view flys-client/src/main/java/de/intevation/flys/client/server/ChartOutputServiceImpl.java @ 4421:0b0f415203f0

Add new Filter class to change caching Add new Filter class to avoid caching of GWT nocache files in browsers and http proxies. The new Filter class NoCacheFilter sets http headers to stop the proxies and browesers from storing the nocache files.
author Björn Ricks <bjoern.ricks@intevation.de>
date Tue, 06 Nov 2012 13:32:06 +0100
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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