view flys-client/src/main/java/de/intevation/flys/client/server/ChartOutputServiceImpl.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 2867a0192aed
children
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package de.intevation.flys.client.server;

import java.io.OutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import org.w3c.dom.Document;

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.utils.ClientProtocolUtils;

import de.intevation.artifacts.httpclient.http.HttpClient;
import de.intevation.artifacts.httpclient.http.HttpClientImpl;


/**
 * This service is used to request a chart from the artifact server. The
 * response is directed directly to the output stream, so the image that is
 * retrieved is displayed in the UI afterwards.
 *
 * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
 */
public class ChartOutputServiceImpl
extends      HttpServlet
{
    private static final Logger logger =
        Logger.getLogger(ChartOutputServiceImpl.class);


    public void doGet(HttpServletRequest req, HttpServletResponse resp) {
        logger.info("ChartOutputServiceImpl.doGet");

        try {
            OutputStream out = resp.getOutputStream();

            String url = getServletContext().getInitParameter("server-url");

            String uuid   = req.getParameter("uuid");
            String type   = req.getParameter("type");
            String locale = req.getParameter("locale");

            prepareHeader(req, resp);

            Document request = ClientProtocolUtils.newOutCollectionDocument(
                uuid, type, type,
                ChartServiceHelper.getChartAttributes(prepareChartAttributes(req)));

            HttpClient client = new HttpClientImpl(url, locale);
            client.collectionOut(request, uuid, "chart", out);

            out.close();
            out.flush();
        }
        catch (IOException ioe) {
            logger.error(ioe, ioe);
        }
        catch (Exception e) {
            logger.error(e, e);
        }
    }


    protected Map<String, String> prepareChartAttributes(HttpServletRequest req) {
        Map<String, String> attr = new HashMap<String, String>();

        Map params = req.getParameterMap();

        attr.put("width", req.getParameter("width"));
        attr.put("height", req.getParameter("height"));
        attr.put("minx", req.getParameter("minx"));
        attr.put("maxx", req.getParameter("maxx"));
        attr.put("miny", req.getParameter("miny"));
        attr.put("maxy", req.getParameter("maxy"));
        attr.put("format", req.getParameter("format"));
        attr.put("km", req.getParameter("currentKm"));

        if (logger.isDebugEnabled()) {
            logger.debug("====== ZOOM VALUES =======");
            logger.debug("  min x: " + req.getParameter("minx"));
            logger.debug("  max x: " + req.getParameter("maxx"));
            logger.debug("  min y: " + req.getParameter("miny"));
            logger.debug("  max y: " + req.getParameter("maxy"));
        }

        return attr;
    }


    protected void prepareHeader(
        HttpServletRequest  req,
        HttpServletResponse resp
    ) {
        String export = req.getParameter("export");

        if (export != null && export.equals("true")) {
            String format = req.getParameter("format");

            if (format == null || format.length() == 0) {
                format = "png";
            }

            String fn = "chart_export" + getFileExtension(format);

            resp.setHeader("Content-Disposition", "attachment;filename=" + fn);
            resp.setHeader("Content-Type", getMimeType(format));
        }
    }


    protected String getFileExtension(String format) {
        if (format.equals("png")) {
            return ".png";
        }
        else if (format.equals("pdf")) {
            return ".pdf";
        }
        else if (format.equals("svg")) {
            return ".svg";
        }
        else if (format.equals("csv")) {
            return ".csv";
        }

        return ".png";
    }


    protected String getMimeType(String format) {
        if (format.equals("png")) {
            return "image/png";
        }
        else if (format.equals("pdf")) {
            return "application/pdf";
        }
        else if (format.equals("svg")) {
            return "svg+xml";
        }
        else if (format.equals("csv")) {
            return "text/plain";
        }

        return "image/png";
    }
}
// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :

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