ingo@219: package de.intevation.flys.client.server;
ingo@219: 
ingo@219: import java.util.ArrayList;
ingo@219: import java.util.List;
ingo@219: 
ingo@219: import javax.xml.xpath.XPathConstants;
ingo@219: 
ingo@219: import org.w3c.dom.Document;
ingo@219: import org.w3c.dom.Element;
ingo@219: import org.w3c.dom.Node;
ingo@219: import org.w3c.dom.NodeList;
ingo@219: 
ingo@219: import com.google.gwt.user.server.rpc.RemoteServiceServlet;
ingo@219: 
ingo@219: import de.intevation.artifacts.common.ArtifactNamespaceContext;
ingo@219: import de.intevation.artifacts.common.utils.XMLUtils;
ingo@219: 
ingo@219: import de.intevation.artifacts.httpclient.exceptions.ConnectionException;
ingo@219: import de.intevation.artifacts.httpclient.http.HttpClient;
ingo@219: import de.intevation.artifacts.httpclient.http.HttpClientImpl;
ingo@219: 
ingo@219: import de.intevation.flys.client.shared.exceptions.ServerException;
ingo@219: import de.intevation.flys.client.client.services.DistanceInfoService;
ingo@219: import de.intevation.flys.client.shared.model.DistanceInfoObject;
ingo@219: import de.intevation.flys.client.shared.model.DistanceInfoObjectImpl;
ingo@219: 
ingo@219: 
ingo@219: /**
ingo@219:  * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
ingo@219:  */
ingo@219: public class DistanceInfoServiceImpl
ingo@219: extends      RemoteServiceServlet
ingo@219: implements   DistanceInfoService
ingo@219: {
ingo@219:     public static final String ERROR_NO_DISTANCEINFO_FOUND =
ingo@219:         "error_no_distanceinfo_found";
ingo@219: 
ingo@219:     public static final String XPATH_DISTANCES = "art:distances/art:distance";
ingo@219: 
ingo@219: 
ingo@229:     public DistanceInfoObject[] getDistanceInfo(
ingo@229:         String url,
ingo@229:         String locale,
ingo@229:         String river)
ingo@219:     throws ServerException
ingo@219:     {
ingo@219:         System.out.println("DistanceInfoServiceImpl.getDistanceInfo");
ingo@219: 
ingo@219:         Document doc = XMLUtils.newDocument();
ingo@219: 
ingo@219:         XMLUtils.ElementCreator ec = new XMLUtils.ElementCreator(
ingo@219:             doc,
ingo@219:             ArtifactNamespaceContext.NAMESPACE_URI,
ingo@219:             ArtifactNamespaceContext.NAMESPACE_PREFIX);
ingo@219: 
ingo@219:         Element riverEl = ec.create("river");
ingo@219: 
ingo@219:         riverEl.setTextContent(river);
ingo@219: 
ingo@219:         doc.appendChild(riverEl);
ingo@219: 
ingo@229:         HttpClient client = new HttpClientImpl(url, locale);
ingo@219: 
ingo@219:         try {
ingo@219:             Document result = client.callService(url, "distanceinfo", doc);
ingo@219: 
ingo@219:             System.out.println("Extract distance info objects now.");
ingo@219:             DistanceInfoObject[] objects = extractDistanceInfoObjects(result);
ingo@219: 
ingo@219:             if (objects != null && objects.length > 0) {
ingo@219:                 return objects;
ingo@219:             }
ingo@219:         }
ingo@219:         catch (ConnectionException ce) {
ingo@219:             System.err.println(ce.getLocalizedMessage());
ingo@219:         }
ingo@219: 
ingo@219:         throw new ServerException(ERROR_NO_DISTANCEINFO_FOUND);
ingo@219:     }
ingo@219: 
ingo@219: 
ingo@219:     /**
ingo@219:      * Extracts all distance info objects from <i>result</i> document.
ingo@219:      *
ingo@219:      * @param result The document retrieved by the server.
ingo@219:      *
ingo@219:      * @return a list of DistanceInfoObjects.
ingo@219:      */
ingo@219:     protected DistanceInfoObject[] extractDistanceInfoObjects(Document result)
ingo@219:     throws    ServerException
ingo@219:     {
ingo@219:         NodeList list = (NodeList) XMLUtils.xpath(
ingo@219:             result,
ingo@219:             XPATH_DISTANCES,
ingo@219:             XPathConstants.NODESET,
ingo@219:             ArtifactNamespaceContext.INSTANCE);
ingo@219: 
ingo@219:         if (list == null || list.getLength() == 0) {
ingo@219:             System.err.println("No distance info found.");
ingo@219: 
ingo@219:             throw new ServerException(ERROR_NO_DISTANCEINFO_FOUND);
ingo@219:         }
ingo@219: 
ingo@219:         int num = list.getLength();
ingo@219:         System.out.println("Response contains " + num + " objects.");
ingo@219: 
ingo@219:         List<DistanceInfoObject> objects =
ingo@219:             new ArrayList<DistanceInfoObject>(num);
ingo@219: 
ingo@219:         for (int i = 0; i < num; i++) {
ingo@219:             DistanceInfoObject obj = buildDistanceInfoObject(list.item(i));
ingo@219: 
ingo@219:             if (obj != null) {
ingo@219:                 objects.add(obj);
ingo@219:             }
ingo@219:         }
ingo@219: 
ingo@219:         System.out.println("Retrieved " + objects.size() + " distances.");
ingo@219: 
ingo@219:         return (DistanceInfoObject[])
ingo@219:             objects.toArray(new DistanceInfoObject[num]);
ingo@219:     }
ingo@219: 
ingo@219: 
ingo@219:     /**
ingo@219:      * Extracts information for a single distance info object and intializes an
ingo@219:      * DistanceInfoObject with them.
ingo@219:      *
ingo@219:      * @param node The node that contains the information.
ingo@219:      *
ingo@219:      * @return a valid DistanceInfoObject.
ingo@219:      */
ingo@219:     protected DistanceInfoObject buildDistanceInfoObject(Node node) {
ingo@219:         String desc = XMLUtils.xpathString(
ingo@219:             node, "@art:description", ArtifactNamespaceContext.INSTANCE);
ingo@219: 
ingo@219:         String from = XMLUtils.xpathString(
ingo@219:             node, "@art:from", ArtifactNamespaceContext.INSTANCE);
ingo@219: 
ingo@219:         String to = XMLUtils.xpathString(
ingo@219:             node, "@art:to", ArtifactNamespaceContext.INSTANCE);
ingo@219: 
ingo@219:         String riverside = XMLUtils.xpathString(
ingo@219:             node, "@art:riverside", ArtifactNamespaceContext.INSTANCE);
ingo@219: 
ingo@219:         if (desc != null && from != null) {
ingo@219:             try {
ingo@219:                 return new DistanceInfoObjectImpl(
ingo@219:                     desc,
ingo@219:                     new Double(from),
ingo@219:                     to != null && to.trim().length() > 0 ? new Double(to) : null,
ingo@219:                     riverside);
ingo@219:             }
ingo@219:             catch (NumberFormatException nfe) {
ingo@219:                 System.err.println(nfe.getLocalizedMessage());
ingo@219:             }
ingo@219:         }
ingo@219: 
ingo@219:         System.err.println("Invalid distance info object found.");
ingo@219: 
ingo@219:         return null;
ingo@219:     }
ingo@219: }
ingo@219: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :