Mercurial > dive4elements > river
view flys-client/src/main/java/de/intevation/flys/client/server/DistanceInfoXML.java @ 5779:ebec12def170
Datacage: Add a pool of builders to make it multi threadable.
XML DOM is not thread safe. Therefore the old implementation only allowed one thread
to use the builder at a time. As the complexity of the configuration
has increased over time this has become a bottleneck of the whole application
because it took quiet some time to build a result. Furthermore the builder code path
is visited very frequent. So many concurrent requests were piled up
resulting in long waits for the users.
To mitigate this problem a round robin pool of builders is used now.
Each of the pooled builders has an independent copy of the XML template
and can be run in parallel.
The number of builders is determined by the system property
'flys.datacage.pool.size'. It defaults to 4.
author | Sascha L. Teichmann <teichmann@intevation.de> |
---|---|
date | Sun, 21 Apr 2013 12:48:09 +0200 |
parents | bc06a671ef60 |
children |
line wrap: on
line source
package de.intevation.flys.client.server; import java.io.InputStream; import java.io.IOException; import java.io.OutputStream; import org.w3c.dom.Document; import org.w3c.dom.Element; import org.apache.log4j.Logger; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; 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.artifacts.httpclient.http.response.StreamResponseHandler; /** * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a> */ public class DistanceInfoXML extends HttpServlet { private static final Logger logger = Logger.getLogger(DistanceInfoXML.class); public static final String ERROR_NO_DISTANCEINFO_FOUND = "error_no_distanceinfo_found"; public void doGet(HttpServletRequest req, HttpServletResponse resp) { logger.info("DistanceInfoXML.doGet"); String url = getServletContext().getInitParameter("server-url"); String river = req.getParameter("river"); String filter = req.getParameter("filter"); 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); if (filter != null && filter.length() > 0) { Element typeEl = ec.create("filter"); typeEl.setTextContent(filter); riverEl.appendChild(typeEl); } HttpClient client = new HttpClientImpl(url); try { InputStream in = (InputStream) client.callService( url, "distanceinfo", doc, new StreamResponseHandler()); OutputStream out = resp.getOutputStream(); byte[] b = new byte[4096]; int i; while ((i = in.read(b)) >= 0) { out.write(b, 0, i); } out.flush(); out.close(); } catch (ConnectionException ce) { logger.error(ce, ce); } catch (IOException ioe) { logger.error(ioe, ioe); } } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :