| gvSIG desktop 1

/*

 * Created on 11-mar-2005

 *

 * 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.jdbc.postgis;

import java.nio.ByteBuffer;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.SQLException;

import java.sql.Statement;

import java.sql.Types;

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

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

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

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

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

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

import com.iver.cit.gvsig.fmap.drivers.DBLayerDefinition;

import com.iver.cit.gvsig.fmap.drivers.IFeatureIterator;

import com.iver.cit.gvsig.fmap.drivers.WKBParser2;

import com.iver.cit.gvsig.fmap.drivers.XTypes;

/**

 * @author FJP

 * 

 * TODO To change the template for this generated type comment go to Window -

 * Preferences - Java - Code Generation - Code and Comments

 */

public class PostGisFeatureIterator implements IFeatureIterator {

        private static int FETCH_SIZE = 5000;

        private WKBParser2 parser = new WKBParser2();

        private ResultSetMetaData metaData = null;

        ResultSet rs;

        Statement st;

        String strAux;

        IGeometry geom;

        int numColumns;

        Value[] regAtt;

        /**

         * Array con la correspondencia entre un campo de la consulta y el campo

         * dentro de regAtt

         */

        int[] relIds;

        private DBLayerDefinition lyrDef;

        int numReg = 0;

        int idFieldID = -1;

        String cursorName;

        /**

         * @throws SQLException

         * @throws SQLException

         * 

         */

        public PostGisFeatureIterator(Connection conn, String cursorName, String sql)

                        throws SQLException {

                // Basado en 0, es decir, no cuenta el campo

                // de geometria

                // Debe ser forward only

                st = conn.createStatement();

                st.execute("BEGIN");

                st.execute("declare " + cursorName + " binary cursor for " + sql);

                this.rs = st.executeQuery("fetch forward " + FETCH_SIZE + " in "

                                + cursorName);

                this.cursorName = cursorName;

                numColumns = rs.getMetaData().getColumnCount();

                metaData = rs.getMetaData();

                numReg = 0;

        }

        /*

         * (non-Javadoc)

         * 

         * @see com.iver.cit.gvsig.fmap.drivers.jdbc.GeometryIterator#hasNext()

         */

        public boolean hasNext() throws DriverException {

                try {

                        if (numReg > 0)

                                if ((numReg % FETCH_SIZE) == 0) {

                                        rs = st.executeQuery("fetch forward " + FETCH_SIZE + " in "

                                                        + cursorName);

                                        // System.out.println("ejecutando la query otra vez");

                                }

                        // System.out.println("hasNext con numReg=" + numReg);

                        if (rs.next())

                                return true;

                        else {

                                closeIterator();

                                return false;

                        }

                } catch (SQLException e) {

                        throw new DriverException(e);

                }

        }

        /*

         * (non-Javadoc)

         * 

         * @see com.iver.cit.gvsig.fmap.drivers.jdbc.GeometryIterator#next()

         */

        public IFeature next() throws DriverException {

                byte[] data;

                try {

                        data = rs.getBytes(1);

                        geom = parser.parse(data);

                        for (int fieldId = 2; fieldId <= numColumns; fieldId++) {

                                Value val = XTypes.getValue(rs, fieldId);

                                regAtt[relIds[fieldId - 2]] = val;

                        }

                        // TODO: Aqu? habr?a que usar una Factor?a.

                        IFeature feat = null;

                        if (idFieldID != -1) {

                                String theID = regAtt[lyrDef.getIdFieldID()].toString();

                                feat = new DefaultFeature(geom, regAtt, theID);

                        }

                        else

                        {

                                // feat = new DefaultFeature(geom, regAtt);

                                throw new DriverException("Fallo al crear una Feature sin ID");

                        }

                        numReg++;

                        return feat;

                } catch (SQLException e) {

                        throw new DriverException(e);

                }

        }

        /*

         * (non-Javadoc)

         * 

         * @see com.iver.cit.gvsig.fmap.drivers.IFeatureIterator#closeIterator()

         */

        public void closeIterator() throws DriverException {

                try {

                        numReg = 0;

                        // st.execute("CLOSE " + cursorName);

                        // st.execute("COMMIT");

                        rs.close();

                } catch (SQLException e) {

                        throw new DriverException(e);

                }

                // st.execute("COMMIT");

                // st.close();

        }

        public void setLyrDef(DBLayerDefinition lyrDef) {

                this.lyrDef = lyrDef;

                // Aunque no nos hayan pedido todos los campos, devolveremos

                // tantos atributos como la capa tiene. Eso s?, puestos a null

                regAtt = new Value[lyrDef.getFieldNames().length];

                relIds = new int[numColumns - 1];

                try {

                        for (int i = 2; i <= metaData.getColumnCount(); i++) {

                                int idRel = lyrDef.getFieldIdByName(metaData.getColumnName(i));

                                if (idRel == -1)

                                {

                                        throw new RuntimeException("No se ha encontrado el nombre de campo " + metaData.getColumnName(i));

                                }

                                relIds[i - 2] = idRel;

                                if (lyrDef.getFieldID().equals(metaData.getColumnName(i))) {

                                        idFieldID = i;

                                        // break;

                                }

                        }

                } catch (SQLException e) {

                        // Si no est?, no pasa nada

                        e.printStackTrace();

                }

        }

}