Application: gvSIG desktop

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2013 gvSIG Association.

 *

 * 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 3

 * 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., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.remoteclient.wfs;

import java.io.File;

import java.net.URL;

import java.util.ArrayList;

import java.util.Hashtable;

import java.util.StringTokenizer;

import org.gvsig.compat.net.ICancellable;

import org.gvsig.remoteclient.ogc.OGCProtocolHandler;

import org.gvsig.remoteclient.ogc.OGCServiceInformation;

import org.gvsig.remoteclient.utils.CapabilitiesTags;

import org.gvsig.remoteclient.wfs.exceptions.WFSException;

import org.gvsig.remoteclient.wfs.request.WFSDescribeFeatureTypeRequest;

import org.gvsig.remoteclient.wfs.request.WFSGetFeatureRequest;

import org.gvsig.remoteclient.wfs.request.WFSTLockFeatureRequest;

import org.gvsig.remoteclient.wfs.request.WFSTransactionRequest;

import org.gvsig.remoteclient.wfs.schema.GMLTags;

import org.kxml2.io.KXmlParser;

/**

 * @author Jorge Piera Llodr? (piera_jor@gva.es)

 */

public abstract class WFSProtocolHandler extends OGCProtocolHandler {

        //protected static Logger LOG = LoggerFactory.getLogger(WFSProtocolHandler.class);

    /**

         * WFS metadata

         */

        protected WFSServiceInformation serviceInfo = new WFSServiceInformation();

        protected Hashtable features = new Hashtable();

        protected String currentFeature = null;

        private int numberOfErrors = 0;

        /**

         * This class contains all the data that the library is able

         * to retrieve of the server for all the requests. 

         */

        protected ArrayList wfsRequestInformations = new ArrayList();

        /**

         * Clear the connection

         */

        private void clear() {

                features.clear();

                serviceInfo.clear();

        }

        /**

         * <p>Builds a GetCapabilities request that is sent to the WFS

         * the response will be parse to extract the data needed by the

         * WFS client</p>

         */

        public void getCapabilities(WFSStatus status,boolean override, ICancellable cancel) throws WFSException {

                URL request = null;

                try {

                        request = new URL(buildCapabilitiesRequest(status));

                        if (override){

                            downloader.removeURL(request);

                        }

                        File f = downloader.downloadFile(request,"wfs_capabilities.xml", cancel);

                        if (f == null)

                                return;

                        clear();

                        parseCapabilities(f);

                } catch (Exception e){

                        throw new WFSException(e);

                }

        }    

        /**

         * @return

         */

        private String buildCapabilitiesRequest(WFSStatus status) {

                StringBuffer req = new StringBuffer();

                String symbol = null;

                String onlineResource;

                if (status == null || status.getOnlineResource() == null)

                        onlineResource = getHost();

                else 

                        onlineResource = status.getOnlineResource();

                symbol = getSymbol(onlineResource);

                req.append(onlineResource).append(symbol).append("REQUEST=GetCapabilities&SERVICE=WFS&");

                req.append("VERSION=").append(getVersion()).append("&EXCEPTIONS=XML");

                return req.toString();

        }   

        /**

         * Builds the GetCapabilitiesRequest according to the OGC WFS Specifications

         * without a VERSION, to get the highest version than a WFS supports.

         */

        public static String buildCapabilitiesSuitableVersionRequest(String _host, String _version)

        {

                int index = _host.indexOf('?');

                if (index > -1) {

                        String host = _host.substring(0, index + 1);

                        String query = _host.substring(index + 1, _host.length());

                        StringTokenizer tokens = new StringTokenizer(query, "&");

                        String newQuery = "", token;

                        // If there is a field or a value with spaces, (and then it's on different tokens) -> unify them

                        while (tokens.hasMoreTokens()) {

                                token = tokens.nextToken().trim();

                                if (token.toUpperCase().compareTo("REQUEST=GETCAPABILITIES") == 0)

                                        continue;

                                if (token.toUpperCase().compareTo("SERVICE=WFS") == 0)

                                        continue;

                                if ((_version != null) && (_version.length() > 0)) {

                                        if (token.toUpperCase().compareTo("VERSION=" + _version) == 0)

                                                continue;

                                }

                                if (token.toUpperCase().compareTo("EXCEPTIONS=XML") == 0)

                                        continue;

                                newQuery += token + "&";

                        }

                        _host = host + newQuery;

                }

                else {

                        _host += "?";

                }

                if ((_version != null) && (_version.compareTo("") != 0))

                        _host += "REQUEST=GetCapabilities&SERVICE=WFS&VERSION=" + _version + "&EXCEPTIONS=XML";

                else

                        _host += "REQUEST=GetCapabilities&SERVICE=WFS&EXCEPTIONS=XML";

                return _host;    

        }

        /**

         * <p>Builds a describeFeatureType request that is sent to the WFS

         * the response will be parse to extract the data needed by the

         * WFS client</p>

         * @param status

         * WFS client status. Contains all the information to create

         * the query. In this case, the only the feature name is needed.

         */

        public File describeFeatureType(WFSStatus status,boolean override, ICancellable cancel)throws WFSException {

                this.currentFeature = status.getFeatureFullName();

                //sets the namespace URI         

                if ((status.getNamespacePrefix() != null) && (status.getNamespaceLocation() == null)){                        

                        String namespaceURI = serviceInfo.getNamespace(status.getNamespacePrefix());

                        if (namespaceURI != null){

                                status.setNamespaceLocation(namespaceURI);                                

                        }

                }

                try {

                        WFSDescribeFeatureTypeRequest request = createDescribeFeatureTypeRequest(status);

                        File f = request.sendRequest(cancel);

                        return f;

                } catch (Exception e){

                        throw new WFSException(e);

                }

        }             

        /**

         * <p>Builds a getFeature request that is sent to the WFS

         * the response will be parse to extract the data needed by the

         * WFS client</p>

         * @param status

         * WFS client status. Contains all the information to create

         * the query. 

         * @return File

         * GML file

         */    

        public File getFeature(WFSStatus status,boolean override, ICancellable cancel) throws WFSException{

                try{                

                        WFSGetFeatureRequest request = createGetFeatureRequest(status);

                        File f = request.sendRequest(cancel);                        

                        parseGetFeature(f, status.getNamespacePrefix());

                        return f;

                } catch (Exception e){

                        throw new WFSException(e);

                }                

        }

        /**

         * parses the data retrieved by the GetFeature XML document. It is

         * used just to find errors

         */

        protected abstract boolean parseGetFeature(File f,String nameSpace) throws WFSException;

        /**

         * <p>Builds a transaction request that is sent to the WFS

         * the response will be parse to extract the data needed by the

         * WFS client</p>

         * @param status

         * WFS client status. Contains all the information to create

         * the query. 

         */   

        public void transaction(WFSStatus status,boolean override, ICancellable cancel) throws WFSException {

                try {

                    WFSTransactionRequest request = createTransactionRequest(status);

            File f = request.sendRequest(cancel);           

            parseTransaction(f, status); 

                } catch (Exception e){

                        throw new WFSException(e);

                }

        }

        /**

         * <p>Builds a transaction request that is sent to the WFS

         * the response will be parse to extract the data needed by the

         * WFS client</p>

         * @param status

         * WFS client status. Contains all the information to create

         * the query. 

         */

        private String buildTransactionRequest(WFSStatus status){

                StringBuffer req = new StringBuffer();

                String symbol = null;

                String onlineResource;

                if(serviceInfo.getOnlineResource(CapabilitiesTags.WFS_TRANSACTION) != null){

                        onlineResource = serviceInfo.getOnlineResource(CapabilitiesTags.WFS_TRANSACTION);

                }else {

                        onlineResource = getHost();

                }

                symbol = getSymbol(onlineResource);

                req.append(onlineResource);

                return req.toString();

        }

        /**

         * parses the data retrieved by the transaction operation

         * @param f

         * The retrieved file

         * @param nameSpace

         * The namespace

         */

        protected abstract boolean parseTransaction(File f,  WFSStatus status) throws WFSException;

        /**

         * <p>Builds a lockFeature request that is sent to the WFS

         * the response will be parse to extract the data needed by the

         * WFS client</p>

         * @param status

         * WFS client status. Contains all the information to create

         * the query. 

         */  

        public void lockFeature(WFSStatus status,boolean override, ICancellable cancel) throws WFSException {

                try {

                        WFSTLockFeatureRequest request = createLockFeatureRequest(status);

                        File f = request.sendRequest(cancel);

                        parseLockFeature(f,status.getNamespacePrefix(),status);

                } catch(WFSException e) {

                        throw e;

                } catch (Exception e){

                        throw new WFSException(e);

                }                

        }        

        /**

         * parses the data retrieved by the LockFeature operation

         */

        protected abstract boolean parseLockFeature(File f,String nameSpace, WFSStatus status) throws WFSException;

        /**

         * @return Returns the features.

         */

        public Hashtable getFeatures() {

                return features;

        }

        /**

         * @return Returns the currentFeature.

         */

        public String getCurrentFeature() {

                return currentFeature;

        }

        /**

         * @param currentFeature The currentFeature to set.

         */

        public void setCurrentFeature(String currentFeature) {

                this.currentFeature = currentFeature;

        }    

        /**

         * It parses the attributes of the current KXMLParser 

         * and add the new namespaces to the service information

         * @param parser

         * The KXML parser

         */

        protected void parseNamespaces(KXmlParser parser){

                for (int i=0 ; i<parser.getAttributeCount() ; i++){

                        String attName = parser.getAttributeName(i);

                        if (attName.startsWith(GMLTags.XML_NAMESPACE)){

                                int index = attName.indexOf(":");

                                if (index > 0){

                                        serviceInfo.addNamespace(attName.substring(index+1, attName.length()), 

                                                        parser.getAttributeValue(i));

                                }

                        }

                }                        

        }

        /* (non-Javadoc)

         * @see org.gvsig.remoteClient.ogc.OGCProtocolHandler#getServiceInformation()

         */

        public OGCServiceInformation getServiceInformation() {

                return serviceInfo;

        }        

        /**

         * @param status

         * The WFS status

         * @param protocolHandler

         * The handler to parse the requests

         * @return an object to send the DescribeFeatureType requests

         */

        protected abstract WFSDescribeFeatureTypeRequest createDescribeFeatureTypeRequest(WFSStatus status);

        /**

         * @param status

         * The WFS status

         * @param protocolHandler

         * The handler to parse the requests

         * @return an object to send the GetFeature requests

         */

        protected abstract WFSGetFeatureRequest createGetFeatureRequest(WFSStatus status);

        /**

         * @param status

         * The WFS status

         * @param protocolHandler

         * The handler to parse the requests

         * @return an object to send the LockFeature requests

         */

        protected abstract WFSTLockFeatureRequest createLockFeatureRequest(WFSStatus status);

        /**

     * @param status

     * The WFS status

     * @param protocolHandler

     * The handler to parse the requests

     * @return an object to send the Transaction request

     */        

        protected abstract WFSTransactionRequest createTransactionRequest(WFSStatus status);

        /**

         * @return the wfsRequestInformations

         */

        ArrayList getWfsRequestInformations() {

                return wfsRequestInformations;

        }

        /**

         * Adds a new WFSRequestInformation

         * @param wfsRequestInformation

         */

        public void addLastWfsRequestInformation(

                        WFSRequestInformation wfsRequestInformation) {

                wfsRequestInformations.add(wfsRequestInformation);                

        }

        /**

         * @return the lastWfsRequestInformation

         */

        public WFSRequestInformation getLastWfsRequestInformation() {

                if (wfsRequestInformations.size() > 0){

                        return (WFSRequestInformation)wfsRequestInformations.get(wfsRequestInformations.size() - 1);

                }

                return null;

        }

}