eu.vital.maps.server.servlets.KmlGenerator.java Source code

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Here is the source code for eu.vital.maps.server.servlets.KmlGenerator.java

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package eu.vital.maps.server.servlets;

/*
 * #%L
 * GWT Maps API V3 - Showcase
 * %%
 * Copyright (C) 2011 - 2012 GWT Maps API V3
 * %%
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * #L%
 */

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;

import eu.vital.maps.server.inmemoryqueue.TrafficEventsConsumer;

@Controller
public class KmlGenerator {//extends HttpServlet {

    private String[] example;

    @Autowired
    private TrafficEventsConsumer trafficEventsConsumer;

    /**
     * GET request - (no POST request below, that would need to be added)
     * 
     * @param request
     * @param response
     * @throws IOException
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws Exception {
        System.out.println(trafficEventsConsumer.peekTheMostImportantEvent());
        drawHtml(request, response);
    }

    /**
     * render some XML as a page
     * @param request
     * @param response
     * @throws IOException
     */
    private void drawHtml(HttpServletRequest request, HttpServletResponse response) throws IOException {

        String xml = getKml(request);

        // write the html to page
        response.setContentType("text/xml");
        PrintWriter out = response.getWriter();
        out.print(xml);
    }

    /**
     * get the kml stuff
     * 
     * @param request
     */
    private String getKml(HttpServletRequest request) {

        // TODO how to get a parameter - not used yet...
        @SuppressWarnings("unused")
        Long id = getParameterLong(request, "id");

        StringBuilder sb = new StringBuilder();
        sb.append("<?xml version=\"1.0\" standalone=\"yes\"?>\n");
        sb.append("<kml xmlns=\"http://earth.google.com/kml/2.2\">\n");
        sb.append("<Document>\n");
        sb.append("<name><![CDATA[<b>Demonstration of <br>multiple data files <br>on one map</b>]]></name>\n");
        sb.append("<Folder>\n");

        addNetworkLinks(sb);

        sb.append("</Folder>\n");
        sb.append("</Document>\n");
        sb.append("</kml>\n");

        return sb.toString();
    }

    /**
     * iterate the kml or kmz links I want
     * 
     * @param sb
     */
    private void addNetworkLinks(StringBuilder sb) {
        for (int i = 0; i < 3; i++) {
            addNetworkLinks(sb, i);
        }
    }

    /**
     * get the network link
     * @param sb
     * @param i
     */
    private void addNetworkLinks(StringBuilder sb, int i) {
        sb.append("<NetworkLink>\n");
        sb.append("<Link>\n");
        sb.append("<href>" + getLink(i) + "</href>\n");
        sb.append("</Link>\n");
        sb.append("</NetworkLink>\n");
    }

    /**
     * you could get these from app engine query dynamically, using parameters from the querystring
     * @param index
     */
    private String getLink(int index) {
        if (example == null) {
            example = new String[3];

            // TODO some encoding of the querystring & has to take place and maybe other chars
            //example[0] = "http://sites.google.com/a/cyclingthealps.com/cyclingthealps/routes/Flueelapass.kmz?attredirects=0&d=1";

            example[0] = "http://sites.google.com/a/cyclingthealps.com/cyclingthealps/routes/Flueelapass.kmz?attredirects=0&amp;d=1";
            example[1] = "http://www.mappingsupport.com/p/gmap4/helpfile/County_Line_trail.kml";
            example[2] = "http://www.mappingsupport.com/p/gmap4/helpfile/Teanaway_Peaks.kml";
        }
        String s = example[index];
        return s;
    }

    /**
     * grab a parameter from the request query string http://domain.tld?id=[0-9]+
     * 
     * @param req
     * @param parameter
     * @return returns a long
     */
    private Long getParameterLong(HttpServletRequest req, String parameter) {
        String s = req.getParameter(parameter);
        if (s == null) {
            return null;
        }
        Long id = null;
        try {
            id = Long.parseLong(s);
        } catch (NumberFormatException e) {
            e.printStackTrace();
        }
        return id;
    }

}