| gvSIG desktop 1

/* gvSIG. Geographic Information System of the Valencian Government

*

* Copyright (C) 2007-2008 Infrastructures and Transports Department

* of the Valencian Government (CIT)

*

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

* MA  02110-1301, USA.

*

*/

package org.gvsig.remoteclient.wmts;

import java.io.ByteArrayInputStream;

import java.io.File;

import java.io.IOException;

import java.util.ArrayList;

import java.util.StringTokenizer;

import org.gvsig.compat.net.ICancellable;

import org.gvsig.remoteclient.exceptions.ServerErrorException;

import org.gvsig.remoteclient.ogc.OGCProtocolHandler;

import org.gvsig.remoteclient.ogc.OGCServiceInformation;

import org.gvsig.remoteclient.utils.ExceptionTags;

import org.gvsig.remoteclient.utils.Utilities;

import org.gvsig.remoteclient.wms.WMSServiceInformation;

import org.gvsig.remoteclient.wmts.exception.WMTSException;

import org.gvsig.remoteclient.wmts.request.WMTSGetCapabilitiesRequest;

import org.gvsig.remoteclient.wmts.request.WMTSGetTileRequest;

import org.kxml2.io.KXmlParser;

import org.xmlpull.v1.XmlPullParserException;

/**

 * <p> Abstract class that represents handlers to comunicate via WMS protocol.</p>

 * 

 * @author Nacho Brodin (nachobrodin@gmail.com)

 */

public abstract class WMTSProtocolHandler extends OGCProtocolHandler {

        /**

         * Encoding used to parse different xml documents.

         */

        protected String                 encoding    = "UTF-8";

    protected WMSServiceInformation  serviceInfo = null;

    protected abstract WMTSGetTileRequest createGetTileRequest(WMTSStatus status);

    protected abstract WMTSGetCapabilitiesRequest createGetCapabilitiesRequest();

    /**

     * Sets the status object

     * @param status

     */

    protected abstract void setStatus(WMTSServerDescription status);

    public File getTile(WMTSStatus status, ICancellable cancel) throws ServerErrorException, WMTSException {

            try {

                        WMTSGetTileRequest request = createGetTileRequest(status);

                        File f = request.sendRequest(cancel);

                        if (f== null)

                            return null;

            if (Utilities.isTextFile(f)) {

                byte[] data = fileToBytes(f);

                            WMTSException wmsEx = null;

                    String exceptionMessage = parseException(data);

                if (exceptionMessage == null) {

                         String error = new String(data);

                        int pos = error.indexOf("<?xml");

                        if (pos!= -1) {

                                String xml = error.substring(pos,error.length());

                                exceptionMessage = parseException(xml.getBytes());

                        }

                    if (exceptionMessage == null)

                            exceptionMessage = new String(data);

                }

                     wmsEx = new WMTSException(exceptionMessage);

                    // Since it is an error file, It must be deleted from the cache

                    downloader.removeURL(request);

                throw wmsEx;

            }

                        return f;

                }

                catch(IOException e) {

                        e.printStackTrace();

            throw new ServerErrorException();

                }

    }

    /**

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

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

         * WMS client</p>

         * @param override, if true the previous downloaded data will be overridden

         */

    public void getCapabilities(WMTSServerDescription status, boolean override, ICancellable cancel) {

            try {

                    setStatus(status);

                        WMTSGetCapabilitiesRequest request = createGetCapabilitiesRequest();

                        File f = request.sendRequest(cancel);                        

                        if (f == null)

                                return;

                        parseCapabilities(f);

            } catch(Exception e) {

                        e.printStackTrace();

                }

    }

    /**

     * Builds the GetCapabilitiesRequest according to the OGC WMS Specifications

     * without a VERSION, to get the highest version than a WMS 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=WMTS") == 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=WMTS&VERSION=" + _version;

            else

                    _host += "REQUEST=GetCapabilities&SERVICE=WMTS";

            return _host;

    }

   /*

    * (non-Javadoc)

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

    */

    public OGCServiceInformation getServiceInformation() {

        return serviceInfo;

    }

    @SuppressWarnings("unchecked")

        protected String parseException(byte[] data) {

        ArrayList errors = new ArrayList();

        KXmlParser kxmlParser = new KXmlParser();

        try

        {

            kxmlParser.setInput(new ByteArrayInputStream(data), encoding);

            kxmlParser.nextTag();

            int tag;

            if ( kxmlParser.getEventType() != KXmlParser.END_DOCUMENT )

            {

                kxmlParser.require(KXmlParser.START_TAG, null, ExceptionTags.EXCEPTION_ROOT);

                tag = kxmlParser.nextTag();

                 while(tag != KXmlParser.END_DOCUMENT)

                 {

                     switch(tag)

                     {

                        case KXmlParser.START_TAG:

                            if (kxmlParser.getName().compareTo(ExceptionTags.SERVICE_EXCEPTION)==0){

                                String errorCode = kxmlParser.getAttributeValue("", ExceptionTags.CODE);

                                errorCode = (errorCode != null) ? "["+errorCode+"] " : "";

                                String errorMessage = kxmlParser.nextText();

                                errors.add(errorCode+errorMessage);

                            }

                            break;

                        case KXmlParser.END_TAG:

                            break;

                     }

                     tag = kxmlParser.nextTag();

                 }

                 //kxmlParser.require(KXmlParser.END_DOCUMENT, null, null);

            }

        }

        catch(XmlPullParserException parser_ex){

            parser_ex.printStackTrace();

        }

        catch (IOException ioe) {

            ioe.printStackTrace();

        }

        String message = errors.size()>0? "" : null;

        for (int i = 0; i < errors.size(); i++) {

            message += (String) errors.get(i)+"\n";

        }

        return message;

    }

 }