| gvSIG desktop 1

/* gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

package com.iver.cit.gvsig.fmap.drivers;

import java.awt.geom.Rectangle2D;

import java.sql.DatabaseMetaData;

import java.sql.Driver;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.SQLException;

import java.sql.Statement;

import java.sql.Types;

import java.util.Hashtable;

import java.util.TreeMap;

import org.apache.log4j.Logger;

import com.hardcode.gdbms.driver.exceptions.BadFieldDriverException;

import com.hardcode.gdbms.driver.exceptions.ReadDriverException;

import com.hardcode.gdbms.driver.exceptions.ReloadDriverException;

import com.hardcode.gdbms.engine.data.DataSourceFactory;

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

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

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

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

import com.iver.cit.gvsig.exceptions.expansionfile.ExpansionFileReadException;

import com.iver.cit.gvsig.fmap.DriverJdbcNotFoundExceptionType;

import com.iver.cit.gvsig.fmap.MapContext;

import com.iver.cit.gvsig.fmap.Messages;

import com.iver.cit.gvsig.fmap.core.IFeature;

import com.iver.cit.gvsig.fmap.core.IGeometry;

import com.iver.cit.gvsig.fmap.drivers.db.utils.ConnectionWithParams;

import com.iver.cit.gvsig.fmap.drivers.db.utils.SingleVectorialDBConnectionManager;

import com.iver.cit.gvsig.fmap.layers.SelectableDataSource;

import com.iver.cit.gvsig.fmap.layers.XMLException;

import com.iver.utiles.XMLEntity;

import com.iver.utiles.swing.JPasswordDlg;

/**

 * Clase abstracta qu

 */

public abstract class DefaultJDBCDriver implements IVectorialJDBCDriver, ObjectDriver {

    private static Logger logger = Logger.getLogger(SelectableDataSource.class.getName());

    protected static Hashtable poolPassw = new Hashtable();

    protected IConnection conn;

    // protected String tableName;

    // protected String whereClause;

    // protected String fields;

    // protected String sqlOrig;

    protected DBLayerDefinition lyrDef = null;

    protected ResultSet rs;

    protected boolean bCursorActivo = false;

    protected Statement st;

    protected int numReg=-1;

    protected Rectangle2D fullExtent = null;

    // protected String strFID_FieldName;

    // protected String idFID_FieldName;

    protected Hashtable hashRelate;

    protected ResultSetMetaData metaData = null;

    protected Rectangle2D workingArea;

    protected String driverClass;

    protected String userName;

    // protected String dbUrl;

    protected String className;

    protected String catalogName;

    protected String tableName;

    protected String[] fields;

    protected String FIDfield;

    protected String geometryField;

    protected String whereClause;

    protected String strSRID;

        //private double flatness;

    protected String host, port, dbName, connName;

    private MapContext mapContext = null;

    abstract public void setData(IConnection conn, DBLayerDefinition lyrDef);

        /**

         * @return devuelve la Conexi?n a la base de datos, para que

         * el usuario pueda hacer la consulta que quiera, si lo desea.

         * Por ejemplo, esto puede ser ?til para abrir un cuadro de dialogo

         * avanazado y lanzar peticiones del tipo "Devuelveme un buffer

         * a las autopistas", y con el resultset que te venga, escribir

         * un shape, o cosas as?.

         */

        public IConnection getConnection()

        {

            return conn;

        }

        public String[] getFields()

        {

        /* StringTokenizer tokenizer = new StringTokenizer(fields, ",");

        String[] arrayFields = new String[tokenizer.countTokens()];

        int i=0;

        while (tokenizer.hasMoreTokens())

        {

            arrayFields[i] = tokenizer.nextToken();

            i++;

        }

            return arrayFields; */

        return lyrDef.getFieldNames();

        }

    /**

     * First, the geometry field. After, the rest of fields

     * @return

     */

    public String getTotalFields()

    {

        String strAux = getGeometryField(getLyrDef().getFieldGeometry());

        String[] fieldNames = getLyrDef().getFieldNames();

        for (int i=0; i< fieldNames.length; i++)

        {

            strAux = strAux + ", " + fieldNames[i];

        }

        return strAux;

    }

        /* (non-Javadoc)

         * @see com.iver.cit.gvsig.fmap.drivers.VectorialDatabaseDriver#getWhereClause()

         */

        public String getWhereClause()

        {

            return lyrDef.getWhereClause().toUpperCase();

        }

        public String getTableName()

        {

            return lyrDef.getTableName();

        }

        /**

         * @throws DriverIOException

         * @throws DriverException

         * @see com.iver.cit.gvsig.fmap.layers.ReadableVectorial#getShapeCount()

         */

        public int getShapeCount() throws ReadDriverException {

                    if (numReg == -1)

                    {

                        try

                    {

                            Statement s = ((ConnectionJDBC)conn).getConnection().createStatement();

                            ResultSet r = s.executeQuery("SELECT COUNT(*) AS NUMREG FROM " + lyrDef.getTableName() + " " + getCompleteWhere());

                            r.next();

                            numReg = r.getInt(1);

                            System.err.println("numReg = " + numReg);

                    }

                        catch (SQLException e)

                        {

                            throw new ReadDriverException(getName(),e);

                        }

                    }

            return numReg;

        }

         public Rectangle2D getFullExtent() throws ExpansionFileReadException, ReadDriverException{

                // Por defecto recorremos todas las geometrias.

                // Las bases de datos como PostGIS pueden y deben

                // sobreescribir este m?todo.

                if (fullExtent == null)

                {

//                    try

//                    {

                        IFeatureIterator itGeom = getFeatureIterator("SELECT " +

                                getGeometryField(getLyrDef().getFieldGeometry()) + ", " + getLyrDef().getFieldID() + " FROM " +

                                getLyrDef().getComposedTableName() +  " " + getCompleteWhere());

                        IGeometry geom;

                        int cont = 0;

                        while (itGeom.hasNext())

                        {

                            geom = itGeom.next().getGeometry();

                            if (cont==0)

                                fullExtent = geom.getBounds2D();

                            else

                                fullExtent.add(geom.getBounds2D());

                            cont++;

                        }

//                    }

//                    catch (DriverException e) {

//                        // TODO Auto-generated catch block

//                        e.printStackTrace();

//                    }

                }

                return fullExtent;

            }

        /**

         * @see com.iver.cit.gvsig.fmap.layers.ReadableVectorial#getShapeType()

         */

        public int getShapeType() {

        /* IGeometry geom;

        if (shapeType == -1)

        {

                shapeType = FShape.MULTI;

                try {

                        geom = getShape(0);

                        if (geom != null)

                                shapeType = geom.getGeometryType();

                } catch (IOException e) {

                        // e.printStackTrace();

                }

        }

        return shapeType; */

                return lyrDef.getShapeType();

        }

        public int getFieldType(int idField) throws ReadDriverException{

            String str = "";

            try {

                int i = idField + 2; // idField viene basado en 1, y

                                        // adem?s nos saltamos el campo de geometry

                str = metaData.getColumnClassName(i);

            if (metaData.getColumnType(i) == Types.VARCHAR)

                return Types.VARCHAR;

                    if (metaData.getColumnType(i) == Types.FLOAT)

                        return Types.FLOAT;

                    if (metaData.getColumnType(i) == Types.DOUBLE)

                        return Types.DOUBLE;

                    if (metaData.getColumnType(i) == Types.INTEGER)

                        return Types.INTEGER;

                    if (metaData.getColumnType(i) == Types.SMALLINT)

                        return Types.SMALLINT;

                    if (metaData.getColumnType(i) == Types.TINYINT)

                        return Types.TINYINT;

                    if (metaData.getColumnType(i) == Types.BIGINT)

                        return Types.BIGINT;

                    if (metaData.getColumnType(i) == Types.BIT)

                        return Types.BIT;

                    if (metaData.getColumnType(i) == Types.DATE)

                        return Types.DATE;

            if (metaData.getColumnType(i) == Types.DECIMAL)

                return Types.DOUBLE;

            if (metaData.getColumnType(i) == Types.NUMERIC)

                return Types.DOUBLE;

            if (metaData.getColumnType(i) == Types.DATE)

                return Types.DATE;

            if (metaData.getColumnType(i) == Types.TIME)

                return Types.TIME;

            if (metaData.getColumnType(i) == Types.TIMESTAMP)

                return Types.TIMESTAMP;

            } catch (SQLException e) {

                    throw new BadFieldDriverException(getName(),e,String.valueOf(idField));

            }

            return Types.OTHER;

        // throw new com.hardcode.gdbms.engine.data.driver.DriverException("Tipo no soportado: " + str);

        }

    /**

     * Obtiene el valor que se encuentra en la fila y columna indicada

     * Esta es la implementaci?n por defecto. Si lo del absolute

     * no va bien, como es el caso del PostGis, el driver lo

     * tiene que reimplementar

     *

     * @param rowIndex fila

     * @param fieldId columna

     *

     * @return subclase de Value con el valor del origen de datos

     *

     * @throws DriverException Si se produce un error accediendo al DataSource

     */

    public Value getFieldValue(long rowIndex, int idField)

        throws ReadDriverException

        {

                int i = (int) (rowIndex + 1);

                int fieldId = idField+2;

                try {

                    rs.absolute(i);

                if (metaData.getColumnType(fieldId) == Types.VARCHAR)

                {

                    String strAux = rs.getString(fieldId);

                    if (strAux == null) strAux = "";

                    return ValueFactory.createValue(strAux);

                }

                        if (metaData.getColumnType(fieldId) == Types.FLOAT)

                            return ValueFactory.createValue(rs.getFloat(fieldId));

                        if (metaData.getColumnType(fieldId) == Types.DOUBLE)

                            return ValueFactory.createValue(rs.getDouble(fieldId));

                        if (metaData.getColumnType(fieldId) == Types.INTEGER)

                            return ValueFactory.createValue(rs.getInt(fieldId));

                        if (metaData.getColumnType(fieldId) == Types.BIGINT)

                            return ValueFactory.createValue(rs.getLong(fieldId));

                        if (metaData.getColumnType(fieldId) == Types.BIT)

                            return ValueFactory.createValue(rs.getBoolean(fieldId));

                        if (metaData.getColumnType(fieldId) == Types.DATE)

                            return ValueFactory.createValue(rs.getDate(fieldId));

                } catch (SQLException e) {

                throw new BadFieldDriverException(getName(),e,String.valueOf(fieldId));

                }

                return null;

        }

    /**

     * Obtiene el n?mero de campos del DataSource

     *

     * @return

     *

     * @throws DriverException Si se produce alg?n error accediendo al

     *         DataSource

     */

    public int getFieldCount() throws ReadDriverException

    {

        try {

            // Suponemos que el primer campo es el de las geometries, y no lo

            // contamos

            return rs.getMetaData().getColumnCount()-1;

        } catch (SQLException e) {

            throw new ReadDriverException(getName(),e);

        }

    }

    /**

     * Devuelve el nombre del campo fieldId-?simo

     *

     * @param fieldId ?ndice del campo cuyo nombre se quiere obtener

     *

     * @return

     * @throws com.hardcode.gdbms.engine.data.driver.DriverException

     *

     * @throws DriverException Si se produce alg?n error accediendo al

     *         DataSource

     */

    public String getFieldName(int fieldId) throws ReadDriverException

    {

        try {

            return rs.getMetaData().getColumnName(fieldId+2);

        } catch (SQLException e) {

            throw new ReadDriverException(getName(),e);

        }

    }

    /**

     * Obtiene el n?mero de registros del DataSource

     *

     * @return

     * @throws ReadDriverException

     *

     * @throws DriverException Si se produce alg?n error accediendo al

     *         DataSource

     */

    public long getRowCount() throws ReadDriverException{

        return getShapeCount();

    }

    public void close() {

    }

    /**

     * Recorre el recordset creando una tabla Hash que usaremos para

     * relacionar el n?mero de un registro con su identificador ?nico.

     * Debe ser llamado en el setData justo despu?s de crear el recorset

     * principal

     * @throws SQLException

     */

    protected void doRelateID_FID() throws SQLException

    {

        hashRelate = new Hashtable();

        String strSQL = "SELECT " + getLyrDef().getFieldID() + " FROM " + getLyrDef().getComposedTableName()

        + " " + getCompleteWhere() + " ORDER BY " + getLyrDef().getFieldID();

        Statement s = ((ConnectionJDBC)getConnection()).getConnection().createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);

        ResultSet r = s.executeQuery(strSQL);

        int id=0;

        int gid;

        int index = 0;

        while (r.next())

        {

            String aux = r.getString(1);

            Value val = ValueFactory.createValue(aux);

            hashRelate.put(val, new Integer(index));

            System.out.println("ASOCIANDO CLAVE " + aux + " CON VALOR " + index);

            index++;

        }

        numReg = index;

        r.close();

        // rs.beforeFirst();

    }

    /* (non-Javadoc)

     * @see com.iver.cit.gvsig.fmap.drivers.VectorialDatabaseDriver#getRowIndexByFID(java.lang.Object)

     */

    public int getRowIndexByFID(IFeature FID)

    {

        int resul;

        // Object obj = FID.getAttribute(lyrDef.getIdFieldID());

        String theId = FID.getID();

        Value aux = ValueFactory.createValue(theId);

        // System.err.println("Mirando si existe " + aux.toString());

        if (hashRelate.containsKey(aux))

        {

                Integer rowIndex = (Integer) hashRelate.get(aux);

                resul = rowIndex.intValue();

                // System.err.println("Row asociada a " + aux.toString() + ":" + resul);

                return resul;

        }

        else

                return -1;

    }

    /* (non-Javadoc)

     * @see com.iver.cit.gvsig.fmap.drivers.VectorialDatabaseDriver#setXMLEntity(com.iver.utiles.XMLEntity)

     */

    public void setXMLEntity(XMLEntity xml) throws XMLException

    {

        className = xml.getStringProperty("className");

        // dbUrl = xml.getStringProperty("dbURL");

        catalogName = xml.getStringProperty("catalog");

        userName =xml.getStringProperty("username");

        driverClass =xml.getStringProperty("driverclass");

        tableName = xml.getStringProperty("tablename");

        fields = xml.getStringArrayProperty("fields");

        FIDfield = xml.getStringProperty("FID");

        geometryField = xml.getStringProperty("THE_GEOM");

        whereClause = xml.getStringProperty("whereclause");

        strSRID = xml.getStringProperty("SRID");

        host = xml.getStringProperty("host");

        port = xml.getStringProperty("port");

        dbName = xml.getStringProperty("dbName");

        connName = xml.getStringProperty("connName");

        if (xml.contains("minXworkArea"))

        {

            double x = xml.getDoubleProperty("minXworkArea");

            double y = xml.getDoubleProperty("minYworkArea");

            double H = xml.getDoubleProperty("HworkArea");

            double W = xml.getDoubleProperty("WworkArea");

            workingArea = new Rectangle2D.Double(x,y,W,H);

        }

        DBLayerDefinition lyrDef = new DBLayerDefinition();

        lyrDef.setCatalogName(catalogName);

        lyrDef.setTableName(tableName);

        lyrDef.setFieldGeometry(geometryField);

        lyrDef.setFieldNames(fields);

        lyrDef.setFieldID(FIDfield);

        lyrDef.setWhereClause(whereClause);

        // lyrDef.setClassToInstantiate(driverClass);

        if (workingArea != null)

            lyrDef.setWorkingArea(workingArea);

        lyrDef.setSRID_EPSG(strSRID);

        setLyrDef(lyrDef);

    }

    public void load() throws ReadDriverException {

            try {

            Class.forName(driverClass);

            String _drvName = getName();

            String keyPool = _drvName.toLowerCase() + "_" + host.toLowerCase()

            + "_" + port + "_" + dbName.toLowerCase()

            + "_" + userName.toLowerCase();

            IConnection newConn = null;

            String clave = null;

            ConnectionWithParams cwp = null;

            if (poolPassw.containsKey(keyPool)) {

                clave = (String) poolPassw.get(keyPool);

                cwp = SingleVectorialDBConnectionManager.instance().getConnection(

                                         _drvName, userName, clave, connName,

                                         host, port, dbName, true);

            } else {

                cwp = SingleVectorialDBConnectionManager.instance().getConnection(

                                             _drvName, userName, null, connName,

                                             host, port, dbName, false);

                if (cwp.isConnected()) {

                        poolPassw.put(keyPool, cwp.getPw());

                } else {

                    JPasswordDlg dlg = new JPasswordDlg();

                    String strMessage = Messages.getString("conectar_jdbc");

                    String strPassword = Messages.getString("password");

                    dlg.setMessage(strMessage

                                    + " ["

                                    + _drvName + ", "

                                    + host + ", "

                                    + port + ", "

                                    + dbName + ", "

                                    + userName + "]. "

                                    + strPassword

                                    + "?");

                    dlg.show();

                    clave = dlg.getPassword();

                    if (clave == null)

                        return;

                    poolPassw.put(keyPool, clave);

                    cwp.connect(clave);

                }

            }

            newConn = cwp.getConnection();

            ((ConnectionJDBC)newConn).getConnection().setAutoCommit(false);

            DBLayerDefinition lyrDef = new DBLayerDefinition();

            if (getLyrDef() == null) {

                    lyrDef.setCatalogName(catalogName);

                    lyrDef.setTableName(tableName);

                    lyrDef.setFieldNames(fields);

                    lyrDef.setFieldID(FIDfield);

                    lyrDef.setFieldGeometry(geometryField);

                    lyrDef.setWhereClause(whereClause);

                    // lyrDef.setClassToInstantiate(driverClass);

                    if (workingArea != null)

                        lyrDef.setWorkingArea(workingArea);

                    lyrDef.setSRID_EPSG(strSRID);

            } else {

                    lyrDef = getLyrDef();

            }

            setData(newConn, lyrDef);

        } catch (ClassNotFoundException e) {

//            logger.debug(e);

//            DriverJdbcNotFoundExceptionType type =

//                    new DriverJdbcNotFoundExceptionType();

//            type.setDriverJdbcClassName(driverClass);

//            type.setLayerName(this.getTableName());

            throw new ReadDriverException(getName(),e);

        } catch (SQLException e) {

                throw new ReadDriverException(getName(),e);

                } catch (DBException e) {

                        throw new ReadDriverException(getName(),e);

                }

    }

    /* (non-Javadoc)

     * @see com.iver.cit.gvsig.fmap.drivers.VectorialDatabaseDriver#getXMLEntity()

     */

    public XMLEntity getXMLEntity()

    {

        XMLEntity xml = new XMLEntity();

        xml.putProperty("className",this.getClass().getName());

        try {

                 DatabaseMetaData metadata = ((ConnectionJDBC)getConnection()).getConnection().getMetaData();

            xml.putProperty("catalog", getLyrDef().getCatalogName());

            // TODO: NO DEBEMOS GUARDAR EL NOMBRE DE USUARIO Y CONTRASE?A

            // AQUI. Hay que utilizar un pool de conexiones

            // y pedir al usuario que conecte a la base de datos

            // en la primera capa. En el resto, usar la conexi?n

            // creada con anterioridad.

            String userName = metadata.getUserName();

            int aux = userName.indexOf("@");

            if (aux != -1)

                userName = userName.substring(0,aux);

            xml.putProperty("username", userName);

            Driver drv = DriverManager.getDriver(metadata.getURL());

            // System.out.println(drv.getClass().getName());

            xml.putProperty("driverclass", drv.getClass().getName());

            xml.putProperty("tablename", getTableName());

            xml.putProperty("fields", lyrDef.getFieldNames());

            xml.putProperty("FID", lyrDef.getFieldID());

            xml.putProperty("THE_GEOM", lyrDef.getFieldGeometry());

            xml.putProperty("whereclause", getWhereClause());

            xml.putProperty("SRID", lyrDef.getSRID_EPSG());

            ConnectionWithParams cwp =

                    SingleVectorialDBConnectionManager.instance().findConnection(getConnection());

            xml.putProperty("host", cwp.getHost());

            xml.putProperty("port", cwp.getPort());

            xml.putProperty("dbName", cwp.getDb());

            xml.putProperty("connName", cwp.getName());

            if (getWorkingArea() != null)

            {

                xml.putProperty("minXworkArea", getWorkingArea().getMinX());

                xml.putProperty("minYworkArea", getWorkingArea().getMinY());

                xml.putProperty("HworkArea", getWorkingArea().getHeight());

                xml.putProperty("WworkArea", getWorkingArea().getWidth());

            }

        } catch (SQLException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        return xml;

    }

    /**

     * @see com.iver.cit.gvsig.fmap.drivers.VectorialJDBCDriver#setWorkingArea(java.awt.geom.Rectangle2D)

     */

    public void setWorkingArea(Rectangle2D rect) {

        this.workingArea = rect;

    }

    /**

     * @see com.iver.cit.gvsig.fmap.drivers.VectorialJDBCDriver#getWorkingArea()

     */

    public Rectangle2D getWorkingArea() {

        return workingArea;

    }

    /* (non-Javadoc)

     * @see com.hardcode.gdbms.engine.data.driver.GDBMSDriver#setDataSourceFactory(com.hardcode.gdbms.engine.data.DataSourceFactory)

     */

    public void setDataSourceFactory(DataSourceFactory arg0) {

        // TODO Auto-generated method stub

    }

    /**

     * @return Returns the lyrDef.

     */

    public DBLayerDefinition getLyrDef() {

        return lyrDef;

    }

    /**

     * @param lyrDef The lyrDef to set.

     */

    public void setLyrDef(DBLayerDefinition lyrDef) {

        this.lyrDef = lyrDef;

    }

    abstract public String getSqlTotal();

    /**

     * @return Returns the completeWhere. WITHOUT order by clause!!

     */

    abstract public String getCompleteWhere();

    /* (non-Javadoc)

     * @see com.iver.cit.gvsig.fmap.drivers.VectorialDriver#reLoad()

     */

    public void reload() throws ReloadDriverException

    {

                try {

                    if (conn == null) this.load();

                        ((ConnectionJDBC)conn).getConnection().commit();

                    setData(conn, lyrDef);

                } catch (SQLException e) {

                        throw new ReloadDriverException(getName(),e);

                } catch (ReadDriverException e) {

                        throw new ReloadDriverException(getName(),e);

                }

    }

    public int getFieldWidth(int fieldId)

    {

            int i = -1;

            try {

                    int aux = fieldId + 2; // idField viene basado en 1, y

                        i = rs.getMetaData().getColumnDisplaySize(aux);

                } catch (SQLException e) {

                        e.printStackTrace();

                }

                // SUN define que getColumnDisplaySize devuelve numeros negativos cuando el campo es de tipo Text o Vartext

                // sin ancho. Nosotros vamos a devolver 255 para que fucione, por lo menos al exportar a DBF.

                // Nota: Si se truncan cadenas, este es el sitio que lo provoca.

                if (i <0) i=255;

                return i;

    }

//        public void setFlatness(double flatness) {

//                this.flatness = flatness;

//        }

    // -----------------------------------------------------------

    // ----  EXT JDBC NUEVA                           ---

    // -----------------------------------------------------------

    /**

     * Gets the drivers connection string given its parameters (this can be different for

     * different driver, so it should be overwritten in that case.)

     */

    public String getConnectionString(

                    String host,

                    String port,

                    String dbname,

                    String user,

                    String pw) {

                String resp = getConnectionStringBeginning() + "//" + host.toLowerCase();

                if (dbname.trim().length() > 0) {

                        resp += ":" + port;

                } else {

                        resp += ":" + getDefaultPort();

                }

                resp += "/" + dbname.toLowerCase();

                return resp;

    }

    /**

     * Gets available table names. Should be overwritten by subclasses if its

     * not compatible or if it can be refined

     *

     * @param conn connection object

     * @param catalog catalog name

     * @return array of strings with available table names

     * @throws SQLException

     */

    public String[] getTableNames(IConnection conn, String catalog) throws DBException {

            try {

            DatabaseMetaData dbmd;

                        dbmd = ((ConnectionJDBC)conn).getConnection().getMetaData();

        String[] types = {"TABLE", "VIEW"};

                ResultSet rs = dbmd.getTables(catalog, null, null, types);

                TreeMap ret = new TreeMap();

                while (rs.next()){

                        ret.put(rs.getString("TABLE_NAME"), rs.getString("TABLE_NAME"));

                }

                rs.close();

                return (String[]) ret.keySet().toArray(new String[0]);

            } catch (SQLException e) {

                        throw new DBException(e);

                }

    }

    /**

     *       Gets all field names of a given table

     * @param conn connection object

     * @param table_name table name

     * @return all field names of the given table

     * @throws SQLException

     */

    public String[] getAllFields(IConnection conn, String table_name) throws DBException {

            try {

                Statement st = ((ConnectionJDBC)conn).getConnection().createStatement();

                ResultSet rs = st.executeQuery("select * from " + table_name + " LIMIT 1");

                ResultSetMetaData rsmd = rs.getMetaData();

                String[] ret = new String[rsmd.getColumnCount()];

                for (int i = 0; i < ret.length; i++) {

                        ret[i] = rsmd.getColumnName(i+1);

                }

                rs.close(); st.close();

                return ret;

            } catch (SQLException e) {

                        throw new DBException(e);

                }

    }

    /**

     *       Gets all field type names of a given table

     * @param conn connection object

     * @param table_name table name

     * @return all field type names of the given table

     * @throws SQLException

     */

    public String[] getAllFieldTypeNames(IConnection conn, String table_name) throws DBException {

try {

                Statement st = ((ConnectionJDBC)conn).getConnection().createStatement();

                ResultSet rs = st.executeQuery("select * from " + table_name + " LIMIT 1");

                ResultSetMetaData rsmd = rs.getMetaData();

                String[] ret = new String[rsmd.getColumnCount()];

                for (int i = 0; i < ret.length; i++) {

                        ret[i] = rsmd.getColumnTypeName(i+1);

                }

                rs.close(); st.close();

                return ret;

} catch (SQLException e) {

        throw new DBException(e);

}

    }

    /**

     * Gets the table's possible id fields. By default, all fields can be id.

     * It should be overwritten by subclasses.

     *

     * @param conn conenction object

     * @param table_name table name

     * @return the table's possible id fields

     * @throws SQLException

     */

    public String[] getIdFieldsCandidates(IConnection conn, String table_name) throws DBException {

            return getAllFields(conn, table_name);

    }

    /**

     * Gets the table's possible geometry fields. By default, all fields can be geometry

     * fields. It should be overwritten by subclasses.

     *

     * @param conn conenction object

     * @param table_name table name

     * @return the table's possible geometry fields

     * @throws SQLException

     */

    public String[] getGeometryFieldsCandidates(IConnection conn, String table_name) throws DBException {

            return getAllFields(conn, table_name);

    }

    /**

     * Tells if it's an empty table (with no records)

     * @param conn conenction object

     * @param tableName rtable name

     * @return whether it's an empty table (with no records) or not

     */

        public boolean isEmptyTable(IConnection conn, String tableName) {

                boolean res = true;

                try {

                        Statement st = ((ConnectionJDBC)conn).getConnection().createStatement();

                        ResultSet rs = null;

                        rs = st.executeQuery("select * from " + tableName + " LIMIT 1");

                        res = !rs.next();

                        rs.close(); st.close();

                } catch (Exception ex) {

                        res = true;

                }

                return res;

        }

        /**

         * Utility method to allow the driver to do something with the geometry field.

         * By default does nothing.

         *

         * @param flds user-selected fields

         * @param geomField geometry field

         * @return new user-selected fields

         */

        public String[] manageGeometryField(String[] flds, String geomField) {

                return flds;

        }

        /**

         * Empty method called when the layer is going to be removed from the view.

         * Subclasses can overwrite it if needed.

         *

         */

        public void remove() {

        }

}