ingo@1022: /*
ingo@1022:  * Copyright (c) 2010 by Intevation GmbH
ingo@1022:  *
ingo@1022:  * This program is free software under the LGPL (>=v2.1)
ingo@1022:  * Read the file LGPL.txt coming with the software for details
ingo@1022:  * or visit http://www.gnu.org/licenses/ if it does not exist.
ingo@1022:  */
ingo@1022: 
tim@402: package de.intevation.gnv.action.mapviewer.parser;
tim@402: 
tim@953: import java.io.InputStream;
tim@953: import java.util.ArrayList;
tim@953: import java.util.Collection;
tim@953: 
tim@953: import org.apache.log4j.Logger;
tim@953: import org.w3c.dom.Document;
tim@953: import org.w3c.dom.Element;
tim@953: import org.w3c.dom.NodeList;
tim@953: 
tim@402: import de.intevation.gnv.artifactdatabase.objects.map.DefaultLayer;
tim@402: import de.intevation.gnv.artifactdatabase.objects.map.DefaultMapService;
tim@402: import de.intevation.gnv.artifactdatabase.objects.map.Layer;
tim@402: import de.intevation.gnv.artifactdatabase.objects.map.MapService;
tim@402: import de.intevation.gnv.util.XMLUtils;
tim@402: 
tim@402: /**
tim@953:  * This class provides an XMl-Parser which try's to create an DOM from
tim@953:  * an given Inputstream. Is this is possible it try to read the required
tim@953:  * informations e.g. Mapservices, Layer, SRID and Geometry from the 
tim@953:  * document.
sascha@684:  * @author <a href="mailto:tim.englich@intevation.de">Tim Englich</a>
tim@402:  */
tim@402: public class XMLExternalCallParser implements ExternalCallParser {
sascha@681: 
tim@402:     /**
tim@402:      * the logger, used to log exceptions and additonaly information
tim@402:      */
tim@402:     private static Logger log = Logger.getLogger(XMLExternalCallParser.class);
sascha@681: 
tim@402:     private static String XPATH_GEOMETRY = "/gnviewer/location/data";
tim@402:     private static String XPATH_SRS = "/gnviewer/location/srs";
tim@402:     private static String XPATH_MAPSERVICES_NODESET = "/gnviewer/mapservices/mapservice";
tim@402:     private static String XPATH_LAYER = "layer";
tim@402:     private static String ATTRIBUTE_ID = "id";
tim@402:     private static String ATTRIBUTE_NAME = "name";
tim@402:     private static String ATTRIBUTE_TYPE = "type";
tim@402:     private static String ATTRIBUTE_URL = "url";
sascha@681: 
tim@953:     /**
tim@953:      * The geometry which was parsed from the document.
tim@953:      */
tim@402:     private String geometry = null;
tim@953:     
tim@953:     /**
tim@953:      * The srid which was parsed from the document.
tim@953:      */
tim@402:     private String srs = null;
sascha@681: 
tim@953:     /**
tim@953:      * The mapservices that were parsed from the document.
tim@953:      */
tim@402:     private Collection<MapService> mapServices = null;
sascha@681: 
tim@953:     /**
tim@953:      * The inputstream where the data should be read from.
tim@953:      */
tim@402:     private InputStream inputStream = null;
tim@402: 
tim@402:     /**
tim@402:      * Constructor
tim@953:      * @param inputStream The stream where the data should be read from
tim@402:      */
tim@402:     public XMLExternalCallParser(InputStream inputStream) {
tim@402:         this.inputStream = inputStream;
tim@402:     }
tim@402: 
tim@402:     public String getGeometry() {
tim@402:         return this.geometry;
tim@402:     }
tim@402: 
tim@402:     public Collection<MapService> getMapServices() {
tim@402:         return this.mapServices;
tim@402:     }
tim@402: 
tim@402:     public void parse() throws ExternalCallParserException {
tim@402:         if (inputStream != null){
tim@402:             XMLUtils xmlUtils = new XMLUtils();
tim@402:             Document document = xmlUtils.readDocument(this.inputStream);
tim@402:             if (document != null){
sascha@681: 
tim@953:                 this.geometry = xmlUtils.getStringXPath(document, 
tim@953:                                                         XPATH_GEOMETRY);
tim@402:                 this.srs = xmlUtils.getStringXPath(document, XPATH_SRS);
sascha@681:                 NodeList mapservicesNodes =
tim@953:                       xmlUtils.getNodeSetXPath(document, 
tim@953:                                                XPATH_MAPSERVICES_NODESET);
tim@402:                 if (mapservicesNodes != null){
tim@402:                     this.mapServices = new ArrayList<MapService>(mapservicesNodes.getLength());
tim@402:                     for (int i = 0; i < mapservicesNodes.getLength(); i++){
tim@402:                         Element mapserviceNode = (Element)mapservicesNodes.item(i);
tim@402:                         String mapserviceID = mapserviceNode.getAttribute(ATTRIBUTE_ID);
tim@402:                         String mapserviceType = mapserviceNode.getAttribute(ATTRIBUTE_TYPE);
tim@402:                         String mapserviceUrl = mapserviceNode.getAttribute(ATTRIBUTE_URL);
tim@402:                         NodeList layerNodes = xmlUtils.getNodeSetXPath(mapserviceNode, XPATH_LAYER);
tim@402:                         Collection<Layer> layer = null;
tim@402:                         if (layerNodes != null && layerNodes.getLength() > 0){
tim@402:                             layer = new  ArrayList<Layer>(layerNodes.getLength());
tim@402:                             layer = this.extractLayer(layer, null, layerNodes);
tim@402:                         }else{
tim@402:                             log.debug("No Layer given for this Mapservice");
tim@402:                         }
sascha@681:                         MapService mapService =
tim@402:                              new DefaultMapService(mapserviceID, layer,
tim@402:                                                    mapserviceType, mapserviceUrl);
tim@402:                         this.mapServices.add(mapService);
tim@402:                     }
sascha@681: 
tim@402:                 }else{
tim@953:                     String errMsg = "XML-Document does not contain any " +
tim@953:                                     "Mapservices which are required.";
tim@402:                     log.error(errMsg);
tim@402:                     throw new ExternalCallParserException(errMsg);
tim@402:                 }
sascha@681: 
tim@402:             }else{
tim@953:                 String errMsg = "XML-Document could not " +
tim@953:                                 "be read from InputStream.";
tim@402:                 log.error(errMsg);
tim@402:                 throw new ExternalCallParserException(errMsg);
tim@402:             }
tim@402:         }else{
tim@402:             String errMsg = "No InputStream given for parsing the Call.";
tim@402:             log.error(errMsg);
tim@402:             throw new ExternalCallParserException(errMsg);
tim@402:         }
tim@402:     }
sascha@681: 
tim@402:     /**
tim@402:      * This Method extracts all Layers and put them into the Collection.
tim@953:      * @param layer the collection where the layer should be add to.
tim@953:      * @param groupId the id of the group of the layers
tim@953:      * @param layerNodes the Nodes which should contain the intormations 
tim@953:      *                   about layers
tim@953:      * @return the layer
tim@402:      */
tim@953:     private Collection<Layer> extractLayer(Collection<Layer> layer, 
tim@953:                                            String groupId, 
tim@953:                                            NodeList layerNodes){
tim@402:         for (int i = 0; i < layerNodes.getLength(); i++){
tim@402:             Element layerNode = (Element)layerNodes.item(i);
tim@402:             String id = layerNode.getAttribute(ATTRIBUTE_ID);
tim@402:             String name = layerNode.getAttribute(ATTRIBUTE_NAME);
tim@953:             NodeList localLayerNodes = XMLUtils.getNodeSetXPath(layerNode, 
tim@953:                                                                 XPATH_LAYER);
sascha@681:             Layer tmpLayer = new DefaultLayer(id, name,
sascha@681:                                               (localLayerNodes != null &&
sascha@681:                                                localLayerNodes.getLength() > 0),
tim@402:                                               groupId);
tim@402:             layer.add(tmpLayer);
tim@402:             if (localLayerNodes != null && localLayerNodes.getLength() > 0){
tim@402:                 layer = this.extractLayer(layer, id, localLayerNodes);
tim@402:             }
tim@402:         }
tim@402:         return layer;
tim@402:     }
tim@402: 
tim@402:     public String getSRS() {
tim@402:         return this.srs;
tim@402:     }
tim@402: 
tim@402: }