ingo@29: package de.intevation.flys.client.server;
ingo@29: 
ingo@29: import java.util.ArrayList;
ingo@29: import java.util.List;
ingo@29: 
ingo@29: import javax.xml.xpath.XPathConstants;
ingo@29: 
ingo@29: import org.w3c.dom.Document;
ingo@29: import org.w3c.dom.NodeList;
ingo@29: import org.w3c.dom.Node;
ingo@29: 
ingo@1367: import org.apache.log4j.Logger;
ingo@1367: 
ingo@29: import com.google.gwt.user.server.rpc.RemoteServiceServlet;
ingo@29: 
ingo@29: import de.intevation.artifacts.common.ArtifactNamespaceContext;
ingo@29: import de.intevation.artifacts.common.utils.XMLUtils;
ingo@29: 
ingo@29: import de.intevation.artifacts.httpclient.exceptions.ConnectionException;
ingo@29: import de.intevation.artifacts.httpclient.http.HttpClient;
ingo@29: import de.intevation.artifacts.httpclient.http.HttpClientImpl;
ingo@29: 
ingo@217: import de.intevation.flys.client.shared.exceptions.ServerException;
ingo@29: import de.intevation.flys.client.shared.model.DefaultRiver;
ingo@29: import de.intevation.flys.client.shared.model.River;
ingo@29: import de.intevation.flys.client.client.services.RiverService;
ingo@29: 
ingo@29: 
ingo@29: /**
ingo@29:  * This interface provides a method to list the supported rivers of the artifact
ingo@29:  * server.
ingo@29:  *
ingo@29:  * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
ingo@29:  */
ingo@29: public class RiverServiceImpl
ingo@29: extends      RemoteServiceServlet
ingo@29: implements   RiverService
ingo@29: {
ingo@1367:     private static final Logger logger =
ingo@1367:         Logger.getLogger(RiverServiceImpl.class);
ingo@1367: 
ingo@1367: 
ingo@29:     /** The XPath string that points to the rivers in the resulting document.*/
ingo@29:     public static final String XPATH_RIVERS = "/art:rivers/art:river";
ingo@29: 
ingo@217:     /** The error message key that is thrown if an error occured while reading
ingo@217:      * the supported rivers from server.*/
ingo@217:     public static final String ERROR_NO_RIVERS_FOUND = "error_no_rivers_found";
ingo@29: 
ingo@217: 
raimund@1425:     public River[] list(String locale)
ingo@217:     throws ServerException
ingo@217:     {
raimund@1425:         String url = getServletContext().getInitParameter("server-url");
raimund@1425: 
ingo@29:         Document doc      = XMLUtils.newDocument();
ingo@29: 
ingo@29:         XMLUtils.ElementCreator ec = new XMLUtils.ElementCreator(
ingo@29:             doc,
ingo@29:             ArtifactNamespaceContext.NAMESPACE_URI,
ingo@29:             ArtifactNamespaceContext.NAMESPACE_PREFIX);
ingo@29: 
ingo@29:         doc.appendChild(ec.create("action"));
ingo@29: 
raimund@1425:         HttpClient client = new HttpClientImpl(url, locale);
ingo@29: 
ingo@29:         try {
raimund@1425:             Document res = client.callService(url, "rivers", doc);
ingo@29: 
ingo@29:             NodeList rivers = (NodeList) XMLUtils.xpath(
ingo@29:                 res,
ingo@29:                 XPATH_RIVERS,
ingo@29:                 XPathConstants.NODESET,
ingo@29:                 ArtifactNamespaceContext.INSTANCE);
ingo@29: 
ingo@217:             if (rivers == null || rivers.getLength() == 0) {
ingo@217:                 throw new ServerException(ERROR_NO_RIVERS_FOUND);
ingo@217:             }
ingo@217: 
ingo@29:             int count = rivers.getLength();
ingo@29: 
ingo@29:             List<River> theRivers = new ArrayList<River>(count);
ingo@29: 
ingo@29:             for (int i = 0; i < count; i++) {
ingo@29:                 Node tmp = rivers.item(i);
ingo@29: 
ingo@29:                 String name = XMLUtils.xpathString(
ingo@29:                     tmp, "@art:name", ArtifactNamespaceContext.INSTANCE);
ingo@29: 
ingo@29:                 theRivers.add(new DefaultRiver(name));
ingo@29:             }
ingo@29: 
ingo@29:             return (River[]) theRivers.toArray(new River[count]);
ingo@29:         }
ingo@29:         catch (ConnectionException ce) {
ingo@1367:             logger.error(ce, ce);
ingo@29:         }
ingo@29: 
ingo@217:         throw new ServerException(ERROR_NO_RIVERS_FOUND);
ingo@29:     }
ingo@29: }
ingo@29: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :