver cannot return a
     *         <code>ResultSetMetaData</code> object
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public ResultSetMetaData getMetaData() throws SQLException {
        checkIfValid();
        return pstmt.getMetaData();
    }

    // JDK1.4
    /**
     * Moves to this <code>Statement</code> object's next result, deals with
     * any current <code>ResultSet</code> object(s) according to the
     * instructions specified by the given flag, and returns <code>true</code>
     * if the next result is a <code>ResultSet</code> object.
     * <P>
     * There are no more results when the following is true:
     *
     * <PRE> // stmt is a Statement object ((stmt.getMoreResults() == false) &&
     * (stmt.getUpdateCount() == -1))
     *
     * </PRE>
     *
     * @param current one of the following <code>Statement</code> constants
     *        indicating what should happen to current <code>ResultSet</code>
     *        objects obtained using the method <code>getResultSet</code>:
     *        <code>Statement.CLOSE_CURRENT_RESULT</code>,
     *        <code>Statement.KEEP_CURRENT_RESULT</code>, or
     *        <code>Statement.CLOSE_ALL_RESULTS</code>
     * @return <code>true</code> if the next result is a
     *         <code>ResultSet</code> object; <code>false</code> if it is an
     *         update count or there are no more results
     * @exception SQLException if a database access error occurs or the argument
     *            supplied is not one of the following:
     *            <code>Statement.CLOSE_CURRENT_RESULT</code>,
     *            <code>Statement.KEEP_CURRENT_RESULT</code>, or
     *            <code>Statement.CLOSE_ALL_RESULTS</code>
     * @since 1.4
     * @see #execute
     */
    public boolean getMoreResults(int current) throws SQLException {
        checkIfValid();
        return pstmt.getMoreResults(current);

    }

    // JDK1.4
    /**
     * Retrieves the number, types and properties of this
     * <code>PreparedStatement</code> object's parameters.
     * @return a <code>ParameterMetaData</code> object that contains
     *         information about the number, types and properties of this
     *         <code>PreparedStatement</code> object's parameters
     * @exception SQLException if a database access error occurs
     * @see ParameterMetaData
     * @since 1.4
     */
    public ParameterMetaData getParameterMetaData() throws SQLException {
        checkIfValid();
        return pstmt.getParameterMetaData();

    }

    // JDK1.4
    /**
     * Retrieves the result set holdability for <code>ResultSet</code> objects
     * generated by this <code>Statement</code> object.
     * @return either <code>ResultSet.HOLD_CURSORS_OVER_COMMIT</code> or
     *         <code>ResultSet.CLOSE_CURSORS_AT_COMMIT</code>
     * @exception SQLException if a database access error occurs
     * @since 1.4
     */
    public int getResultSetHoldability() throws SQLException {
        checkIfValid();
        return pstmt.getResultSetHoldability();
    }

    /**
     * Sets the designated parameter to the given <code>Array</code> object.
     * The driver converts this to an SQL <code>ARRAY</code> value when it
     * sends it to the database.
     * @param i the first parameter is 1, the second is 2, ...
     * @param x an <code>Array</code> object that maps an SQL
     *        <code>ARRAY</code> value
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public void setArray(int i, Array x) throws SQLException {
        checkIfValid();
        pstmt.setArray(i, x);
    }

    /**
     * Sets the designated parameter to the given input stream, which will have
     * the specified number of bytes. When a very large ASCII value is input to
     * a <code>LONGVARCHAR</code> parameter, it may be more practical to send
     * it via a <code>java.io.InputStream</code>. Data will be read from the
     * stream as needed until end-of-file is reached. The JDBC driver will do
     * any necessary conversion from ASCII to the database char format.
     * <P>
     * <B>Note:</B> This stream object can either be a standard Java stream
     * object or your own subclass that implements the standard interface.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the Java input stream that contains the ASCII parameter value
     * @param length the number of bytes in the stream
     * @exception SQLException if a database access error occurs
     */
    public void setAsciiStream(int parameterIndex, InputStream x, int length) throws SQLException {
        checkIfValid();
        pstmt.setAsciiStream(parameterIndex, x, length);

    }

    /**
     * Sets the designated parameter to the given
     * <code>java.math.BigDecimal</code> value. The driver converts this to an
     * SQL <code>NUMERIC</code> value when it sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setBigDecimal(int parameterIndex, BigDecimal x) throws SQLException {
        checkIfValid();
        pstmt.setBigDecimal(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given input stream, which will have
     * the specified number of bytes. When a very large binary value is input to
     * a <code>LONGVARBINARY</code> parameter, it may be more practical to
     * send it via a <code>java.io.InputStream</code> object. The data will be
     * read from the stream as needed until end-of-file is reached.
     * <P>
     * <B>Note:</B> This stream object can either be a standard Java stream
     * object or your own subclass that implements the standard interface.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the java input stream which contains the binary parameter value
     * @param length the number of bytes in the stream
     * @exception SQLException if a database access error occurs
     */
    public void setBinaryStream(int parameterIndex, InputStream x, int length) throws SQLException {
        checkIfValid();
        pstmt.setBinaryStream(parameterIndex, x, length);
    }

    /**
     * Sets the designated parameter to the given <code>Blob</code> object.
     * The driver converts this to an SQL <code>BLOB</code> value when it
     * sends it to the database.
     * @param i the first parameter is 1, the second is 2, ...
     * @param x a <code>Blob</code> object that maps an SQL <code>BLOB</code>
     *        value
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public void setBlob(int i, Blob x) throws SQLException {
        checkIfValid();
        pstmt.setBlob(i, x);
    }

    /**
     * Sets the designated parameter to the given Java <code>boolean</code>
     * value. The driver converts this to an SQL <code>BIT</code> value when
     * it sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setBoolean(int parameterIndex, boolean x) throws SQLException {
        checkIfValid();
        pstmt.setBoolean(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given Java <code>byte</code>
     * value. The driver converts this to an SQL <code>TINYINT</code> value
     * when it sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setByte(int parameterIndex, byte x) throws SQLException {
        checkIfValid();
        pstmt.setByte(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given Java array of bytes. The
     * driver converts this to an SQL <code>VARBINARY</code> or
     * <code>LONGVARBINARY</code> (depending on the argument's size relative
     * to the driver's limits on <code>VARBINARY</code> values) when it sends
     * it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setBytes(int parameterIndex, byte[] x) throws SQLException {
        checkIfValid();
        pstmt.setBytes(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given <code>Reader</code> object,
     * which is the given number of characters long. When a very large UNICODE
     * value is input to a <code>LONGVARCHAR</code> parameter, it may be more
     * practical to send it via a <code>java.io.Reader</code> object. The data
     * will be read from the stream as needed until end-of-file is reached. The
     * JDBC driver will do any necessary conversion from UNICODE to the database
     * char format.
     * <P>
     * <B>Note:</B> This stream object can either be a standard Java stream
     * object or your own subclass that implements the standard interface.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param reader the <code>java.io.Reader</code> object that contains the
     *        Unicode data
     * @param length the number of characters in the stream
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public void setCharacterStream(int parameterIndex, Reader reader, int length) throws SQLException {
        checkIfValid();
        pstmt.setCharacterStream(parameterIndex, reader, length);
    }

    /**
     * Sets the designated parameter to the given <code>Clob</code> object.
     * The driver converts this to an SQL <code>CLOB</code> value when it
     * sends it to the database.
     * @param i the first parameter is 1, the second is 2, ...
     * @param x a <code>Clob</code> object that maps an SQL <code>CLOB</code>
     *        value
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public void setClob(int i, Clob x) throws SQLException {
        checkIfValid();
        pstmt.setClob(i, x);
    }

    /**
     * Sets the designated parameter to the given <code>java.sql.Date</code>
     * value. The driver converts this to an SQL <code>DATE</code> value when
     * it sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setDate(int parameterIndex, Date x) throws SQLException {
        checkIfValid();
        pstmt.setDate(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given <code>java.sql.Date</code>
     * value, using the given <code>Calendar</code> object. The driver uses
     * the <code>Calendar</code> object to construct an SQL <code>DATE</code>
     * value, which the driver then sends to the database. With a
     * <code>Calendar</code> object, the driver can calculate the date taking
     * into account a custom timezone. If no <code>Calendar</code> object is
     * specified, the driver uses the default timezone, which is that of the
     * virtual machine running the application.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @param cal the <code>Calendar</code> object the driver will use to
     *        construct the date
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public void setDate(int parameterIndex, Date x, Calendar cal) throws SQLException {
        checkIfValid();
        pstmt.setDate(parameterIndex, x, cal);
    }

    /**
     * Sets the designated parameter to the given Java <code>double</code>
     * value. The driver converts this to an SQL <code>DOUBLE</code> value
     * when it sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setDouble(int parameterIndex, double x) throws SQLException {
        checkIfValid();
        pstmt.setDouble(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given Java <code>float</code>
     * value. The driver converts this to an SQL <code>FLOAT</code> value when
     * it sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setFloat(int parameterIndex, float x) throws SQLException {
        checkIfValid();
        pstmt.setFloat(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given Java <code>int</code> value.
     * The driver converts this to an SQL <code>INTEGER</code> value when it
     * sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setInt(int parameterIndex, int x) throws SQLException {
        checkIfValid();
        pstmt.setInt(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given Java <code>long</code>
     * value. The driver converts this to an SQL <code>BIGINT</code> value
     * when it sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setLong(int parameterIndex, long x) throws SQLException {
        checkIfValid();
        pstmt.setLong(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to SQL <code>NULL</code>.
     * <P>
     * <B>Note:</B> You must specify the parameter's SQL type.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param sqlType the SQL type code defined in <code>java.sql.Types</code>
     * @exception SQLException if a database access error occurs
     */
    public void setNull(int parameterIndex, int sqlType) throws SQLException {
        checkIfValid();
        pstmt.setNull(parameterIndex, sqlType);
    }

    /**
     * Sets the designated parameter to SQL <code>NULL</code>. This version
     * of the method <code>setNull</code> should be used for user-defined
     * types and REF type parameters. Examples of user-defined types include:
     * STRUCT, DISTINCT, JAVA_OBJECT, and named array types.
     * <P>
     * <B>Note:</B> To be portable, applications must give the SQL type code
     * and the fully-qualified SQL type name when specifying a NULL user-defined
     * or REF parameter. In the case of a user-defined type the name is the type
     * name of the parameter itself. For a REF parameter, the name is the type
     * name of the referenced type. If a JDBC driver does not need the type code
     * or type name information, it may ignore it. Although it is intended for
     * user-defined and Ref parameters, this method may be used to set a null
     * parameter of any JDBC type. If the parameter does not have a user-defined
     * or REF type, the given typeName is ignored.
     * @param paramIndex the first parameter is 1, the second is 2, ...
     * @param sqlType a value from <code>java.sql.Types</code>
     * @param typeName the fully-qualified name of an SQL user-defined type;
     *        ignored if the parameter is not a user-defined type or REF
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public void setNull(int paramIndex, int sqlType, String typeName) throws SQLException {
        checkIfValid();
        pstmt.setNull(paramIndex, sqlType, typeName);
    }

    /**
     * <p>
     * Sets the value of the designated parameter using the given object. The
     * second parameter must be of type <code>Object</code>; therefore, the
     * <code>java.lang</code> equivalent objects should be used for built-in
     * types.
     * <p>
     * The JDBC specification specifies a standard mapping from Java
     * <code>Object</code> types to SQL types. The given argument will be
     * converted to the corresponding SQL type before being sent to the
     * database.
     * <p>
     * Note that this method may be used to pass datatabase- specific abstract
     * data types, by using a driver-specific Java type. If the object is of a
     * class implementing the interface <code>SQLData</code>, the JDBC driver
     * should call the method <code>SQLData.writeSQL</code> to write it to the
     * SQL data stream. If, on the other hand, the object is of a class
     * implementing <code>Ref</code>, <code>Blob</code>, <code>Clob</code>,
     * <code>Struct</code>, or <code>Array</code>, the driver should pass
     * it to the database as a value of the corresponding SQL type.
     * <P>
     * This method throws an exception if there is an ambiguity, for example, if
     * the object is of a class implementing more than one of the interfaces
     * named above.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the object containing the input parameter value
     * @exception SQLException if a database access error occurs or the type of
     *            the given object is ambiguous
     */
    public void setObject(int parameterIndex, Object x) throws SQLException {
        checkIfValid();
        pstmt.setObject(parameterIndex, x);
    }

    /**
     * Sets the value of the designated parameter with the given object. This
     * method is like the method <code>setObject</code> above, except that it
     * assumes a scale of zero.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the object containing the input parameter value
     * @param targetSqlType the SQL type (as defined in java.sql.Types) to be
     *        sent to the database
     * @exception SQLException if a database access error occurs
     */
    public void setObject(int parameterIndex, Object x, int targetSqlType) throws SQLException {
        checkIfValid();
        pstmt.setObject(parameterIndex, x, targetSqlType);
    }

    /**
     * <p>
     * Sets the value of the designated parameter with the given object. The
     * second argument must be an object type; for integral values, the
     * <code>java.lang</code> equivalent objects should be used.
     * <p>
     * The given Java object will be converted to the given targetSqlType before
     * being sent to the database. If the object has a custom mapping (is of a
     * class implementing the interface <code>SQLData</code>), the JDBC
     * driver should call the method <code>SQLData.writeSQL</code> to write it
     * to the SQL data stream. If, on the other hand, the object is of a class
     * implementing <code>Ref</code>, <code>Blob</code>, <code>Clob</code>,
     * <code>Struct</code>, or <code>Array</code>, the driver should pass
     * it to the database as a value of the corresponding SQL type.
     * <p>
     * Note that this method may be used to pass database-specific abstract data
     * types.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the object containing the input parameter value
     * @param targetSqlType the SQL type (as defined in java.sql.Types) to be
     *        sent to the database. The scale argument may further qualify this
     *        type.
     * @param scale for java.sql.Types.DECIMAL or java.sql.Types.NUMERIC types,
     *        this is the number of digits after the decimal point. For all
     *        other types, this value will be ignored.
     * @exception SQLException if a database access error occurs
     * @see Types
     */
    public void setObject(int parameterIndex, Object x, int targetSqlType, int scale) throws SQLException {
        checkIfValid();
        pstmt.setObject(parameterIndex, x, targetSqlType, scale);
    }

    /**
     * Sets the designated parameter to the given
     * <code>REF(&lt;structured-type&gt;)</code> value. The driver converts
     * this to an SQL <code>REF</code> value when it sends it to the database.
     * @param i the first parameter is 1, the second is 2, ...
     * @param x an SQL <code>REF</code> value
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public void setRef(int i, Ref x) throws SQLException {
        checkIfValid();
        pstmt.setRef(i, x);
    }

    /**
     * Sets the designated parameter to the given Java <code>short</code>
     * value. The driver converts this to an SQL <code>SMALLINT</code> value
     * when it sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setShort(int parameterIndex, short x) throws SQLException {
        checkIfValid();
        pstmt.setShort(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given Java <code>String</code>
     * value. The driver converts this to an SQL <code>VARCHAR</code> or
     * <code>LONGVARCHAR</code> value (depending on the argument's size
     * relative to the driver's limits on <code>VARCHAR</code> values) when it
     * sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setString(int parameterIndex, String x) throws SQLException {
        checkIfValid();
        pstmt.setString(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given <code>java.sql.Time</code>
     * value. The driver converts this to an SQL <code>TIME</code> value when
     * it sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setTime(int parameterIndex, Time x) throws SQLException {
        checkIfValid();
        pstmt.setTime(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given <code>java.sql.Time</code>
     * value, using the given <code>Calendar</code> object. The driver uses
     * the <code>Calendar</code> object to construct an SQL <code>TIME</code>
     * value, which the driver then sends to the database. With a
     * <code>Calendar</code> object, the driver can calculate the time taking
     * into account a custom timezone. If no <code>Calendar</code> object is
     * specified, the driver uses the default timezone, which is that of the
     * virtual machine running the application.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @param cal the <code>Calendar</code> object the driver will use to
     *        construct the time
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public void setTime(int parameterIndex, Time x, Calendar cal) throws SQLException {
        checkIfValid();
        pstmt.setTime(parameterIndex, x, cal);
    }

    /**
     * Sets the designated parameter to the given
     * <code>java.sql.Timestamp</code> value. The driver converts this to an
     * SQL <code>TIMESTAMP</code> value when it sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @exception SQLException if a database access error occurs
     */
    public void setTimestamp(int parameterIndex, Timestamp x) throws SQLException {
        checkIfValid();
        pstmt.setTimestamp(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given
     * <code>java.sql.Timestamp</code> value, using the given
     * <code>Calendar</code> object. The driver uses the <code>Calendar</code>
     * object to construct an SQL <code>TIMESTAMP</code> value, which the
     * driver then sends to the database. With a <code>Calendar</code> object,
     * the driver can calculate the timestamp taking into account a custom
     * timezone. If no <code>Calendar</code> object is specified, the driver
     * uses the default timezone, which is that of the virtual machine running
     * the application.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @param cal the <code>Calendar</code> object the driver will use to
     *        construct the timestamp
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public void setTimestamp(int parameterIndex, Timestamp x, Calendar cal) throws SQLException {
        checkIfValid();
        pstmt.setTimestamp(parameterIndex, x, cal);
    }

    /**
     * Sets the designated parameter to the given input stream, which will have
     * the specified number of bytes. A Unicode character has two bytes, with
     * the first byte being the high byte, and the second being the low byte.
     * When a very large Unicode value is input to a <code>LONGVARCHAR</code>
     * parameter, it may be more practical to send it via a
     * <code>java.io.InputStream</code> object. The data will be read from the
     * stream as needed until end-of-file is reached. The JDBC driver will do
     * any necessary conversion from Unicode to the database char format.
     * <P>
     * <B>Note:</B> This stream object can either be a standard Java stream
     * object or your own subclass that implements the standard interface.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x a <code>java.io.InputStream</code> object that contains the
     *        Unicode parameter value as two-byte Unicode characters
     * @param length the number of bytes in the stream
     * @exception SQLException if a database access error occurs
     * @deprecated
     */
    public void setUnicodeStream(int parameterIndex, InputStream x, int length) throws SQLException {
        checkIfValid();
        pstmt.setUnicodeStream(parameterIndex, x, length);
    }

    // Statement interface

    /**
     * Adds the given SQL command to the current list of commmands for this
     * <code>Statement</code> object. The commands in this list can be
     * executed as a batch by calling the method <code>executeBatch</code>.
     * <P>
     * <B>NOTE:</B> This method is optional.
     * @param s typically this is a static SQL <code>INSERT</code> or
     *        <code>UPDATE</code> statement
     * @exception SQLException if a database access error occurs, or the driver
     *            does not support batch updates
     * @see #executeBatch
     * @since 1.2
     */
    public void addBatch(String s) throws SQLException {
        checkIfValid();
        pstmt.addBatch(s);
    }

    /**
     * Cancels this <code>Statement</code> object if both the DBMS and driver
     * support aborting an SQL statement. This method can be used by one thread
     * to cancel a statement that is being executed by another thread.
     * @exception SQLException if a database access error occurs
     */
    public void cancel() throws SQLException {
        checkIfValid();
        pstmt.cancel();
    }

    /**
     * Empties this <code>Statement</code> object's current list of SQL
     * commands.
     * <P>
     * <B>NOTE:</B> This method is optional.
     * @exception SQLException if a database access error occurs or the driver
     *            does not support batch updates
     * @see #addBatch
     * @since 1.2
     */
    public void clearBatch() throws SQLException {
        checkIfValid();
        pstmt.clearBatch();
    }

    /**
     * Clears all the warnings reported on this <code>Statement</code> object.
     * After a call to this method, the method <code>getWarnings</code> will
     * return <code>null</code> until a new warning is reported for this
     * <code>Statement</code> object.
     * @exception SQLException if a database access error occurs
     */
    public void clearWarnings() throws SQLException {
        checkIfValid();
        pstmt.clearWarnings();
    }

    /**
     * Releases this <code>Statement</code> object's database and JDBC
     * resources immediately instead of waiting for this to happen when it is
     * automatically closed. It is generally good practice to release resources
     * as soon as you are finished with them to avoid tying up database
     * resources.
     * <P>
     * Calling the method <code>close</code> on a <code>Statement</code>
     * object that is already closed has no effect.
     * <P>
     * <B>Note:</B> A <code>Statement</code> object is automatically closed
     * when it is garbage collected. When a <code>Statement</code> object is
     * closed, its current <code>ResultSet</code> object, if one exists, is
     * also closed.
     * @exception SQLException if a database access error occurs
     */
    public void close() throws SQLException {
        if (isDebugLogging) {
            trace.log(BasicLevel.DEBUG, "" + this);
        }
        closed = true;
    }

    /**
     * Executes the given SQL statement, which may return multiple results. In
     * some (uncommon) situations, a single SQL statement may return multiple
     * result sets and/or update counts. Normally you can ignore this unless you
     * are (1) executing a stored procedure that you know may return multiple
     * results or (2) you are dynamically executing an unknown SQL string.
     * <P>
     * The <code>execute</code> method executes an SQL statement and indicates
     * the form of the first result. You must then use the methods
     * <code>getResultSet</code> or <code>getUpdateCount</code> to retrieve
     * the result, and <code>getMoreResults</code> to move to any subsequent
     * result(s).
     * @param s any SQL statement
     * @return <code>true</code> if the first result is a
     *         <code>ResultSet</code> object; <code>false</code> if it is an
     *         update count or there are no results
     * @exception SQLException if a database access error occurs
     * @see #getResultSet
     * @see #getUpdateCount
     * @see #getMoreResults
     */
    public boolean execute(String s) throws SQLException {
        checkIfValid();
        return pstmt.execute(s);
    }

    /**
     * Submits a batch of commands to the database for execution and if all
     * commands execute successfully, returns an array of update counts. The
     * <code>int</code> elements of the array that is returned are ordered to
     * correspond to the commands in the batch, which are ordered according to
     * the order in which they were added to the batch. The elements in the
     * array returned by the method <code>executeBatch</code> may be one of
     * the following:
     * <OL>
     * <LI>A number greater than or equal to zero -- indicates that the command
     * was processed successfully and is an update count giving the number of
     * rows in the database that were affected by the command's execution
     * <LI>A value of <code>SUCCESS_NO_INFO</code> -- indicates that the
     * command was processed successfully but that the number of rows affected
     * is unknown
     * <P>
     * If one of the commands in a batch update fails to execute properly, this
     * method throws a <code>BatchUpdateException</code>, and a JDBC driver
     * may or may not continue to process the remaining commands in the batch.
     * However, the driver's behavior must be consistent with a particular DBMS,
     * either always continuing to process commands or never continuing to
     * process commands. If the driver continues processing after a failure, the
     * array returned by the method
     * <code>BatchUpdateException.getUpdateCounts</code> will contain as many
     * elements as there are commands in the batch, and at least one of the
     * elements will be the following:
     * <P>
     * <LI>A value of <code>EXECUTE_FAILED</code> -- indicates that the
     * command failed to execute successfully and occurs only if a driver
     * continues to process commands after a command fails
     * </OL>
     * <P>
     * A driver is not required to implement this method. The possible
     * implementations and return values have been modified in the Java 2 SDK,
     * Standard Edition, version 1.3 to accommodate the option of continuing to
     * proccess commands in a batch update after a
     * <code>BatchUpdateException</code> obejct has been thrown.
     * @return an array of update counts containing one element for each command
     *         in the batch. The elements of the array are ordered according to
     *         the order in which commands were added to the batch.
     * @exception SQLException if a database access error occurs or the driver
     *            does not support batch statements. Throws
     *            {@link BatchUpdateException} (a subclass of
     *            <code>SQLException</code>) if one of the commands sent to
     *            the database fails to execute properly or attempts to return a
     *            result set.
     * @since 1.3
     */
    public int[] executeBatch() throws SQLException {
        checkIfValid();
        return pstmt.executeBatch();
    }

    /**
     * Executes the given SQL statement, which returns a single
     * <code>ResultSet</code> object.
     * @param s an SQL statement to be sent to the database, typically a static
     *        SQL <code>SELECT</code> statement
     * @return a <code>ResultSet</code> object that contains the data produced
     *         by the given query; never <code>null</code>
     * @exception SQLException if a database access error occurs or the given
     *            SQL statement produces anything other than a single
     *            <code>ResultSet</code> object
     */
    public ResultSet executeQuery(String s) throws SQLException {
        checkIfValid();
        return pstmt.executeQuery(s);
    }

    /**
     * Executes the given SQL statement, which may be an <code>INSERT</code>,
     * <code>UPDATE</code>, or <code>DELETE</code> statement or an SQL
     * statement that returns nothing, such as an SQL DDL statement.
     * @param s an SQL <code>INSERT</code>, <code>UPDATE</code> or
     *        <code>DELETE</code> statement or an SQL statement that returns
     *        nothing
     * @return either the row count for <code>INSERT</code>,
     *         <code>UPDATE</code> or <code>DELETE</code> statements, or
     *         <code>0</code> for SQL statements that return nothing
     * @exception SQLException if a database access error occurs or the given
     *            SQL statement produces a <code>ResultSet</code> object
     */
    public int executeUpdate(String s) throws SQLException {
        checkIfValid();
        return pstmt.executeUpdate(s);
    }

    /**
     * Retrieves the <code>Connection</code> object that produced this
     * <code>Statement</code> object.
     * @return the connection that produced this statement
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public Connection getConnection() throws SQLException {
        checkIfValid();
        return pstmt.getConnection();
    }

    /**
     * Retrieves the direction for fetching rows from database tables that is
     * the default for result sets generated from this <code>Statement</code>
     * object. If this <code>Statement</code> object has not set a fetch
     * direction by calling the method <code>setFetchDirection</code>, the
     * return value is implementation-specific.
     * @return the default fetch direction for result sets generated from this
     *         <code>Statement</code> object
     * @exception SQLException if a database access error occurs
     * @since 1.2
     * @see #setFetchDirection
     */
    public int getFetchDirection() throws SQLException {
        checkIfValid();
        return pstmt.getFetchDirection();
    }

    /**
     * Retrieves the number of result set rows that is the default fetch size
     * for <code>ResultSet</code> objects generated from this
     * <code>Statement</code> object. If this <code>Statement</code> object
     * has not set a fetch size by calling the method <code>setFetchSize</code>,
     * the return value is implementation-specific.
     * @return the default fetch size for result sets generated from this
     *         <code>Statement</code> object
     * @exception SQLException if a database access error occurs
     * @since 1.2
     * @see #setFetchSize
     */
    public int getFetchSize() throws SQLException {
        checkIfValid();
        return pstmt.getFetchSize();
    }

    /**
     * Retrieves the maximum number of bytes that can be returned for character
     * and binary column values in a <code>ResultSet</code> object produced by
     * this <code>Statement</code> object. This limit applies only to
     * <code>BINARY</code>, <code>VARBINARY</code>,
     * <code>LONGVARBINARY</code>, <code>CHAR</code>, <code>VARCHAR</code>,
     * and <code>LONGVARCHAR</code> columns. If the limit is exceeded, the
     * excess data is silently discarded.
     * @return the current column size limit for columns storing character and
     *         binary values; zero means there is no limit
     * @exception SQLException if a database access error occurs
     * @see #setMaxFieldSize
     */
    public int getMaxFieldSize() throws SQLException {
        checkIfValid();
        return pstmt.getMaxFieldSize();
    }

    /**
     * Retrieves the maximum number of rows that a <code>ResultSet</code>
     * object produced by this <code>Statement</code> object can contain. If
     * this limit is exceeded, the excess rows are silently dropped.
     * @return the current maximum number of rows for a <code>ResultSet</code>
     *         object produced by this <code>Statement</code> object; zero
     *         means there is no limit
     * @exception SQLException if a database access error occurs
     * @see #setMaxRows
     */
    public int getMaxRows() throws SQLException {
        checkIfValid();
        return pstmt.getMaxRows();
    }

    /**
     * Moves to this <code>Statement</code> object's next result, returns
     * <code>true</code> if it is a <code>ResultSet</code> object, and
     * implicitly closes any current <code>ResultSet</code> object(s) obtained
     * with the method <code>getResultSet</code>.
     * <P>
     * There are no more results when the following is true:
     *
     * <PRE> // stmt is a Statement object ((stmt.getMoreResults() == false) &&
     * (stmt.getUpdateCount() == -1))
     *
     * </PRE>
     *
     * @return <code>true</code> if the next result is a
     *         <code>ResultSet</code> object; <code>false</code> if it is an
     *         update count or there are no more results
     * @exception SQLException if a database access error occurs
     * @see #execute
     */
    public boolean getMoreResults() throws SQLException {
        checkIfValid();
        return pstmt.getMoreResults();
    }

    /**
     * Retrieves the number of seconds the driver will wait for a
     * <code>Statement</code> object to execute. If the limit is exceeded, a
     * <code>SQLException</code> is thrown.
     * @return the current query timeout limit in seconds; zero means there is
     *         no limit
     * @exception SQLException if a database access error occurs
     * @see #setQueryTimeout
     */
    public int getQueryTimeout() throws SQLException {
        checkIfValid();
        return pstmt.getQueryTimeout();
    }

    /**
     * Retrieves the current result as a <code>ResultSet</code> object. This
     * method should be called only once per result.
     * @return the current result as a <code>ResultSet</code> object or
     *         <code>null</code> if the result is an update count or there are
     *         no more results
     * @exception SQLException if a database access error occurs
     * @see #execute
     */
    public ResultSet getResultSet() throws SQLException {
        checkIfValid();
        return pstmt.getResultSet();
    }

    /**
     * Retrieves the result set concurrency for <code>ResultSet</code> objects
     * generated by this <code>Statement</code> object.
     * @return either <code>ResultSet.CONCUR_READ_ONLY</code> or
     *         <code>ResultSet.CONCUR_UPDATABLE</code>
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public int getResultSetConcurrency() throws SQLException {
        checkIfValid();
        return pstmt.getResultSetConcurrency();
    }

    /**
     * Retrieves the result set type for <code>ResultSet</code> objects
     * generated by this <code>Statement</code> object.
     * @return one of <code>ResultSet.TYPE_FORWARD_ONLY</code>,
     *         <code>ResultSet.TYPE_SCROLL_INSENSITIVE</code>, or
     *         <code>ResultSet.TYPE_SCROLL_SENSITIVE</code>
     * @exception SQLException if a database access error occurs
     * @since 1.2
     */
    public int getResultSetType() throws SQLException {
        checkIfValid();
        return pstmt.getResultSetType();
    }

    /**
     * Retrieves the current result as an update count; if the result is a
     * <code>ResultSet</code> object or there are no more results, -1 is
     * returned. This method should be called only once per result.
     * @return the current result as an update count; -1 if the current result
     *         is a <code>ResultSet</code> object or there are no more results
     * @exception SQLException if a database access error occurs
     * @see #execute
     */
    public int getUpdateCount() throws SQLException {
        checkIfValid();
        return pstmt.getUpdateCount();
    }

    /**
     * Retrieves the first warning reported by calls on this
     * <code>Statement</code> object. Subsequent <code>Statement</code>
     * object warnings will be chained to this <code>SQLWarning</code> object.
     * <p>
     * The warning chain is automatically cleared each time a statement is
     * (re)executed. This method may not be called on a closed
     * <code>Statement</code> object; doing so will cause an
     * <code>SQLException</code> to be thrown.
     * <P>
     * <B>Note:</B> If you are processing a <code>ResultSet</code> object,
     * any warnings associated with reads on that <code>ResultSet</code>
     * object will be chained on it rather than on the <code>Statement</code>
     * object that produced it.
     * @return the first <code>SQLWarning</code> object or <code>null</code>
     *         if there are no warnings
     * @exception SQLException if a database access error occurs or this method
     *            is called on a closed statement
     */
    public SQLWarning getWarnings() throws SQLException {
        checkIfValid();
        return pstmt.getWarnings();
    }

    /**
     * Sets the SQL cursor name to the given <code>String</code>, which will
     * be used by subsequent <code>Statement</code> object
     * <code>execute</code> methods. This name can then be used in SQL
     * positioned update or delete statements to identify the current row in the
     * <code>ResultSet</code> object generated by this statement. If the
     * database does not support positioned update/delete, this method is a
     * noop. To insure that a cursor has the proper isolation level to support
     * updates, the cursor's <code>SELECT</code> statement should have the
     * form <code>SELECT FOR UPDATE</code>. If <code>FOR UPDATE</code> is
     * not present, positioned updates may fail.
     * <P>
     * <B>Note:</B> By definition, the execution of positioned updates and
     * deletes must be done by a different <code>Statement</code> object than
     * the one that generated the <code>ResultSet</code> object being used for
     * positioning. Also, cursor names must be unique within a connection.
     * @param name the new cursor name, which must be unique within a connection
     * @exception SQLException if a database access error occurs
     */
    public void setCursorName(String name) throws SQLException {
        checkIfValid();
        pstmt.setCursorName(name);
    }

    /**
     * Sets escape processing on or off. If escape scanning is on (the default),
     * the driver will do escape substitution before sending the SQL statement
     * to the database. Note: Since prepared statements have usually been parsed
     * prior to making this call, disabling escape processing for
     * <code>PreparedStatements</code> objects will have no effect.
     * @param enable <code>true</code> to enable escape processing;
     *        <code>false</code> to disable it
     * @exception SQLException if a database access error occurs
     */
    public void setEscapeProcessing(boolean enable) throws SQLException {
        checkIfValid();
        // mark this method as called (even if it doesn't succeed)
        setEscapeProcessingCalled = true;
        pstmt.setEscapeProcessing(enable);
    }

    /**
     * Gives the driver a hint as to the direction in which rows will be
     * processed in <code>ResultSet</code> objects created using this
     * <code>Statement</code> object. The default value is
     * <code>ResultSet.FETCH_FORWARD</code>.
     * <P>
     * Note that this method sets the default fetch direction for result sets
     * generated by this <code>Statement</code> object. Each result set has
     * its own methods for getting and setting its own fetch direction.
     * @param direction the initial direction for processing rows
     * @exception SQLException if a database access error occurs or the given
     *            direction is not one of <code>ResultSet.FETCH_FORWARD</code>,
     *            <code>ResultSet.FETCH_REVERSE</code>, or
     *            <code>ResultSet.FETCH_UNKNOWN</code>
     * @since 1.2
     * @see #getFetchDirection
     */
    public void setFetchDirection(int direction) throws SQLException {
        checkIfValid();
        // mark this method as called (even if it doesn't succeed)
        setFetchDirectionCalled = true;
        pstmt.setFetchDirection(direction);
    }

    /**
     * Gives the JDBC driver a hint as to the number of rows that should be
     * fetched from the database when more rows are needed. The number of rows
     * specified affects only result sets created using this statement. If the
     * value specified is zero, then the hint is ignored. The default value is
     * zero.
     * @param rows the number of rows to fetch
     * @exception SQLException if a database access error occurs, or the
     *            condition 0 <= <code>rows</code> <=
     *            <code>this.getMaxRows()</code> is not satisfied.
     * @since 1.2
     * @see #getFetchSize
     */
    public void setFetchSize(int rows) throws SQLException {
        checkIfValid();
        pstmt.setFetchSize(rows);
    }

    /**
     * Sets the limit for the maximum number of bytes in a
     * <code>ResultSet</code> column storing character or binary values to the
     * given number of bytes. This limit applies only to <code>BINARY</code>,
     * <code>VARBINARY</code>, <code>LONGVARBINARY</code>,
     * <code>CHAR</code>, <code>VARCHAR</code>, and
     * <code>LONGVARCHAR</code> fields. If the limit is exceeded, the excess
     * data is silently discarded. For maximum portability, use values greater
     * than 256.
     * @param max the new column size limit in bytes; zero means there is no
     *        limit
     * @exception SQLException if a database access error occurs or the
     *            condition max >= 0 is not satisfied
     * @see #getMaxFieldSize
     */
    public void setMaxFieldSize(int max) throws SQLException {
        checkIfValid();
        // mark this method as called (even if it doesn't succeed)
        setMaxFieldSizeCalled = true;
        pstmt.setMaxFieldSize(max);
    }

    /**
     * Sets the limit for the maximum number of rows that any
     * <code>ResultSet</code> object can contain to the given number. If the
     * limit is exceeded, the excess rows are silently dropped.
     * @param max the new max rows limit; zero means there is no limit
     * @exception SQLException if a database access error occurs or the
     *            condition max >= 0 is not satisfied
     * @see #getMaxRows
     */
    public void setMaxRows(int max) throws SQLException {
        checkIfValid();
        pstmt.setMaxRows(max);
    }

    /**
     * Sets the number of seconds the driver will wait for a
     * <code>Statement</code> object to execute to the given number of
     * seconds. If the limit is exceeded, an <code>SQLException</code> is
     * thrown.
     * @param seconds the new query timeout limit in seconds; zero means there
     *        is no limit
     * @exception SQLException if a database access error occurs or the
     *            condition seconds >= 0 is not satisfied
     * @see #getQueryTimeout
     */
    public void setQueryTimeout(int seconds) throws SQLException {
        checkIfValid();
        pstmt.setQueryTimeout(seconds);
    }

    // JDK1.4
    /**
     * Sets the designated parameter to the given <code>java.net.URL</code>
     * value. The driver converts this to an SQL <code>DATALINK</code> value
     * when it sends it to the database.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the <code>java.net.URL</code> object to be set
     * @exception SQLException if a database access error occurs
     * @since 1.4
     */
    public void setURL(int parameterIndex, URL x) throws SQLException {
        checkIfValid();
        pstmt.setURL(parameterIndex, x);
    }

    /**
     * @return hashcode of the object
     */
    public int hashCode() {
        return hashCode;
    }

    /**
     * @return true if statement has been closed
     */
    public boolean isClosed() {
        return closed;
    }



    /**
     * Sets the designated parameter to the given <code>java.sql.RowId</code> object. The driver converts this to a SQL
     * <code>ROWID</code> value when it sends it to the database
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the parameter value
     * @throws SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if a database access
     * error occurs or this method is called on a closed <code>PreparedStatement</code>
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setRowId(int parameterIndex, RowId x) throws SQLException {
        checkIfValid();
        pstmt.setRowId(parameterIndex, x);
    }

    /**
     * Sets the designated paramter to the given <code>String</code> object. The driver converts this to a SQL <code>NCHAR</code>
     * or <code>NVARCHAR</code> or <code>LONGNVARCHAR</code> value (depending on the argument's size relative to the driver's
     * limits on <code>NVARCHAR</code> values) when it sends it to the database.
     * @param parameterIndex of the first parameter is 1, the second is 2, ...
     * @param value the parameter value
     * @throws SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if the driver does
     * not support national character sets; if the driver can detect that a data conversion error could occur; if a database
     * access error occurs; or this method is called on a closed <code>PreparedStatement</code>
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setNString(int parameterIndex, String value) throws SQLException {
        checkIfValid();
        pstmt.setNString(parameterIndex, value);
    }

    /**
     * Sets the designated parameter to a <code>Reader</code> object. The <code>Reader</code> reads the data till end-of-file is
     * reached. The driver does the necessary conversion from Java character format to the national character set in the database.
     * @param parameterIndex of the first parameter is 1, the second is 2, ...
     * @param value the parameter value
     * @param length the number of characters in the parameter data.
     * @throws SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if the driver does
     * not support national character sets; if the driver can detect that a data conversion error could occur; if a database
     * access error occurs; or this method is called on a closed <code>PreparedStatement</code>
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setNCharacterStream(int parameterIndex, Reader value, long length) throws SQLException {
        checkIfValid();
        pstmt.setNCharacterStream(parameterIndex, value, length);
    }

    /**
     * Sets the designated parameter to a <code>java.sql.NClob</code> object. The driver converts this to a SQL <code>NCLOB</code>
     * value when it sends it to the database.
     * @param parameterIndex of the first parameter is 1, the second is 2, ...
     * @param value the parameter value
     * @throws SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if the driver does
     * not support national character sets; if the driver can detect that a data conversion error could occur; if a database
     * access error occurs; or this method is called on a closed <code>PreparedStatement</code>
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setNClob(int parameterIndex, NClob value) throws SQLException {
        checkIfValid();
        pstmt.setNClob(parameterIndex, value);
    }

    /**
     * Sets the designated parameter to a <code>Reader</code> object. The reader must contain the number of characters specified
     * by length otherwise a <code>SQLException</code> will be generated when the <code>PreparedStatement</code> is executed. This
     * method differs from the <code>setCharacterStream (int, Reader, int)</code> method because it informs the driver that the
     * parameter value should be sent to the server as a <code>CLOB</code>. When the <code>setCharacterStream</code> method is
     * used, the driver may have to do extra work to determine whether the parameter data should be sent to the server as a
     * <code>LONGVARCHAR</code> or a <code>CLOB</code>
     * @param parameterIndex index of the first parameter is 1, the second is 2, ...
     * @param reader An object that contains the data to set the parameter value to.
     * @param length the number of characters in the parameter data.
     * @throws SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if a database access
     * error occurs; this method is called on a closed <code>PreparedStatement</code> or if the length specified is less than
     * zero.
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setClob(int parameterIndex, Reader reader, long length) throws SQLException {
        checkIfValid();
        pstmt.setClob(parameterIndex, reader, length);
    }

    /**
     * Sets the designated parameter to a <code>InputStream</code> object. The inputstream must contain the number of characters
     * specified by length otherwise a <code>SQLException</code> will be generated when the <code>PreparedStatement</code> is
     * executed. This method differs from the <code>setBinaryStream (int, InputStream, int)</code> method because it informs the
     * driver that the parameter value should be sent to the server as a <code>BLOB</code>. When the <code>setBinaryStream</code>
     * method is used, the driver may have to do extra work to determine whether the parameter data should be sent to the server
     * as a <code>LONGVARBINARY</code> or a <code>BLOB</code>
     * @param parameterIndex index of the first parameter is 1, the second is 2, ...
     * @param inputStream An object that contains the data to set the parameter value to.
     * @param length the number of bytes in the parameter data.
     * @throws SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if a database access
     * error occurs; this method is called on a closed <code>PreparedStatement</code>; if the length specified is less than zero
     * or if the number of bytes in the inputstream does not match the specfied length.
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setBlob(int parameterIndex, InputStream inputStream, long length) throws SQLException {
        checkIfValid();
        pstmt.setBlob(parameterIndex, inputStream, length);
    }

    /**
     * Sets the designated parameter to a <code>Reader</code> object. The reader must contain the number of characters specified
     * by length otherwise a <code>SQLException</code> will be generated when the <code>PreparedStatement</code> is executed. This
     * method differs from the <code>setCharacterStream (int, Reader, int)</code> method because it informs the driver that the
     * parameter value should be sent to the server as a <code>NCLOB</code>. When the <code>setCharacterStream</code> method is
     * used, the driver may have to do extra work to determine whether the parameter data should be sent to the server as a
     * <code>LONGNVARCHAR</code> or a <code>NCLOB</code>
     * @param parameterIndex index of the first parameter is 1, the second is 2, ...
     * @param reader An object that contains the data to set the parameter value to.
     * @param length the number of characters in the parameter data.
     * @throws SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if the length
     * specified is less than zero; if the driver does not support national character sets; if the driver can detect that a data
     * conversion error could occur; if a database access error occurs or this method is called on a closed
     * <code>PreparedStatement</code>
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setNClob(int parameterIndex, Reader reader, long length) throws SQLException {
        checkIfValid();
        pstmt.setNClob(parameterIndex, reader, length);
    }

    /**
     * Sets the designated parameter to the given <code>java.sql.SQLXML</code> object. The driver converts this to an SQL
     * <code>XML</code> value when it sends it to the database.
     * <p>
     * @param parameterIndex index of the first parameter is 1, the second is 2, ...
     * @param xmlObject a <code>SQLXML</code> object that maps an SQL <code>XML</code> value
     * @throws SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if a database access
     * error occurs; this method is called on a closed <code>PreparedStatement</code> or the
     * <code>java.xml.transform.Result</code>, <code>Writer</code> or <code>OutputStream</code> has not been closed for the
     * <code>SQLXML</code> object
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setSQLXML(int parameterIndex, SQLXML xmlObject) throws SQLException {
        checkIfValid();
        pstmt.setSQLXML(parameterIndex, xmlObject);
    }



    /**
     * Sets the designated parameter to the given input stream, which will have the specified number of bytes. When a very large
     * ASCII value is input to a <code>LONGVARCHAR</code> parameter, it may be more practical to send it via a
     * <code>java.io.InputStream</code>. Data will be read from the stream as needed until end-of-file is reached. The JDBC driver
     * will do any necessary conversion from ASCII to the database char format.
     * <P>
     * <B>Note:</B> This stream object can either be a standard Java stream object or your own subclass that implements the
     * standard interface.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the Java input stream that contains the ASCII parameter value
     * @param length the number of bytes in the stream
     * @exception SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if a database
     * access error occurs or this method is called on a closed <code>PreparedStatement</code>
     * @since 1.6
     */
    public void setAsciiStream(int parameterIndex, java.io.InputStream x, long length) throws SQLException {
        checkIfValid();
        pstmt.setAsciiStream(parameterIndex, x, length);
    }


    /**
     * Sets the designated parameter to the given input stream, which will have the specified number of bytes. When a very large
     * binary value is input to a <code>LONGVARBINARY</code> parameter, it may be more practical to send it via a
     * <code>java.io.InputStream</code> object. The data will be read from the stream as needed until end-of-file is reached.
     * <P>
     * <B>Note:</B> This stream object can either be a standard Java stream object or your own subclass that implements the
     * standard interface.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the java input stream which contains the binary parameter value
     * @param length the number of bytes in the stream
     * @exception SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if a database
     * access error occurs or this method is called on a closed <code>PreparedStatement</code>
     * @since 1.6
     */
    public void setBinaryStream(int parameterIndex, java.io.InputStream x, long length) throws SQLException {
        checkIfValid();
        pstmt.setBinaryStream(parameterIndex, x, length);
    }

    /**
     * Sets the designated parameter to the given <code>Reader</code> object, which is the given number of characters long. When a
     * very large UNICODE value is input to a <code>LONGVARCHAR</code> parameter, it may be more practical to send it via a
     * <code>java.io.Reader</code> object. The data will be read from the stream as needed until end-of-file is reached. The JDBC
     * driver will do any necessary conversion from UNICODE to the database char format.
     * <P>
     * <B>Note:</B> This stream object can either be a standard Java stream object or your own subclass that implements the
     * standard interface.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param reader the <code>java.io.Reader</code> object that contains the Unicode data
     * @param length the number of characters in the stream
     * @exception SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if a database
     * access error occurs or this method is called on a closed <code>PreparedStatement</code>
     * @since 1.6
     */
    public void setCharacterStream(int parameterIndex, java.io.Reader reader, long length) throws SQLException {
        checkIfValid();
        pstmt.setCharacterStream(parameterIndex, reader, length);
    }

    // -----
    /**
     * Sets the designated parameter to the given input stream. When a very large ASCII value is input to a
     * <code>LONGVARCHAR</code> parameter, it may be more practical to send it via a <code>java.io.InputStream</code>. Data will
     * be read from the stream as needed until end-of-file is reached. The JDBC driver will do any necessary conversion from ASCII
     * to the database char format.
     * <P>
     * <B>Note:</B> This stream object can either be a standard Java stream object or your own subclass that implements the
     * standard interface.
     * <P>
     * <B>Note:</B> Consult your JDBC driver documentation to determine if it might be more efficient to use a version of
     * <code>setAsciiStream</code> which takes a length parameter.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the Java input stream that contains the ASCII parameter value
     * @exception SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if a database
     * access error occurs or this method is called on a closed <code>PreparedStatement</code>
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setAsciiStream(int parameterIndex, java.io.InputStream x) throws SQLException {
        checkIfValid();
        pstmt.setAsciiStream(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given input stream. When a very large binary value is input to a
     * <code>LONGVARBINARY</code> parameter, it may be more practical to send it via a <code>java.io.InputStream</code> object.
     * The data will be read from the stream as needed until end-of-file is reached.
     * <P>
     * <B>Note:</B> This stream object can either be a standard Java stream object or your own subclass that implements the
     * standard interface.
     * <P>
     * <B>Note:</B> Consult your JDBC driver documentation to determine if it might be more efficient to use a version of
     * <code>setBinaryStream</code> which takes a length parameter.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param x the java input stream which contains the binary parameter value
     * @exception SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if a database
     * access error occurs or this method is called on a closed <code>PreparedStatement</code>
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setBinaryStream(int parameterIndex, java.io.InputStream x) throws SQLException {
        checkIfValid();
        pstmt.setBinaryStream(parameterIndex, x);
    }

    /**
     * Sets the designated parameter to the given <code>Reader</code> object. When a very large UNICODE value is input to a
     * <code>LONGVARCHAR</code> parameter, it may be more practical to send it via a <code>java.io.Reader</code> object. The data
     * will be read from the stream as needed until end-of-file is reached. The JDBC driver will do any necessary conversion from
     * UNICODE to the database char format.
     * <P>
     * <B>Note:</B> This stream object can either be a standard Java stream object or your own subclass that implements the
     * standard interface.
     * <P>
     * <B>Note:</B> Consult your JDBC driver documentation to determine if it might be more efficient to use a version of
     * <code>setCharacterStream</code> which takes a length parameter.
     * @param parameterIndex the first parameter is 1, the second is 2, ...
     * @param reader the <code>java.io.Reader</code> object that contains the Unicode data
     * @exception SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if a database
     * access error occurs or this method is called on a closed <code>PreparedStatement</code>
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setCharacterStream(int parameterIndex, java.io.Reader reader) throws SQLException {
        checkIfValid();
        pstmt.setCharacterStream(parameterIndex, reader);
    }

    /**
     * Sets the designated parameter to a <code>Reader</code> object. The <code>Reader</code> reads the data till end-of-file is
     * reached. The driver does the necessary conversion from Java character format to the national character set in the database.
     * <P>
     * <B>Note:</B> This stream object can either be a standard Java stream object or your own subclass that implements the
     * standard interface.
     * <P>
     * <B>Note:</B> Consult your JDBC driver documentation to determine if it might be more efficient to use a version of
     * <code>setNCharacterStream</code> which takes a length parameter.
     * @param parameterIndex of the first parameter is 1, the second is 2, ...
     * @param value the parameter value
     * @throws SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if the driver does
     * not support national character sets; if the driver can detect that a data conversion error could occur; if a database
     * access error occurs; or this method is called on a closed <code>PreparedStatement</code>
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setNCharacterStream(int parameterIndex, Reader value) throws SQLException {
        checkIfValid();
        pstmt.setNCharacterStream(parameterIndex, value);
    }

    /**
     * Sets the designated parameter to a <code>Reader</code> object. This method differs from the
     * <code>setCharacterStream (int, Reader)</code> method because it informs the driver that the parameter value should be sent
     * to the server as a <code>CLOB</code>. When the <code>setCharacterStream</code> method is used, the driver may have to do
     * extra work to determine whether the parameter data should be sent to the server as a <code>LONGVARCHAR</code> or a
     * <code>CLOB</code>
     * <P>
     * <B>Note:</B> Consult your JDBC driver documentation to determine if it might be more efficient to use a version of
     * <code>setClob</code> which takes a length parameter.
     * @param parameterIndex index of the first parameter is 1, the second is 2, ...
     * @param reader An object that contains the data to set the parameter value to.
     * @throws SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if a database access
     * error occurs; this method is called on a closed <code>PreparedStatement</code>or if parameterIndex does not correspond to a
     * parameter marker in the SQL statement
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setClob(int parameterIndex, Reader reader) throws SQLException {
        checkIfValid();
        pstmt.setClob(parameterIndex, reader);
    }

    /**
     * Sets the designated parameter to a <code>InputStream</code> object. This method differs from the
     * <code>setBinaryStream (int, InputStream)</code> method because it informs the driver that the parameter value should be
     * sent to the server as a <code>BLOB</code>. When the <code>setBinaryStream</code> method is used, the driver may have to do
     * extra work to determine whether the parameter data should be sent to the server as a <code>LONGVARBINARY</code> or a
     * <code>BLOB</code>
     * <P>
     * <B>Note:</B> Consult your JDBC driver documentation to determine if it might be more efficient to use a version of
     * <code>setBlob</code> which takes a length parameter.
     * @param parameterIndex index of the first parameter is 1, the second is 2, ...
     * @param inputStream An object that contains the data to set the parameter value to.
     * @throws SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if a database access
     * error occurs; this method is called on a closed <code>PreparedStatement</code> or if parameterIndex does not correspond to
     * a parameter marker in the SQL statement,
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setBlob(int parameterIndex, InputStream inputStream) throws SQLException {
        checkIfValid();
        pstmt.setBlob(parameterIndex, inputStream);
    }

    /**
     * Sets the designated parameter to a <code>Reader</code> object. This method differs from the
     * <code>setCharacterStream (int, Reader)</code> method because it informs the driver that the parameter value should be sent
     * to the server as a <code>NCLOB</code>. When the <code>setCharacterStream</code> method is used, the driver may have to do
     * extra work to determine whether the parameter data should be sent to the server as a <code>LONGNVARCHAR</code> or a
     * <code>NCLOB</code>
     * <P>
     * <B>Note:</B> Consult your JDBC driver documentation to determine if it might be more efficient to use a version of
     * <code>setNClob</code> which takes a length parameter.
     * @param parameterIndex index of the first parameter is 1, the second is 2, ...
     * @param reader An object that contains the data to set the parameter value to.
     * @throws SQLException if parameterIndex does not correspond to a parameter marker in the SQL statement; if the driver does
     * not support national character sets; if the driver can detect that a data conversion error could occur; if a database
     * access error occurs or this method is called on a closed <code>PreparedStatement</code>
     * @throws SQLFeatureNotSupportedException if the JDBC driver does not support this method
     * @since 1.6
     */
    public void setNClob(int parameterIndex, Reader reader) throws SQLException {
        checkIfValid();
        pstmt.setNClob(parameterIndex, reader);
    }



    /**
     * Requests that a <code>Statement</code> be pooled or not pooled. The value specified is a hint to the statement pool
     * implementation indicating whether the applicaiton wants the statement to be pooled. It is up to the statement pool manager
     * as to whether the hint is used.
     * <p>
     * The poolable value of a statement is applicable to both internal statement caches implemented by the driver and external
     * statement caches implemented by application servers and other applications.
     * <p>
     * By default, a <code>Statement</code> is not poolable when created, and a <code>PreparedStatement</code> and
     * <code>CallableStatement</code> are poolable when created.
     * <p>
     * @param poolable requests that the statement be pooled if true and that the statement not be pooled if false
     * <p>
     * @throws SQLException if this method is called on a closed <code>Statement</code>
     * <p>
     * @since 1.6
     */
    public void setPoolable(boolean poolable) throws SQLException {
        checkIfValid();
        pstmt.setPoolable(poolable);
    }

    /**
     * Returns a value indicating whether the <code>Statement</code> is poolable or not.
     * <p>
     * @return <code>true</code> if the <code>Statement</code> is poolable; <code>false</code> otherwise
     * <p>
     * @throws SQLException if this method is called on a closed <code>Statement</code>
     * <p>
     * @since 1.6
     * <p>
     * @see java.sql.Statement#setPoolable(boolean) setPoolable(boolean)
     */
    public boolean isPoolable() throws SQLException {
        checkIfValid();
        return pstmt.isPoolable();
    }

    /**
     * Returns true if this either implements the interface argument or is directly or indirectly a wrapper for an object that does.
     * Returns false otherwise. If this implements the interface then return true, else if this is a wrapper then return the result
     * of recursively calling isWrapperFor on the wrapped object. If this does not implement the interface and is not a wrapper,
     * return false. This method should be implemented as a low-cost operation compared to unwrap so that callers can use this method
     * to avoid expensive unwrap calls that may fail. If this method returns true then calling unwrap with the same argument should succeed.
     * @param iface a Class defining an interface. 
     * @returns true if this implements the interface or directly or indirectly wraps an object that does. 
     * @throws SQLException if an error occurs while determining whether this is a wrapper for an object with the given interface.
     */
    public boolean isWrapperFor(Class<?> iface) throws SQLException {
        checkIfValid();
        return pstmt.isWrapperFor(iface);
    }

    /**
     * Returns an object that implements the given interface to allow access to non-standard methods, or standard methods not exposed by the proxy.
     * If the receiver implements the interface then the result is the receiver or a proxy for the receiver. If the receiver is a wrapper
     * and the wrapped object implements the interface then the result is the wrapped object or a proxy for the wrapped object.
     * Otherwise return the the result of calling unwrap recursively on the wrapped object or a proxy for that result. 
     * If the receiver is not a wrapper and does not implement the interface, then an SQLException is thrown.
     * @param iface A Class defining an interface that the result must implement. 
     * @returns an object that implements the interface. May be a proxy for the actual implementing object. 
     * @throws SQLException If no object found that implements the interface
     */
    public <T> T unwrap(Class<T> iface) throws SQLException {
        checkIfValid();
        return pstmt.unwrap(iface);
    }

}
