Application: gvSIG desktop » gvSIG tools: Catalog

/* 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.catalog.csw.drivers;

import java.net.MalformedURLException;

import java.net.URI;

import java.net.URL;

import java.util.Collection;

import org.gvsig.catalog.csw.drivers.profiles.CSWAbstractProfile;

import org.gvsig.catalog.csw.messages.CSWAbstractMessages;

import org.gvsig.catalog.csw.messages.CSWMessagesFactory;

import org.gvsig.catalog.csw.parsers.CSWCapabilitiesParser;

import org.gvsig.catalog.csw.parsers.CSWDescribeRecordParser;

import org.gvsig.catalog.drivers.AbstractCatalogServiceDriver;

import org.gvsig.catalog.drivers.DiscoveryServiceCapabilities;

import org.gvsig.catalog.drivers.GetRecordsReply;

import org.gvsig.catalog.exceptions.NotSupportedVersionException;

import org.gvsig.catalog.metadataxml.XMLNode;

import org.gvsig.catalog.protocols.HTTPGetProtocol;

import org.gvsig.catalog.protocols.HTTPPostProtocol;

import org.gvsig.catalog.querys.CatalogQuery;

import java.util.Hashtable;

/**

 * This class implements the CSW protocol.

 * 

 * 

 * @author Jorge Piera Llodra (piera_jor@gva.es)

 * @see http://portal.opengeospatial.org/files/?artifact_id=5929&version=1

 */

public abstract class CSWCatalogServiceDriver extends AbstractCatalogServiceDriver {

        protected CSWCapabilities capabilities = null;

        protected CSWAbstractProfile profile = null;

        private static Hashtable servers = new Hashtable();

        /**

         * @return 

         * @param url 

         * @throws NotSupportedVersionException 

         */

        public DiscoveryServiceCapabilities getCapabilities(URI uri) throws NotSupportedVersionException {        

                URL url = null;

                try {

                        url = uri.toURL();

                } catch (MalformedURLException e) {

                        setServerAnswerReady("errorServerNotFound");

                        return null;

                }        

                Collection nodes = new java.util.ArrayList();

                nodes = new HTTPGetProtocol().doQuery(url, CSWAbstractMessages.getHTTPGETCapabilities(), 0);

                CSWCapabilitiesParser parser = new CSWCapabilitiesParser(url, this);

                capabilities = parser.parse((XMLNode)nodes.toArray()[0]);

                //There are servers that need the getCapabilities operation (instead of GetCapabilities)

                if (!(capabilities.isAvailable()) && (capabilities.getException() != null)){

                        CSWException exception = capabilities.getException();

                        if ((exception.getCode().equals(CSWException.CODE_ERROR)) &&

                                        (exception.getSubcode().equals(CSWException.SUBCODE_ERROR))){

                                nodes = new HTTPGetProtocol().doQuery(url, CSWAbstractMessages.getHTTPGETCapabilitiesLower(), 0);

                                capabilities = parser.parse((XMLNode)nodes.toArray()[0]);

                        }

                }

                //If the version can be retrieved the CSWAbstractMessages object

                //cant be created

                setMessages(uri,url);

                return capabilities;

        }

        /*

         * (non-Javadoc)

         * @see es.gva.cit.catalog.drivers.ICatalogServiceDriver#getRecords(java.net.URI, es.gva.cit.catalog.querys.CatalogQuery, int)

         */

        public GetRecordsReply getRecords(URI uri, CatalogQuery query,

                        int firstRecord) {                        

                URL url = capabilities.getOperations().getGetRecordsURLPost();               

                setQuery(query);

                Collection nodes = new java.util.ArrayList();

                try {

                        System.out.println(getMessages(uri).getHTTPPostGetRecordsMessage(capabilities, getQuery(), getServerData(),  firstRecord));

                        nodes = new HTTPPostProtocol().doQuery(url,

                                        getMessages(uri).getHTTPPostGetRecordsMessage(capabilities, getQuery(), getServerData(), firstRecord),

                                        firstRecord);

                } catch (NotSupportedVersionException e) {

                        //This exception never will be thrown

                }                   

                if (nodes == null) 

                        return null;

                XMLNode root = (XMLNode)nodes.toArray()[0];

                int numberOfRecords = getNumberOfRecords(root);

                if (numberOfRecords == -1) {

                        return null;

                }

                getRecordsReply().setNumRecords(numberOfRecords);

                XMLNode[] results = retrieveResults(root);

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

                        getRecordsReply().addRecord(uri, results[i]);

                }

                return getRecordsReply();

        }

        /**

         * Retrieve and parse the results

         * @param root

         * XML root node

         * @return

         */

        protected abstract XMLNode[] retrieveResults(XMLNode root);

        /**

         * This function returns the number of records that have been retrieved.

         * It Reads a Node value.

         * 

         * 

         * @return The number of records

         * @param node The answer tree

         */

        protected int getNumberOfRecords(XMLNode node) {        

                int numberOfRecords = getNumberOfRecords(node,"csw:SearchResults","numberOfRecordsMatched");

                if (numberOfRecords == -1)

                        numberOfRecords = getNumberOfRecords(node,"SearchResults","numberOfRecordsMatched");

                return numberOfRecords;

        } 

        /*

         * (non-Javadoc)

         * @see es.gva.cit.catalogClient.drivers.ICatalogServiceDriver#getDefaultPort()

         */

        public int getDefaultPort() {

                return 80;

        }

        /*

         * (non-Javadoc)

         * @see es.gva.cit.catalogClient.drivers.ICatalogServiceDriver#getDefaultSchema()

         */

        public String getDefaultSchema() {

                return "http";

        }

        /*

         * (non-Javadoc)

         * @see es.gva.cit.catalogClient.drivers.ICatalogServiceDriver#isProtocolSupported(java.net.URI)

         */

        public boolean isProtocolSupported(URI uri) {

                return true;

        } 

        /**

         * @return the class to generate the messages. It depends

         * of the server version

         * @throws NotSupportedVersionException 

         */

        private CSWAbstractMessages getMessages(URI uri) throws NotSupportedVersionException{

                if (servers.containsKey(uri)){

                        return (CSWAbstractMessages)servers.get(uri);

                }

                CSWAbstractMessages messages = CSWMessagesFactory.getMessages(capabilities.getVersion(),

                                (CSWAbstractProfile)getProfile());

                servers.put(uri, messages);

                return messages;

        }

        /**

         * Create and sets the Messages obejct if it is possible

         * @param uri

         * Server URI

         * @param url

         * Server url

         * @throws NotSupportedVersionException

         */

        private void setMessages(URI uri,URL url)throws NotSupportedVersionException{

                Collection nodes = new java.util.ArrayList();

                nodes = new HTTPGetProtocol().doQuery(url, CSWAbstractMessages.getHTTPGETDescribeRecord(capabilities.getVersion()), 0);

                CSWDescribeRecordParser parser = new CSWDescribeRecordParser(url, this);

                parser.parse((XMLNode)nodes.toArray()[0]);

        }        

}