--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-client/src/main/java/de/intevation/flys/client/server/DistanceInfoServiceImpl.java	Mon Apr 11 14:32:36 2011 +0000
@@ -0,0 +1,161 @@
+package de.intevation.flys.client.server;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.xml.xpath.XPathConstants;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+
+import com.google.gwt.user.server.rpc.RemoteServiceServlet;
+
+import de.intevation.artifacts.common.ArtifactNamespaceContext;
+import de.intevation.artifacts.common.utils.XMLUtils;
+
+import de.intevation.artifacts.httpclient.exceptions.ConnectionException;
+import de.intevation.artifacts.httpclient.http.HttpClient;
+import de.intevation.artifacts.httpclient.http.HttpClientImpl;
+
+import de.intevation.flys.client.shared.exceptions.ServerException;
+import de.intevation.flys.client.client.services.DistanceInfoService;
+import de.intevation.flys.client.shared.model.DistanceInfoObject;
+import de.intevation.flys.client.shared.model.DistanceInfoObjectImpl;
+
+
+/**
+ * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
+ */
+public class DistanceInfoServiceImpl
+extends      RemoteServiceServlet
+implements   DistanceInfoService
+{
+    public static final String ERROR_NO_DISTANCEINFO_FOUND =
+        "error_no_distanceinfo_found";
+
+    public static final String XPATH_DISTANCES = "art:distances/art:distance";
+
+
+    public DistanceInfoObject[] getDistanceInfo(String url, String river)
+    throws ServerException
+    {
+        System.out.println("DistanceInfoServiceImpl.getDistanceInfo");
+
+        Document doc = XMLUtils.newDocument();
+
+        XMLUtils.ElementCreator ec = new XMLUtils.ElementCreator(
+            doc,
+            ArtifactNamespaceContext.NAMESPACE_URI,
+            ArtifactNamespaceContext.NAMESPACE_PREFIX);
+
+        Element riverEl = ec.create("river");
+
+        riverEl.setTextContent(river);
+
+        doc.appendChild(riverEl);
+
+        HttpClient client = new HttpClientImpl(url);
+
+        try {
+            Document result = client.callService(url, "distanceinfo", doc);
+
+            System.out.println("Extract distance info objects now.");
+            DistanceInfoObject[] objects = extractDistanceInfoObjects(result);
+
+            if (objects != null && objects.length > 0) {
+                return objects;
+            }
+        }
+        catch (ConnectionException ce) {
+            System.err.println(ce.getLocalizedMessage());
+        }
+
+        throw new ServerException(ERROR_NO_DISTANCEINFO_FOUND);
+    }
+
+
+    /**
+     * Extracts all distance info objects from <i>result</i> document.
+     *
+     * @param result The document retrieved by the server.
+     *
+     * @return a list of DistanceInfoObjects.
+     */
+    protected DistanceInfoObject[] extractDistanceInfoObjects(Document result)
+    throws    ServerException
+    {
+        NodeList list = (NodeList) XMLUtils.xpath(
+            result,
+            XPATH_DISTANCES,
+            XPathConstants.NODESET,
+            ArtifactNamespaceContext.INSTANCE);
+
+        if (list == null || list.getLength() == 0) {
+            System.err.println("No distance info found.");
+
+            throw new ServerException(ERROR_NO_DISTANCEINFO_FOUND);
+        }
+
+        int num = list.getLength();
+        System.out.println("Response contains " + num + " objects.");
+
+        List<DistanceInfoObject> objects =
+            new ArrayList<DistanceInfoObject>(num);
+
+        for (int i = 0; i < num; i++) {
+            DistanceInfoObject obj = buildDistanceInfoObject(list.item(i));
+
+            if (obj != null) {
+                objects.add(obj);
+            }
+        }
+
+        System.out.println("Retrieved " + objects.size() + " distances.");
+
+        return (DistanceInfoObject[])
+            objects.toArray(new DistanceInfoObject[num]);
+    }
+
+
+    /**
+     * Extracts information for a single distance info object and intializes an
+     * DistanceInfoObject with them.
+     *
+     * @param node The node that contains the information.
+     *
+     * @return a valid DistanceInfoObject.
+     */
+    protected DistanceInfoObject buildDistanceInfoObject(Node node) {
+        String desc = XMLUtils.xpathString(
+            node, "@art:description", ArtifactNamespaceContext.INSTANCE);
+
+        String from = XMLUtils.xpathString(
+            node, "@art:from", ArtifactNamespaceContext.INSTANCE);
+
+        String to = XMLUtils.xpathString(
+            node, "@art:to", ArtifactNamespaceContext.INSTANCE);
+
+        String riverside = XMLUtils.xpathString(
+            node, "@art:riverside", ArtifactNamespaceContext.INSTANCE);
+
+        if (desc != null && from != null) {
+            try {
+                return new DistanceInfoObjectImpl(
+                    desc,
+                    new Double(from),
+                    to != null && to.trim().length() > 0 ? new Double(to) : null,
+                    riverside);
+            }
+            catch (NumberFormatException nfe) {
+                System.err.println(nfe.getLocalizedMessage());
+            }
+        }
+
+        System.err.println("Invalid distance info object found.");
+
+        return null;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :