Application: gvSIG desktop

package org.gvsig.remoteClient.wms;

import java.io.ByteArrayInputStream;

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.Reader;

import java.io.StringReader;

import java.net.URL;

import java.net.URLConnection;

import java.util.ArrayList;

import java.util.TreeMap;

import java.util.Vector;

import org.gvsig.remoteClient.exceptions.ServerErrorException;

import org.gvsig.remoteClient.exceptions.WMSException;

import org.gvsig.remoteClient.utils.CapabilitiesTags;

import org.gvsig.remoteClient.utils.ExceptionTags;

import org.gvsig.remoteClient.utils.Utilities;

import org.kxml2.io.KXmlParser;

import org.xmlpull.v1.XmlPullParserException;

import com.iver.andami.PluginServices;

/**

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

 * </p>

 * 

 */

public abstract class WMSProtocolHandler {

        public static final int GETCAPABILITIES_OPERATION = 0;

        public static final int GETMAP_OPERATION = 1;

        public static final int GETFEATUREINFO_OPERATION = 2;

        public static final int DESCRIBELAYER_OPERATION = 3;

        public static final int GETLEGENDGRAPHIC_OPERATION = 4; // this is only for sld-enabled WMS

        /**

         * procotol handler name

         */

    protected String name;

    /**

     * protocol handler version

     */

    protected String version;

    /**

     * host of the WMS to connect

     */

    protected String host;

    /**

     *  port number of the comunication channel of the WMS to connect

     */

    protected String port;    

    /**

     * WMS metadata

     */

    protected ServiceInformation serviceInfo;

    public TreeMap layers;

    public WMSLayer rootLayer;

    public Vector srs;

    // abstract methods to implement by the handlers that implement

    // the connection to a WMS with certain version.

    //    public abstract String getName();   

    //    public abstract String getVersion();

    /**

     * parses the data retrieved by the WMS in XML format. 

     * It will be mostly the WMS Capabilities, but the implementation

     * will be placed in the handler implementing certain version of the protocol.

     * 

     */

    public abstract void parse(File f) ;

    public String getName() {        

            return name;

    } 

    public String getVersion() {        

            return version;

    }    

    public ServiceInformation getServiceInformation() {        

        return serviceInfo;

    }  

    public String getHost ()

    {

            return host;

    }

    public void setHost(String _host)

    {

            host = _host;

    }

    public String getPort()

    {

            return port;

    }

    public void setPort(String _port)

    {

            port = _port;

    }

    /**

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

     * the response (image) will be redirect to the

     * WMS client</p>

     */

    public byte[] getMap(WMSStatus status) throws ServerErrorException, WMSException

    {        

            URL request = null;

                try

                {

                        //TODO:

                        //pass this buildXXXRequest to the WMSProtocolHandlerXXX: The request can depend on the WMS version.

                        request = new URL(buildMapRequest(status));

                        URLConnection conn = request.openConnection();

                        System.out.println(request.toString());

            String type = conn.getContentType();

                    byte[] imageBytes = null;

                    byte[] buffer = new byte[1024*256];

            InputStream is = conn.getInputStream();

                    int readed = 0;

                    for (int i = is.read(buffer); i>0; i = is.read(buffer)){

                // Creates a new buffer to contain the previous readed bytes and the next bunch of bytes

                            byte[] buffered = new byte[readed+i];

                            for (int j = 0; j < buffered.length; j++) {

                                    if (j<readed){

                        // puts the previously downloaded bytes into the image buffer

                                            buffered[j] = imageBytes[j];

                                    }

                                    else {

                        // appends the recently downloaded bytes to the image buffer.

                                            buffered[j] = buffer[j-readed];

                                    }

                                }

                            imageBytes = (byte[]) buffered.clone();

                            readed += i;

                    }

                    if (type !=null && !type.subSequence(0,5).equals("image")) {

                    String exceptionMessage = parseException(imageBytes);

                if (exceptionMessage!=null)

                    throw new WMSException(exceptionMessage);

                throw new ServerErrorException();

            }

                        if (Utilities.isTextData(imageBytes)){

                String exceptionMessage = parseException(imageBytes);

                if (exceptionMessage!=null)

                    throw new WMSException(exceptionMessage);

                throw new ServerErrorException();

            }

                        return imageBytes;

                }

                catch(IOException e)

                {

                        e.printStackTrace();

            throw new ServerErrorException();

                }

    } 

    /* (non-Javadoc)

     * @see org.gvsig.remoteClient.wms.WMSProtocolHandler#parseException(byte[])

     */

    protected String parseException(byte[] data) {

        ArrayList errors = new ArrayList();

        KXmlParser kxmlParser = new KXmlParser();

        Reader reader = new InputStreamReader(new ByteArrayInputStream(data));

        try

        {

            kxmlParser.setInput(reader);        

            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){

            System.out.println(parser_ex.getMessage());

            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;

    }

    /**

         * <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>

         */

    public void getCapabilities()

    {                

            URL request = null;

                try

                {

                        request = new URL(buildCapabilitiesRequest());

                }

                catch(Exception e)

                {

                        e.printStackTrace();

                }

                try

                {

                File f = com.iver.andami.Utilities.downloadFile(request,"wms_capabilities.xml");

            parse(f);

            } catch(Exception e)

                {

                        //TODO

                        e.printStackTrace();

                }

    }

    /**

     * <p>It will send a GetFeatureInfo request to the WMS

     * Parsing the response and redirecting the info to the WMS client</p>

     */

    public String getFeatureInfo(WMSStatus status, int x, int y, int featureCount)

    {

            URL request = null;

            StringBuffer output = new StringBuffer();

            String outputFormat = new String();

            String ServiceException = "ServiceExceptionReport";

                try

                {

                        //TODO:

                        //pass this buildXXXRequest to the WMSProtocolHandlerXXX: The request can depend on the WMS version.

                        request = new URL(buildGetFeatureInfoRequest(status, x, y));

                        //TODO:

                        //see which output format is being requested.                                         

                }

                catch(Exception e)

                {

                        e.printStackTrace();

                }

            try

            {            

                    StringBuffer sb = new StringBuffer();

                    sb.append("<?xml version=\"1.0\" encoding=\"ISO-8859-1\"?>");

                    System.out.println(request.toString());

                    //File f = new File("featureInfo.xml");

                    //DataOutputStream dos = new DataOutputStream(new FileOutputStream(f));           

                    byte[] buffer = new byte[1024*256];                    

                    InputStream is = request.openStream();                    

                    outputFormat = request.openConnection().getContentType();

                    if ( (outputFormat == null) || (outputFormat.indexOf("xml") != -1))

                    {

                            for (int i = is.read(buffer); i>0; i = is.read(buffer)){

                                    //dos.write(buffer, 0, i);

                                    output.append(buffer);                            

                            }

                            //dos.close();

                            is.close();

                            int tag;

                            KXmlParser kxmlParser = null;

                            kxmlParser = new KXmlParser();            

                            //kxmlParser.setInput(new FileReader(f));

                            kxmlParser.setInput(new StringReader(output.toString()));

                                tag = kxmlParser.nextTag();

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

                            {                    

                                          while(tag != KXmlParser.END_DOCUMENT)

                                         {

                                                 switch(tag)

                                                 {

                                                        case KXmlParser.START_TAG:                

                                                                if (kxmlParser.getName().compareTo(ServiceException)==0)

                                                                        return parseException( output.toString().getBytes());

                                                                else                                                                

                                                                        sb.append("<" + kxmlParser.getName() + ">\n");

                                                                break;

                                                        case KXmlParser.END_TAG:        

                                                                sb.append("</" + kxmlParser.getName() + ">\n");

                                                                break;

                                                        case KXmlParser.TEXT:

                                                                sb.append(kxmlParser.getText());                                                

                                                        break;

                                                 }

                                             tag = kxmlParser.next();

                                     }

                            }        

                            //System.out.println(sb.toString());

                            return sb.toString();

                    }

                    else

                    {

                            sb.append("<INFO>").append(PluginServices.getText(this, "info_format_not_supported")).append("</INFO>");

                            return sb.toString();

                    }

                }

            catch(Exception e)

            {

                    e.printStackTrace();

            return "";

            }

    }

    /**

     * 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)

    {

                String req = new String();                

        String symbol = getSymbol(_host);

        req = req + _host + symbol + "REQUEST=GetCapabilities&SERVICE=WMS&";                

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

        {

                req += ("&VERSION=" + _version);

        }

                req += ("&EXCEPTIONS=XML");

                return req;           

    }

    /**

     * Builds the GetCapabilitiesRequest according to the OGC WMS Specifications

     */

    private String buildCapabilitiesRequest()

    {

                String req = new String();

                String host = getHost();

        String symbol = getSymbol(host);

        req = req + getHost() + symbol + "REQUEST=GetCapabilities&SERVICE=WMS&";

                req = req + "VERSION=" + getVersion();

                req += ("&EXCEPTIONS=XML");

                return req;

    }

    /**

     * Builds the GetFeatureInfoRequest according to the OGC WMS Specifications

     */

    private String buildGetFeatureInfoRequest(WMSStatus status, int x, int y)

    {

                String req = new String();

        String symbol = getSymbol(host);

                req = req + getHost() + symbol + "REQUEST=GetFeatureInfo&SERVICE=WMS&";

                req = req + "QUERY_LAYERS="+Utilities.Vector2CS(status.getLayerNames()); 

                req = req + "&VERSION=" + getVersion() + "&";

                req = req + "INFO_FORMAT=application/vnd.ogc.gml&";

                req = req + getPartialQuery(status);

                req = req + "&x="+x + "&y="+y;

       if (status.getExceptionFormat() != null) {

            req += ("&EXCEPTIONS=" + status.getExceptionFormat());

        } else {

            req += ("&EXCEPTIONS=XML");

        }

                return req;

    }    

    /**

     * Builds the GetMapRequest according to the OGC WMS Specifications

     */

    private String buildMapRequest(WMSStatus status)

    { 

                String req = new String();

                String symbol = getSymbol(host);

                req = req + getHost() + symbol + "REQUEST=GetMap&SERVICE=WMS&";

                req = req + "VERSION=" + getVersion() + "&";

                req = req + getPartialQuery(status);

       if (status.getExceptionFormat() != null) {

            req += ("&EXCEPTIONS=" + status.getExceptionFormat());

        } else {

            req += ("&EXCEPTIONS=XML");

        }

                return req;

    }

    /**

     * Just for not repeat code. Gets the correct separator according to the server URL

     * @param h

     * @return

     */

    private static String getSymbol(String h) {

        String symbol;

        if (h.indexOf("?")==-1) 

            symbol = "?";

        else if (h.indexOf("?")!=h.length()-1)

            symbol = "&";

        else

            symbol = "";

        return symbol;

    }

    /**

     * Gets the part of the OGC request that share GetMap and GetFeatureInfo

     * @return String request

     */

    public String getPartialQuery(WMSStatus status)

    {            

        String req = "LAYERS=" + Utilities.Vector2CS(status.getLayerNames()) + 

                    "&SRS=" + status.getSrs() +

                    "&BBOX=" + status.getExtent().getMinX()+ "," +

                                    status.getExtent().getMinY()+ "," +

                                    status.getExtent().getMaxX()+ "," +

                                    status.getExtent().getMaxY() +

                    "&WIDTH=" + status.getWidth() +

                    "&HEIGHT=" + status.getHeight() + "&FORMAT=" + status.getFormat();

        Vector v = status.getStyles();

        if (v!=null && v.size()>0)

                req += "&STYLES=" + Utilities.Vector2CS(v); 

        v = status.getDimensions();

        if (v!=null && v.size()>0)

            req += "&" + Utilities.Vector2URLParamString(v);

        if (status.getTransparency()) {

            req += "&TRANSPARENT=TRUE";

        }

//

//        if (status.getBGColor() != null) {

//            req += ("&COLOR=" + status.getBGColor());

//        }

//

        return req.replaceAll(" ", "%20");

    }

    public void close() {        

        // your code here

    } 

    /**

     * Inner class that represents the description of the WMS metadata.

     * The first part of the capabilities will return the service information

     * from the WMS, this class will hold this information. 

     * 

     */

    public class ServiceInformation {

        public String online_resource;

        public String version;

        public String name;

        public String scope;

        public String title;

        public String abstr;

        public String keywords;

        public String fees;

        public String operationsInfo;

        public String personname;

        public String organization;

        public String function;

        public String addresstype;

        public String address;

        public String place;

        public String province;

        public String postcode;

        public String country;

        public String phone;

        public String fax;

        public String email;

        public Vector formats;

        public Vector operations; // operations that WMS supports

        public ServiceInformation()

        {

                online_resource = new String();

            version = new String();

            name = new String();

            scope = new String();

            title = new String();

            abstr = new String();

            keywords = new String();

            fees = new String();

            operationsInfo = new String();

            personname = new String();

            organization = new String();

            function = new String();

            addresstype = new String();

            address = new String();

            place = new String();

            province = new String();

            postcode = new String();

            country = new String();

            phone = new String();

            fax = new String();

            email = new String();

            formats = new Vector();               

            operations = new Vector();            

        }

        public boolean isQueryable()

        {

                if (operations.contains( CapabilitiesTags.GETFEATUREINFO ))

                        return true;

                else

                        return false;

        }

     }   

 }