Mercurial > dive4elements > river
diff flys-client/src/main/java/de/intevation/flys/client/server/GaugeInfoServiceImpl.java @ 2466:52a98e1653c1
Added a new RPC service to fetch gauge information.
flys-client/trunk@4173 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author | Ingo Weinzierl <ingo.weinzierl@intevation.de> |
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date | Tue, 20 Mar 2012 12:57:03 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/flys-client/src/main/java/de/intevation/flys/client/server/GaugeInfoServiceImpl.java Tue Mar 20 12:57:03 2012 +0000 @@ -0,0 +1,155 @@ +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.NodeList; + +import org.apache.log4j.Logger; + +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.GaugeInfoService; +import de.intevation.flys.client.shared.model.Gauge; +import de.intevation.flys.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 :