Application: gvSIG desktop

package com.hardcode.gdbms.engine.data.db;

import com.hardcode.gdbms.engine.data.driver.DriverException;

import com.hardcode.gdbms.engine.data.driver.ReadAccess;

import com.hardcode.gdbms.engine.values.Value;

import com.hardcode.gdbms.engine.values.ValueFactory;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.sql.Types;

/**

 *

 */

public class JDBCSupport implements ReadAccess {

    private ResultSet resultSet;

    private int rowCount = -1;

    /**

     * Creates a new JDBCSupport object.

     *

     * @param r DOCUMENT ME!

     */

    public JDBCSupport(ResultSet r) {

        resultSet = r;

    }

    /**

     * @see com.hardcode.gdbms.engine.data.driver.ReadAccess#getFieldValue(long,

     *      int)

     */

    public Value getFieldValue(long rowIndex, int fieldId)

        throws DriverException {

        Value value = null;

        try {

            fieldId += 1;

            resultSet.absolute((int) rowIndex + 1);

            int type = resultSet.getMetaData().getColumnType(fieldId);

            switch (type) {

            case Types.BIGINT:

                value = ValueFactory.createValue(resultSet.getLong(fieldId));

                break;

            case Types.BIT:

            case Types.BOOLEAN:

                value = ValueFactory.createValue(resultSet.getBoolean(fieldId));

                break;

            case Types.CHAR:

            case Types.VARCHAR:

            case Types.LONGVARCHAR:

                value = ValueFactory.createValue(resultSet.getString(fieldId));

                break;

            case Types.DATE:

                value = ValueFactory.createValue(resultSet.getDate(fieldId));

                break;

            case Types.DECIMAL:

            case Types.NUMERIC:

            case Types.FLOAT:

            case Types.DOUBLE:

                value = ValueFactory.createValue(resultSet.getDouble(fieldId));

                break;

            case Types.INTEGER:

                value = ValueFactory.createValue(resultSet.getInt(fieldId));

                break;

            case Types.REAL:

                value = ValueFactory.createValue(resultSet.getFloat(fieldId));

                break;

            case Types.SMALLINT:

                value = ValueFactory.createValue(resultSet.getShort(fieldId));

                break;

            case Types.TINYINT:

                value = ValueFactory.createValue(resultSet.getByte(fieldId));

                break;

            case Types.BINARY:

            case Types.VARBINARY:

            case Types.LONGVARBINARY:

                value = ValueFactory.createValue(resultSet.getBytes(fieldId));

                break;

            case Types.TIMESTAMP:

                value = ValueFactory.createValue(resultSet.getTimestamp(fieldId));

                break;

            case Types.TIME:

                value = ValueFactory.createValue(resultSet.getTime(fieldId));

                break;

            default:

                value = ValueFactory.createValue(resultSet.getString(fieldId));

            }

        } catch (SQLException e) {

            throw new DriverException(e);

        }

                return (value == null)?ValueFactory.createNullValue():value;

    }

    /**

     * @see com.hardcode.gdbms.engine.data.driver.ReadAccess#getFieldCount()

     */

    public int getFieldCount() throws DriverException {

        try {

            return resultSet.getMetaData().getColumnCount();

        } catch (SQLException e) {

            throw new DriverException(e);

        }

    }

    /**

     * @see com.hardcode.gdbms.engine.data.driver.ReadAccess#getFieldName(int)

     */

    public String getFieldName(int fieldId) throws DriverException {

        try {

            return resultSet.getMetaData().getColumnName(fieldId + 1);

        } catch (SQLException e) {

            throw new DriverException(e);

        }

    }

    /**

     * @see com.hardcode.gdbms.engine.data.driver.ReadAccess#getRowCount()

     */

    public long getRowCount() throws DriverException {

        try {

            if (rowCount == -1) {

                resultSet.last();

                rowCount = resultSet.getRow();

            }

            return rowCount;

        } catch (SQLException e) {

            throw new RuntimeException(e);

        }

    }

    /**

     * @see com.hardcode.gdbms.engine.data.driver.ReadAccess#getFieldType(int)

     */

    public int getFieldType(int i) throws DriverException {

        try {

            return resultSet.getMetaData().getColumnType(i);

        } catch (SQLException e) {

            throw new DriverException(e);

        }

    }

    /**

     * DOCUMENT ME!

     *

     * @throws SQLException

     */

    public void close() throws SQLException {

        resultSet.close();

    }

    /**

     * DOCUMENT ME!

     *

     * @return DOCUMENT ME!

     */

    public ResultSet getResultSet() {

        return resultSet;

    }

    /**

     * DOCUMENT ME!

     *

     * @param con DOCUMENT ME!

     * @param sql DOCUMENT ME!

     *

     * @return DOCUMENT ME!

     *

     * @throws SQLException DOCUMENT ME!

     */

    public static JDBCSupport open(Connection con, String sql)

        throws SQLException {

        Statement st = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,

                ResultSet.CONCUR_READ_ONLY);

        ResultSet res = st.executeQuery(sql);

        return new JDBCSupport(res);

    }

    /**

     * DOCUMENT ME!

     *

     * @param fields DOCUMENT ME!

     * @param tableName DOCUMENT ME!

     * @param where DOCUMENT ME!

     *

     * @return DOCUMENT ME!

     */

    private static String buildQuery(String[] fields, String tableName,

        String where) {

        String res = "select ";

        if (fields.length > 0) {

            res += fields[0];

        }

        for (int i = 1; i < fields.length; i++) {

            res += ("," + fields[i]);

        }

        res += (" from " + tableName);

        if (where != null) {

            res += (" where " + where);

        }

        return res;

    }

    /**

     * Executes a query with the 'con' connection

     *

     * @param con connection

     * @param sql instruction to execute

     *

     * @throws SQLException if execution fails

     */

    public static void execute(Connection con, String sql)

        throws SQLException {

        Statement st = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,

                ResultSet.CONCUR_UPDATABLE);

        st.execute(sql);

    }

}