--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/server/DistanceInfoServiceImpl.java	Thu Apr 25 15:23:37 2013 +0200
@@ -0,0 +1,160 @@
+package org.dive4elements.river.client.server;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.NodeList;
+
+import org.apache.log4j.Logger;
+
+import com.google.gwt.user.server.rpc.RemoteServiceServlet;
+
+import org.dive4elements.artifacts.common.ArtifactNamespaceContext;
+import org.dive4elements.artifacts.common.utils.XMLUtils;
+
+import org.dive4elements.artifacts.httpclient.exceptions.ConnectionException;
+import org.dive4elements.artifacts.httpclient.http.HttpClient;
+import org.dive4elements.artifacts.httpclient.http.HttpClientImpl;
+
+import org.dive4elements.river.client.shared.exceptions.ServerException;
+import org.dive4elements.river.client.client.services.DistanceInfoService;
+import org.dive4elements.river.client.shared.model.DistanceInfoObject;
+import org.dive4elements.river.client.shared.model.DistanceInfoObjectImpl;
+
+
+/**
+ * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
+ */
+public class DistanceInfoServiceImpl
+extends      RemoteServiceServlet
+implements   DistanceInfoService
+{
+    private static final Logger logger =
+        Logger.getLogger(DistanceInfoServiceImpl.class);
+
+    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 locale,
+        String river)
+    throws ServerException
+    {
+        logger.info("DistanceInfoServiceImpl.getDistanceInfo");
+
+        String url  = getServletContext().getInitParameter("server-url");
+
+        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, locale);
+
+        try {
+            Document result = client.callService(url, "distanceinfo", doc);
+
+            logger.debug("Extract distance info objects now.");
+            DistanceInfoObject[] objects = extractDistanceInfoObjects(result);
+
+            if (objects != null && objects.length > 0) {
+                return objects;
+            }
+        }
+        catch (ConnectionException ce) {
+            logger.error(ce, ce);
+        }
+
+        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 = result.getElementsByTagName("distance");
+
+        if (list == null || list.getLength() == 0) {
+            logger.warn("No distance info found.");
+            throw new ServerException(ERROR_NO_DISTANCEINFO_FOUND);
+        }
+
+        int num = list.getLength();
+        logger.debug("Response contains " + num + " objects.");
+
+        List<DistanceInfoObject> objects =
+            new ArrayList<DistanceInfoObject>(num);
+
+        for (int i = 0; i < num; i++) {
+            DistanceInfoObject obj = buildDistanceInfoObject(
+                (Element)list.item(i));
+
+            if (obj != null) {
+                objects.add(obj);
+            }
+        }
+
+        logger.debug("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(Element node) {
+
+        String desc      = node.getAttribute("description").trim();
+        String from      = node.getAttribute("from").trim();
+        String to        = node.getAttribute("to").trim();
+        String riverside = node.getAttribute("riverside").trim();
+        String bottom    = node.getAttribute("bottom").trim();
+        String top       = node.getAttribute("top").trim();
+
+        if (desc.length() > 0 && from.length() > 0) {
+            try {
+                Double f  = new Double(from);
+                Double t  = to    .length() > 0 ? new Double(to)     : null;
+                Double b  = bottom.length() > 0 ? new Double(bottom) : null;
+                Double tp = top   .length() > 0 ? new Double(top)    : null;
+
+                return new DistanceInfoObjectImpl(desc, f, t, riverside, b, tp);
+            }
+            catch (NumberFormatException nfe) {
+                logger.warn(nfe.getLocalizedMessage());
+            }
+        }
+
+        logger.warn("Invalid distance info object found.");
+
+        return null;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :