/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.ignite.internal.jdbc2;

import java.io.InputStream;
import java.io.Reader;
import java.math.BigDecimal;
import java.net.MalformedURLException;
import java.net.URL;
import java.sql.Array;
import java.sql.Blob;
import java.sql.Clob;
import java.sql.Date;
import java.sql.NClob;
import java.sql.Ref;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.RowId;
import java.sql.SQLException;
import java.sql.SQLFeatureNotSupportedException;
import java.sql.SQLWarning;
import java.sql.SQLXML;
import java.sql.Statement;
import java.sql.Time;
import java.sql.Timestamp;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.UUID;
import org.apache.ignite.Ignite;
import org.apache.ignite.internal.processors.odbc.SqlStateCode;
import org.apache.ignite.internal.util.typedef.F;
import org.jetbrains.annotations.Nullable;

import static org.apache.ignite.internal.jdbc2.JdbcUtils.convertToSqlException;

/**
 * JDBC result set implementation.
 */
public class JdbcResultSet implements ResultSet {
    /** Decimal format to convert streing to decimal. */
    private static final ThreadLocal<DecimalFormat> decimalFormat = new ThreadLocal<DecimalFormat>() {
        /** {@inheritDoc} */
        @Override protected DecimalFormat initialValue() {
            DecimalFormatSymbols symbols = new DecimalFormatSymbols();

            symbols.setGroupingSeparator(',');
            symbols.setDecimalSeparator('.');

            String ptrn = "#,##0.0#";

            DecimalFormat decimalFormat = new DecimalFormat(ptrn, symbols);

            decimalFormat.setParseBigDecimal(true);

            return decimalFormat;
        }
    };

    /** Is query. */
    private final boolean isQry;

    /** Update count. */
    private final long updCnt;

    /** Uuid. */
    private final UUID uuid;

    /** Statement. */
    private final JdbcStatement stmt;

    /** Table names. */
    private List<String> tbls;

    /** Column names. */
    private List<String> cols;

    /** Class names. */
    private List<String> types;

    /** Rows cursor iterator. */
    private Iterator<List<?>> it;

    /** Finished flag. */
    private boolean finished;

    /** Current position. */
    private int pos;

    /** Current. */
    private List<Object> curr;

    /** Closed flag. */
    private boolean closed;

    /** Was {@code NULL} flag. */
    private boolean wasNull;

    /** Fetch size. */
    private int fetchSize;

    /**
     * Creates new result set.
     *
     * @param isQry Is query flag.
     * @param uuid Query UUID.
     * @param stmt Statement.
     * @param tbls Table names.
     * @param cols Column names.
     * @param types Types.
     * @param fields Fields.
     * @param finished Result set finished flag (the last result set).
     * @throws SQLException On error.
     */
    JdbcResultSet(boolean isQry, @Nullable UUID uuid, JdbcStatement stmt, List<String> tbls, List<String> cols,
        List<String> types, List<List<?>> fields, boolean finished) throws SQLException {
        this.isQry = isQry;
        this.stmt = stmt;

        if (isQry) {
            this.uuid = uuid;
            updCnt = -1;
            this.tbls = tbls;
            this.cols = cols;
            this.types = types;
            this.finished = finished;

            if (fields != null)
                it = fields.iterator();
            else
                it = Collections.emptyIterator();
        }
        else {
            updCnt = updateCounterFromQueryResult(fields);

            this.uuid = null;
            this.tbls = null;
            this.cols = null;
            this.types = null;
            this.finished = true;
            it = null;
        }
    }

    /**
     * @param stmt Statement.
     * @param updCnt Update count.
     */
    JdbcResultSet(JdbcStatement stmt, long updCnt) {
        isQry = false;
        this.updCnt = updCnt;
        this.stmt = stmt;

        uuid = null;
        tbls = null;
        cols = null;
        types = null;
        finished = true;
        it = null;
    }

        /** {@inheritDoc} */
    @SuppressWarnings("unchecked")
    @Override public boolean next() throws SQLException {
        ensureNotClosed();

        if (it == null || (stmt.getMaxRows() > 0 && pos >= stmt.getMaxRows())) {
            curr = null;

            return false;
        }
        else if (it.hasNext()) {
            curr = new ArrayList<>(it.next());

            pos++;

            if (finished && !it.hasNext())
                it = null;

            return true;
        }
        else if (!finished) {
            fetchPage();

            return next();
        }

        it = null;

        return false;
    }

    /**
     * Fetch next results page.
     *
     * @throws SQLException On error.
     */
    private void fetchPage() throws SQLException {
        JdbcConnection conn = (JdbcConnection)stmt.getConnection();

        Ignite ignite = conn.ignite();

        UUID nodeId = conn.nodeId();

        boolean loc = nodeId == null;

        boolean updateMetadata = tbls == null;

        // Connections from new clients send queries with new tasks, so we have to continue in the same manner
        JdbcQueryTask qryTask = JdbcQueryTaskV3.createTask(loc ? ignite : null, conn.cacheName(), conn.schemaName(),
            null,true, loc, null, fetchSize, uuid, conn.isLocalQuery(), conn.isCollocatedQuery(),
            conn.isDistributedJoins(), conn.isEnforceJoinOrder(), conn.isLazy(), updateMetadata, false);

        try {
            JdbcQueryTaskResult res =
                loc ? qryTask.call() : ignite.compute(ignite.cluster().forNodeId(nodeId)).call(qryTask);

            finished = res.isFinished();

            it = res.getRows().iterator();

            if (updateMetadata) {
                tbls = res.getTbls();
                cols = res.getCols();
                types = res.getTypes();
            }
        }
        catch (Exception e) {
            throw convertToSqlException(e, "Failed to query Ignite.");
        }
    }

    /** {@inheritDoc} */
    @Override public void close() throws SQLException {
        if (uuid != null)
            stmt.resSets.remove(this);

        closeInternal();
    }

    /**
     * Marks result set as closed.
     * If this result set is associated with locally executed query then query cursor will also closed.
     * @throws SQLException On error.
     */
    void closeInternal() throws SQLException  {
        if (((JdbcConnection)stmt.getConnection()).nodeId() == null && uuid != null)
            JdbcQueryTask.remove(uuid);

        closed = true;
    }

    /** {@inheritDoc} */
    @Override public boolean wasNull() throws SQLException {
        return wasNull;
    }

    /** {@inheritDoc} */
    @Override public String getString(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        return val == null ? null : String.valueOf(val);
    }

    /** {@inheritDoc} */
    @Override public boolean getBoolean(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return false;

        Class<?> cls = val.getClass();

        if (cls == Boolean.class)
            return ((Boolean)val);
        else if (val instanceof Number)
            return ((Number)val).intValue() != 0;
        else if (cls == String.class || cls == Character.class) {
            try {
                return Integer.parseInt(val.toString()) != 0;
            }
            catch (NumberFormatException e) {
                throw new SQLException("Cannot convert to boolean: " + val, SqlStateCode.CONVERSION_FAILED, e);
            }
        }
        else
            throw new SQLException("Cannot convert to boolean: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public byte getByte(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return 0;

        Class<?> cls = val.getClass();

        if (val instanceof Number)
            return ((Number)val).byteValue();
        else if (cls == Boolean.class)
            return (Boolean) val ? (byte) 1 : (byte) 0;
        else if (cls == String.class || cls == Character.class) {
            try {
                return Byte.parseByte(val.toString());
            }
            catch (NumberFormatException e) {
                throw new SQLException("Cannot convert to byte: " + val, SqlStateCode.CONVERSION_FAILED, e);
            }
        }
        else
            throw new SQLException("Cannot convert to byte: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public short getShort(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return 0;

        Class<?> cls = val.getClass();

        if (val instanceof Number)
            return ((Number) val).shortValue();
        else if (cls == Boolean.class)
            return (Boolean) val ? (short) 1 : (short) 0;
        else if (cls == String.class || cls == Character.class) {
            try {
                return Short.parseShort(val.toString());
            }
            catch (NumberFormatException e) {
                throw new SQLException("Cannot convert to short: " + val, SqlStateCode.CONVERSION_FAILED, e);
            }
        }
        else
            throw new SQLException("Cannot convert to short: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public int getInt(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return 0;

        Class<?> cls = val.getClass();

        if (val instanceof Number)
            return ((Number) val).intValue();
        else if (cls == Boolean.class)
            return (Boolean) val ? 1 : 0;
        else if (cls == String.class || cls == Character.class) {
            try {
                return Integer.parseInt(val.toString());
            }
            catch (NumberFormatException e) {
                throw new SQLException("Cannot convert to int: " + val, SqlStateCode.CONVERSION_FAILED, e);
            }
        }
        else
            throw new SQLException("Cannot convert to int: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public long getLong(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return 0;

        Class<?> cls = val.getClass();

        if (val instanceof Number)
            return ((Number)val).longValue();
        else if (cls == Boolean.class)
            return (long) ((Boolean) val ? 1 : 0);
        else if (cls == String.class || cls == Character.class) {
            try {
                return Long.parseLong(val.toString());
            }
            catch (NumberFormatException e) {
                throw new SQLException("Cannot convert to long: " + val, SqlStateCode.CONVERSION_FAILED, e);
            }
        }
        else
            throw new SQLException("Cannot convert to long: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public float getFloat(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return 0;

        Class<?> cls = val.getClass();

        if (val instanceof Number)
            return ((Number) val).floatValue();
        else if (cls == Boolean.class)
            return (float) ((Boolean) val ? 1 : 0);
        else if (cls == String.class || cls == Character.class) {
            try {
                return Float.parseFloat(val.toString());
            }
            catch (NumberFormatException e) {
                throw new SQLException("Cannot convert to float: " + val, SqlStateCode.CONVERSION_FAILED, e);
            }
        }
        else
            throw new SQLException("Cannot convert to float: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public double getDouble(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return 0;

        Class<?> cls = val.getClass();

        if (val instanceof Number)
            return ((Number) val).doubleValue();
        else if (cls == Boolean.class)
            return (double)((Boolean) val ? 1 : 0);
        else if (cls == String.class || cls == Character.class) {
            try {
                return Double.parseDouble(val.toString());
            }
            catch (NumberFormatException e) {
                throw new SQLException("Cannot convert to double: " + val, SqlStateCode.CONVERSION_FAILED, e);
            }
        }
        else
            throw new SQLException("Cannot convert to double: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public BigDecimal getBigDecimal(int colIdx, int scale) throws SQLException {
        BigDecimal val = getBigDecimal(colIdx);

        return val == null ? null : val.setScale(scale, BigDecimal.ROUND_HALF_UP);
    }

    /** {@inheritDoc} */
    @Override public byte[] getBytes(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return null;

        Class<?> cls = val.getClass();

        if (cls == byte[].class)
            return (byte[])val;
        else if (cls == Byte.class)
            return new byte[] {(byte)val};
        else if (cls == Short.class) {
            short x = (short)val;

            return new byte[] {(byte)(x >> 8), (byte)x};
        }
        else if (cls == Integer.class) {
            int x = (int)val;

            return new byte[] { (byte) (x >> 24), (byte) (x >> 16), (byte) (x >> 8), (byte) x};
        }
        else if (cls == Long.class) {
            long x = (long)val;

            return new byte[] {(byte) (x >> 56), (byte) (x >> 48), (byte) (x >> 40), (byte) (x >> 32),
                (byte) (x >> 24), (byte) (x >> 16), (byte) (x >> 8), (byte) x};
        }
        else if (cls == String.class)
            return ((String)val).getBytes();
        else
            throw new SQLException("Cannot convert to byte[]: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public Date getDate(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return null;

        Class<?> cls = val.getClass();

        if (cls == Date.class)
            return (Date)val;
        else if (cls == java.util.Date.class || cls == Time.class || cls == Timestamp.class)
            return new Date(((java.util.Date)val).getTime());
        else
            throw new SQLException("Cannot convert to date: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public Time getTime(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return null;

        Class<?> cls = val.getClass();

        if (cls == Time.class)
            return (Time)val;
        else if (cls == java.util.Date.class || cls == Date.class || cls == Timestamp.class)
            return new Time(((java.util.Date)val).getTime());
        else
            throw new SQLException("Cannot convert to time: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public Timestamp getTimestamp(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return null;

        Class<?> cls = val.getClass();

        if (cls == Timestamp.class)
            return (Timestamp)val;
        else if (cls == java.util.Date.class || cls == Date.class || cls == Time.class)
            return new Timestamp(((java.util.Date)val).getTime());
        else
            throw new SQLException("Cannot convert to timestamp: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public InputStream getAsciiStream(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Streams are not supported.");
    }

    /** {@inheritDoc} */
    @Override public InputStream getUnicodeStream(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Streams are not supported.");
    }

    /** {@inheritDoc} */
    @Override public InputStream getBinaryStream(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Stream are not supported.");
    }

    /** {@inheritDoc} */
    @Override public String getString(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getString(colIdx);
    }

    /** {@inheritDoc} */
    @Override public boolean getBoolean(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getBoolean(colIdx);
    }

    /** {@inheritDoc} */
    @Override public byte getByte(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getByte(colIdx);
    }

    /** {@inheritDoc} */
    @Override public short getShort(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getShort(colIdx);
    }

    /** {@inheritDoc} */
    @Override public int getInt(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getInt(colIdx);
    }

    /** {@inheritDoc} */
    @Override public long getLong(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getLong(colIdx);
    }

    /** {@inheritDoc} */
    @Override public float getFloat(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getFloat(colIdx);
    }

    /** {@inheritDoc} */
    @Override public double getDouble(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getDouble(colIdx);
    }

    /** {@inheritDoc} */
    @Override public BigDecimal getBigDecimal(String colLb, int scale) throws SQLException {
        int colIdx = findColumn(colLb);

        return getBigDecimal(colIdx, scale);
    }

    /** {@inheritDoc} */
    @Override public byte[] getBytes(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getBytes(colIdx);
    }

    /** {@inheritDoc} */
    @Override public Date getDate(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getDate(colIdx);
    }

    /** {@inheritDoc} */
    @Override public Time getTime(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getTime(colIdx);
    }

    /** {@inheritDoc} */
    @Override public Timestamp getTimestamp(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getTimestamp(colIdx);
    }

    /** {@inheritDoc} */
    @Override public InputStream getAsciiStream(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Streams are not supported.");
    }

    /** {@inheritDoc} */
    @Override public InputStream getUnicodeStream(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Streams are not supported.");
    }

    /** {@inheritDoc} */
    @Override public InputStream getBinaryStream(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Streams are not supported.");
    }

    /** {@inheritDoc} */
    @Override public SQLWarning getWarnings() throws SQLException {
        ensureNotClosed();

        return null;
    }

    /** {@inheritDoc} */
    @Override public void clearWarnings() throws SQLException {
        ensureNotClosed();
    }

    /** {@inheritDoc} */
    @Override public String getCursorName() throws SQLException {
        ensureNotClosed();

        return null;
    }

    /** {@inheritDoc} */
    @Override public ResultSetMetaData getMetaData() throws SQLException {
        ensureNotClosed();

        if (tbls == null)
            fetchPage();

        return new JdbcResultSetMetadata(tbls, cols, types);
    }

    /** {@inheritDoc} */
    @Override public Object getObject(int colIdx) throws SQLException {
        return getValue(colIdx);
    }

    /** {@inheritDoc} */
    @Override public Object getObject(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getValue(colIdx);
    }

    /** {@inheritDoc} */
    @Override public int findColumn(String colLb) throws SQLException {
        ensureNotClosed();

        int idx = cols.indexOf(colLb.toUpperCase());

        if (idx == -1)
            throw new SQLException("Column not found: " + colLb);

        assert idx >= 0;

        return idx + 1;
    }

    /** {@inheritDoc} */
    @Override public Reader getCharacterStream(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Streams are not supported.");
    }

    /** {@inheritDoc} */
    @Override public Reader getCharacterStream(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Streams are not supported.");
    }

    /** {@inheritDoc} */
    @Override public BigDecimal getBigDecimal(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return null;

        Class<?> cls = val.getClass();

        if (cls == BigDecimal.class)
            return (BigDecimal)val;
        else if (val instanceof Number)
            return new BigDecimal(((Number)val).doubleValue());
        else if (cls == Boolean.class)
            return new BigDecimal((Boolean)val ? 1 : 0);
        else if (cls == String.class || cls == Character.class) {
            try {
                return (BigDecimal)decimalFormat.get().parse(val.toString());
            }
            catch (ParseException e) {
                throw new SQLException("Cannot convert to BigDecimal: " + val, SqlStateCode.CONVERSION_FAILED, e);
            }
        }
        else
            throw new SQLException("Cannot convert to BigDecimal: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public BigDecimal getBigDecimal(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getBigDecimal(colIdx);
    }

    /** {@inheritDoc} */
    @Override public boolean isBeforeFirst() throws SQLException {
        ensureNotClosed();

        return pos < 1;
    }

    /** {@inheritDoc} */
    @Override public boolean isAfterLast() throws SQLException {
        ensureNotClosed();

        return finished && it == null && curr == null;
    }

    /** {@inheritDoc} */
    @Override public boolean isFirst() throws SQLException {
        ensureNotClosed();

        return pos == 1;
    }

    /** {@inheritDoc} */
    @Override public boolean isLast() throws SQLException {
        ensureNotClosed();

        return finished && it == null && curr != null;
    }

    /** {@inheritDoc} */
    @Override public void beforeFirst() throws SQLException {
        ensureNotClosed();

        throw new SQLException("Result set is forward-only.");
    }

    /** {@inheritDoc} */
    @Override public void afterLast() throws SQLException {
        ensureNotClosed();

        throw new SQLException("Result set is forward-only.");
    }

    /** {@inheritDoc} */
    @Override public boolean first() throws SQLException {
        ensureNotClosed();

        throw new SQLException("Result set is forward-only.");
    }

    /** {@inheritDoc} */
    @Override public boolean last() throws SQLException {
        ensureNotClosed();

        throw new SQLException("Result set is forward-only.");
    }

    /** {@inheritDoc} */
    @Override public int getRow() throws SQLException {
        ensureNotClosed();

        return isAfterLast() ? 0 : pos;
    }

    /** {@inheritDoc} */
    @Override public boolean absolute(int row) throws SQLException {
        ensureNotClosed();

        throw new SQLException("Result set is forward-only.");
    }

    /** {@inheritDoc} */
    @Override public boolean relative(int rows) throws SQLException {
        ensureNotClosed();

        throw new SQLException("Result set is forward-only.");
    }

    /** {@inheritDoc} */
    @Override public boolean previous() throws SQLException {
        ensureNotClosed();

        throw new SQLException("Result set is forward-only.");
    }

    /** {@inheritDoc} */
    @Override public void setFetchDirection(int direction) throws SQLException {
        ensureNotClosed();

        if (direction != FETCH_FORWARD)
            throw new SQLFeatureNotSupportedException("Only forward direction is supported");
    }

    /** {@inheritDoc} */
    @Override public int getFetchDirection() throws SQLException {
        ensureNotClosed();

        return FETCH_FORWARD;
    }

    /** {@inheritDoc} */
    @Override public void setFetchSize(int fetchSize) throws SQLException {
        ensureNotClosed();

        if (fetchSize <= 0)
            throw new SQLException("Fetch size must be greater than zero.");

        this.fetchSize = fetchSize;
    }

    /** {@inheritDoc} */
    @Override public int getFetchSize() throws SQLException {
        ensureNotClosed();

        return fetchSize;
    }

    /** {@inheritDoc} */
    @Override public int getType() throws SQLException {
        ensureNotClosed();

        return stmt.getResultSetType();
    }

    /** {@inheritDoc} */
    @Override public int getConcurrency() throws SQLException {
        ensureNotClosed();

        return CONCUR_READ_ONLY;
    }

    /** {@inheritDoc} */
    @Override public boolean rowUpdated() throws SQLException {
        ensureNotClosed();

        return false;
    }

    /** {@inheritDoc} */
    @Override public boolean rowInserted() throws SQLException {
        ensureNotClosed();

        return false;
    }

    /** {@inheritDoc} */
    @Override public boolean rowDeleted() throws SQLException {
        ensureNotClosed();

        return false;
    }

    /** {@inheritDoc} */
    @Override public void updateNull(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBoolean(int colIdx, boolean x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateByte(int colIdx, byte x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateShort(int colIdx, short x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateInt(int colIdx, int x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateLong(int colIdx, long x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateFloat(int colIdx, float x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateDouble(int colIdx, double x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBigDecimal(int colIdx, BigDecimal x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateString(int colIdx, String x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBytes(int colIdx, byte[] x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateDate(int colIdx, Date x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateTime(int colIdx, Time x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateTimestamp(int colIdx, Timestamp x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateAsciiStream(int colIdx, InputStream x, int len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBinaryStream(int colIdx, InputStream x, int len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateCharacterStream(int colIdx, Reader x, int len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateObject(int colIdx, Object x, int scaleOrLen) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateObject(int colIdx, Object x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateNull(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBoolean(String colLb, boolean x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateByte(String colLb, byte x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateShort(String colLb, short x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateInt(String colLb, int x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateLong(String colLb, long x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateFloat(String colLb, float x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateDouble(String colLb, double x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBigDecimal(String colLb, BigDecimal x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateString(String colLb, String x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBytes(String colLb, byte[] x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateDate(String colLb, Date x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateTime(String colLb, Time x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateTimestamp(String colLb, Timestamp x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateAsciiStream(String colLb, InputStream x, int len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBinaryStream(String colLb, InputStream x, int len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateCharacterStream(String colLb, Reader reader, int len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateObject(String colLb, Object x, int scaleOrLen) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateObject(String colLb, Object x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void insertRow() throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateRow() throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void deleteRow() throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void refreshRow() throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Row refreshing is not supported.");
    }

    /** {@inheritDoc} */
    @Override public void cancelRowUpdates() throws SQLException {
        ensureNotClosed();
    }

    /** {@inheritDoc} */
    @Override public void moveToInsertRow() throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void moveToCurrentRow() throws SQLException {
        ensureNotClosed();
    }

    /** {@inheritDoc} */
    @Override public Statement getStatement() throws SQLException {
        ensureNotClosed();

        return stmt;
    }

    /** {@inheritDoc} */
    @Override public Object getObject(int colIdx, Map<String, Class<?>> map) throws SQLException {
        throw new SQLFeatureNotSupportedException("SQL structured type are not supported.");
    }

    /** {@inheritDoc} */
    @Override public Ref getRef(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public Blob getBlob(int colIdx) throws SQLException {
        return new JdbcBlob(getBytes(colIdx));
    }

    /** {@inheritDoc} */
    @Override public Clob getClob(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public Array getArray(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public Object getObject(String colLb, Map<String, Class<?>> map) throws SQLException {
        throw new SQLFeatureNotSupportedException("SQL structured type are not supported.");
    }

    /** {@inheritDoc} */
    @Override public Ref getRef(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public Blob getBlob(String colLb) throws SQLException {
        return new JdbcBlob(getBytes(colLb));
    }

    /** {@inheritDoc} */
    @Override public Clob getClob(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public Array getArray(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public Date getDate(int colIdx, Calendar cal) throws SQLException {
        return getDate(colIdx);
    }

    /** {@inheritDoc} */
    @Override public Date getDate(String colLb, Calendar cal) throws SQLException {
        return getDate(colLb);
    }

    /** {@inheritDoc} */
    @Override public Time getTime(int colIdx, Calendar cal) throws SQLException {
        return getTime(colIdx);
    }

    /** {@inheritDoc} */
    @Override public Time getTime(String colLb, Calendar cal) throws SQLException {
        return getTime(colLb);
    }

    /** {@inheritDoc} */
    @Override public Timestamp getTimestamp(int colIdx, Calendar cal) throws SQLException {
        return getTimestamp(colIdx);
    }

    /** {@inheritDoc} */
    @Override public Timestamp getTimestamp(String colLb, Calendar cal) throws SQLException {
        return getTimestamp(colLb);
    }

    /** {@inheritDoc} */
    @Override public URL getURL(int colIdx) throws SQLException {
        Object val = getValue(colIdx);

        if (val == null)
            return null;

        Class<?> cls = val.getClass();

        if (cls == URL.class)
            return (URL)val;
        else if (cls == String.class) {
            try {
                return new URL(val.toString());
            }
            catch (MalformedURLException e) {
                throw new SQLException("Cannot convert to URL: " + val, SqlStateCode.CONVERSION_FAILED, e);
            }
        }
        else
            throw new SQLException("Cannot convert to URL: " + val, SqlStateCode.CONVERSION_FAILED);
    }

    /** {@inheritDoc} */
    @Override public URL getURL(String colLb) throws SQLException {
        int colIdx = findColumn(colLb);

        return getURL(colIdx);
    }

    /** {@inheritDoc} */
    @Override public void updateRef(int colIdx, Ref x) throws SQLException {
        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateRef(String colLb, Ref x) throws SQLException {
        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBlob(int colIdx, Blob x) throws SQLException {
        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBlob(String colLb, Blob x) throws SQLException {
        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateClob(int colIdx, Clob x) throws SQLException {
        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateClob(String colLb, Clob x) throws SQLException {
        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateArray(int colIdx, Array x) throws SQLException {
        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateArray(String colLb, Array x) throws SQLException {
        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public RowId getRowId(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public RowId getRowId(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateRowId(int colIdx, RowId x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateRowId(String colLb, RowId x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public int getHoldability() throws SQLException {
        ensureNotClosed();

        return HOLD_CURSORS_OVER_COMMIT;
    }

    /** {@inheritDoc} */
    @Override public boolean isClosed() throws SQLException {
        return closed;
    }

    /** {@inheritDoc} */
    @Override public void updateNString(int colIdx, String nStr) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateNString(String colLb, String nStr) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateNClob(int colIdx, NClob nClob) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateNClob(String colLb, NClob nClob) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public NClob getNClob(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public NClob getNClob(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public SQLXML getSQLXML(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public SQLXML getSQLXML(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateSQLXML(int colIdx, SQLXML xmlObj) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateSQLXML(String colLb, SQLXML xmlObj) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public String getNString(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public String getNString(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public Reader getNCharacterStream(int colIdx) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public Reader getNCharacterStream(String colLb) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("SQL-specific types are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateNCharacterStream(int colIdx, Reader x, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateNCharacterStream(String colLb, Reader reader, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateAsciiStream(int colIdx, InputStream x, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBinaryStream(int colIdx, InputStream x, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateCharacterStream(int colIdx, Reader x, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateAsciiStream(String colLb, InputStream x, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBinaryStream(String colLb, InputStream x, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateCharacterStream(String colLb, Reader reader, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBlob(int colIdx, InputStream inputStream, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBlob(String colLb, InputStream inputStream, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateClob(int colIdx, Reader reader, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateClob(String colLb, Reader reader, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateNClob(int colIdx, Reader reader, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateNClob(String colLb, Reader reader, long len) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateNCharacterStream(int colIdx, Reader x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateNCharacterStream(String colLb, Reader reader) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateAsciiStream(int colIdx, InputStream x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBinaryStream(int colIdx, InputStream x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateCharacterStream(int colIdx, Reader x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateAsciiStream(String colLb, InputStream x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBinaryStream(String colLb, InputStream x) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateCharacterStream(String colLb, Reader reader) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBlob(int colIdx, InputStream inputStream) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateBlob(String colLb, InputStream inputStream) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateClob(int colIdx, Reader reader) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateClob(String colLb, Reader reader) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateNClob(int colIdx, Reader reader) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @Override public void updateNClob(String colLb, Reader reader) throws SQLException {
        ensureNotClosed();

        throw new SQLFeatureNotSupportedException("Updates are not supported.");
    }

    /** {@inheritDoc} */
    @SuppressWarnings("unchecked")
    @Override public <T> T unwrap(Class<T> iface) throws SQLException {
        if (!isWrapperFor(iface))
            throw new SQLException("Result set is not a wrapper for " + iface.getName());

        return (T)this;
    }

    /** {@inheritDoc} */
    @Override public boolean isWrapperFor(Class<?> iface) throws SQLException {
        return iface != null && iface == ResultSet.class;
    }

    /** {@inheritDoc} */
    @Override public <T> T getObject(int colIdx, Class<T> targetCls) throws SQLException {
        return (T)getObject0(colIdx, targetCls);
    }

    /** {@inheritDoc} */
    @Override public <T> T getObject(String colLb, Class<T> targetCls) throws SQLException {
        int colIdx = findColumn(colLb);

        return getObject(colIdx, targetCls);
    }

    /**
     * @param colIdx Column index.
     * @param targetCls Class representing the Java data type to convert the designated column to.
     * @return Converted object.
     * @throws SQLException On error.
     */
    private Object getObject0(int colIdx, Class<?> targetCls) throws SQLException {
        if (targetCls == Boolean.class)
            return getBoolean(colIdx);
        else if (targetCls == Byte.class)
            return getByte(colIdx);
        else if (targetCls == Short.class)
            return getShort(colIdx);
        else if (targetCls == Integer.class)
            return getInt(colIdx);
        else if (targetCls == Long.class)
            return getLong(colIdx);
        else if (targetCls == Float.class)
            return getFloat(colIdx);
        else if (targetCls == Double.class)
            return getDouble(colIdx);
        else if (targetCls == String.class)
            return getString(colIdx);
        else if (targetCls == BigDecimal.class)
            return getBigDecimal(colIdx);
        else if (targetCls == Date.class)
            return getDate(colIdx);
        else if (targetCls == Time.class)
            return getTime(colIdx);
        else if (targetCls == Timestamp.class)
            return getTimestamp(colIdx);
        else if (targetCls == byte[].class)
            return getBytes(colIdx);
        else if (targetCls == URL.class)
            return getURL(colIdx);
        else {
            Object val = getValue(colIdx);

            if (val == null)
                return null;

            Class<?> cls = val.getClass();

            if (targetCls == cls)
                return val;
            else
                throw new SQLException("Cannot convert to " + targetCls.getName() + ": " + val,
                    SqlStateCode.CONVERSION_FAILED);
        }
    }

    /**
     * Gets object field value by index.
     *
     * @param colIdx Column index.
     * @return Object field value.
     * @throws SQLException In case of error.
     */
    @SuppressWarnings("unchecked")
    private Object getValue(int colIdx) throws SQLException {
        ensureNotClosed();
        ensureHasCurrentRow();

        try {
            Object val = curr.get(colIdx - 1);

            wasNull = val == null;

            return val;
        }
        catch (IndexOutOfBoundsException e) {
            throw new SQLException("Invalid column index: " + colIdx, e);
        }
    }

    /**
     * Ensures that result set is not closed.
     *
     * @throws SQLException If result set is closed.
     */
    private void ensureNotClosed() throws SQLException {
        if (closed)
            throw new SQLException("Result set is closed.", SqlStateCode.INVALID_CURSOR_STATE);
    }

    /**
     * Ensures that result set is positioned on a row.
     *
     * @throws SQLException If result set is not positioned on a row.
     */
    private void ensureHasCurrentRow() throws SQLException {
        if (curr == null)
            throw new SQLException("Result set is not positioned on a row.");
    }

    /**
     * @return Is Query flag.
     */
    public boolean isQuery() {
        return isQry;
    }

    /**
     * @return Update count.
     */
    public long updateCount() {
        return updCnt;
    }

    /**
     * @param rows query result.
     * @return update counter, if found.
     * @throws SQLException if getting an update counter from result proved to be impossible.
     */
    private static long updateCounterFromQueryResult(List<List<?>> rows) throws SQLException {
        if (F.isEmpty(rows))
            return -1;

        if (rows.size() != 1)
            throw new SQLException("Expected fetch size of 1 for update operation.");

        List<?> row = rows.get(0);

        if (row.size() != 1)
            throw new SQLException("Expected row size of 1 for update operation.");

        Object objRes = row.get(0);

        if (!(objRes instanceof Long))
            throw new SQLException("Unexpected update result type.");

        return (Long)objRes;
    }
}