| 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 org.gvsig.remoteClientOld.wms;

import java.io.IOException;

import java.net.URL;

import java.util.ArrayList;

import java.util.Iterator;

import org.gvsig.remoteClientOld.descriptor.Capabilities;

import org.gvsig.remoteClientOld.exception.UnsupportedVersionException;

/**

 * Factor?a abstracta de drivers WMS

 *

 * @author Fernando Gonz?lez Cort?s

 */

public class WMSAdapterFactory {

    private static ArrayList versions = new ArrayList();

    static {

        /*

         * Se meten en el array versions las distintas versiones

         * del protocolo en orden descendente

         */

        versions.add(WMSAdapter1_1_1.class);

        //versions.add(WMSDriver1_1_0.class);

     }

    /**

     * M?todo que dada una respuesta de getCapabilities y un iterador sobre una

     * coleccion de WMSClient's ordenada descendentemente devuelve el cliente

     * cuya version es igual o inmediatamente inferior

     *

     * @param caps Capabilities con la respuesta del servidor

     * @param clients Iterador de conjunto ordenado descendientemente

     *

     * @return cliente cuya version es igual o inmediatamente inferior

     * @throws IllegalAccessException

     * @throws InstantiationException

     * 

     */

    private static WMSAdapter getDriver(Capabilities caps, Iterator clients) throws InstantiationException, IllegalAccessException {

        while (clients.hasNext()) {

            WMSAdapter client = (WMSAdapter) ((Class)clients.next()).newInstance();

            int ret = caps.getServiceInformation().getVersion().compareTo(client.getVersion());

            if (ret >= 0) {

                return client;

            }

        }

        return null;

    }

    /**

     * Establece la versi?n con la que se comunicar? con el servidor y devuelve

     * el objeto Capabilities obtenido con dicha versi?n

     *

     * @param host maquina con la que se negocia

     *

     * @return instancia de un cliente capaz de negociar con el host que se

     *         pasa como par?metro

     *

     * @throws UnsupportedVersionException Si no se encuentra un cliente

     *         apropiado para el host dado

     * @throws IOException Si se produce un error de entrada salida en la

     *         comunicaci?n con el servidor

     * @throws IllegalAccessException

     * @throws InstantiationException

     */

     private static WMSAdapter negotiate(URL host)

     throws UnsupportedVersionException, IOException, InstantiationException, IllegalAccessException 

     {

        if (versions.size() == 0) 

        {

            throw new UnsupportedVersionException("No registered clients");

        }

        Iterator iVersion = versions.iterator();

        if (iVersion.hasNext()) { 

            do {                

                Capabilities aux = null;

                WMSAdapter iV;

                do {

                    if (!iVersion.hasNext()) {

                        throw new UnsupportedVersionException(

                            "Cannot understand server version");

                    }

                    iV = (WMSAdapter)((Class)iVersion.next()).newInstance();

                    aux = iV.getCapabilities(); //Se pide version al servidor

                } while (aux.getServiceInformation().getVersion() == null); //Se itera hasta que se lee una versi?n

                int res = aux.getServiceInformation().getVersion().compareTo(iV.getVersion());

                if (res == 0) { //Si es la misma que nuestra version                

                    return createVersionDriver(iV.getVersion());

                } else if (res > 0) { //Si es mayor que nuestra version

                    throw new UnsupportedVersionException(

                        "Server Version too high: " + aux.getServiceInformation().getVersion());

                } else { //Si es menor que nuestra version

                         //Obtenemos la primera version menor o igual que tengamos

                    WMSAdapter lower = getDriver(aux, iVersion);

                    if (lower == null) { //Si no hay ninguna

                        throw new UnsupportedVersionException(

                            "Lowest server version is " + aux.getServiceInformation().getVersion());

                    } else {

                        if (lower.getVersion().equals(aux.getServiceInformation().getVersion())) { 

                            return createVersionDriver(lower.getVersion());

                        } else { //Si hay una version menor que la que retorno el servidor

                            iV = lower;

                        }

                    }

                }

            } while (iVersion.hasNext());

        }

        throw new UnsupportedVersionException("Negotiation failed");

    }

     /**

      * It creates an instance of a WMSDriver class.

      *

      * @param String, with the version of the driver to be created

      * @return WMSDriver.

      */

       private static WMSAdapter createVersionDriver(String version)             

       throws UnsupportedVersionException

       {

         try

         {

           Class driver;

           version.replace('.', '_');

           driver = Class.forName("org.gvsig.remoteClient.driver.wms.wms1_1_1.WMSDriver" + version);

           return (WMSAdapter)driver.newInstance();

         }

         catch (Exception e)

         {

           throw new UnsupportedVersionException("WMSDriverFactory. Unknown driver version " + e);           

         }

       }     

    /**

     * Establece la versi?n con la que se comunicar? con el servidor y devuelve

     * el objeto Capabilities obtenido con dicha versi?n

     *

     * @param host maquina con la que se negocia

     *

     * @return instancia de un cliente capaz de negociar con el host que se

     *         pasa como par?metro

     *

     * @throws UnsupportedVersionException Si no se encuentra un cliente

     *         apropiado para el host dado

     * @throws IOException Si se produce un error de entrada salida en la

     *         comunicaci?n con el servidor

     */

    public static WMSClient getClient(URL host)

        throws UnsupportedVersionException, IOException

        {

        try {

                        return new WMSClient(negotiate(host));

                } catch (InstantiationException e) {

                        throw new RuntimeException(e);

                } catch (IllegalAccessException e) {

                        throw new RuntimeException(e);

                }

    }

    /**

     * @deprecated

     * */    

    public static WMSAdapter getDriver(URL host)

    throws UnsupportedVersionException, IOException

    {

    try {

                return negotiate(host);

        } catch (InstantiationException e) {

                throw new RuntimeException(e);

        } catch (IllegalAccessException e) {

                throw new RuntimeException(e);

        }

}    

}