--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/server/GaugeInfoServiceImpl.java	Thu Apr 25 15:23:37 2013 +0200
@@ -0,0 +1,155 @@
+package org.dive4elements.river.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.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.GaugeInfoService;
+import org.dive4elements.river.client.shared.model.Gauge;
+import org.dive4elements.river.client.shared.model.GaugeImpl;
+
+
+/**
+ * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
+ */
+public class GaugeInfoServiceImpl
+extends      RemoteServiceServlet
+implements   GaugeInfoService
+{
+    private static final Logger logger =
+        Logger.getLogger(GaugeInfoServiceImpl.class);
+
+
+    public static final String ERROR_NO_GAUGES_FOUND =
+        "error_no_gaugeinfo_found";
+
+    public static final String XPATH_GAUGES = "art:service/art:gauge";
+
+
+    public List<Gauge> getGaugeInfo(String rivername, String refnumber)
+    throws ServerException
+    {
+        logger.info("GaugeInfoServiceImpl.getGaugeInfo");
+
+        String url = getServletContext().getInitParameter("server-url");
+
+        Document doc = XMLUtils.newDocument();
+
+        XMLUtils.ElementCreator ec = new XMLUtils.ElementCreator(
+            doc,
+            ArtifactNamespaceContext.NAMESPACE_URI,
+            ArtifactNamespaceContext.NAMESPACE_PREFIX);
+
+        Element river = ec.create("river");
+        ec.addAttr(river, "name", rivername);
+
+        if (refnumber != null && refnumber.length() > 0) {
+            Element filter = ec.create("filter");
+            Element gauge  = ec.create("gauge");
+            gauge.setTextContent(refnumber);
+
+            filter.appendChild(gauge);
+            river.appendChild(filter);
+        }
+
+        doc.appendChild(river);
+
+        HttpClient client = new HttpClientImpl(url);
+
+        try {
+            Document result = client.callService(url, "gaugeinfo", doc);
+
+            logger.debug("Extract gauge info now.");
+            List<Gauge> gauges = extractGauges(result);
+
+            if (gauges != null && gauges.size() > 0) {
+                return gauges;
+            }
+        }
+        catch (ConnectionException ce) {
+            logger.error(ce, ce);
+        }
+
+        throw new ServerException(ERROR_NO_GAUGES_FOUND);
+    }
+
+
+    /**
+     * Extracts all wq info objects from <i>result</i> document.
+     *
+     * @param result The document retrieved by the server.
+     *
+     * @return a list of WQInfoObjects.
+     */
+    protected List<Gauge> extractGauges(Document result)
+    throws    ServerException
+    {
+        List<Gauge> gauges = new ArrayList<Gauge>();
+
+        NodeList list = (NodeList) XMLUtils.xpath(
+            result,
+            XPATH_GAUGES,
+            XPathConstants.NODESET,
+            ArtifactNamespaceContext.INSTANCE);
+
+        if (list == null || list.getLength() == 0) {
+            logger.warn("No gauges found.");
+
+            throw new ServerException(ERROR_NO_GAUGES_FOUND);
+        }
+
+        int num = list.getLength();
+        logger.debug("Response contains " + num + " objects.");
+
+        for (int i = 0; i < num; i++) {
+            Gauge obj = buildGauge((Element) list.item(i));
+
+            if (obj != null) {
+                gauges.add(obj);
+            }
+        }
+
+        logger.debug("Retrieved " + gauges.size() + " gauges.");
+
+        return gauges;
+    }
+
+
+    protected Gauge buildGauge(Element ele) {
+        String name     = ele.getAttribute("name");
+        String lowerStr = ele.getAttribute("lower");
+        String upperStr = ele.getAttribute("upper");
+
+        if (lowerStr != null && upperStr != null) {
+            try {
+                return new GaugeImpl(
+                    name,
+                    Double.valueOf(lowerStr),
+                    Double.valueOf(upperStr));
+            }
+            catch (NumberFormatException nfe) {
+                logger.warn("Error while Gauge creation: " + nfe.getMessage());
+            }
+        }
+
+        return null;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :