org.n52.ar.layar.LayarServlet.java Source code

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Here is the source code for org.n52.ar.layar.LayarServlet.java

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/**
 * Copyright 2012 52North Initiative for Geospatial Open Source Software GmbH
 *
 * 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.
 */
package org.n52.ar.layar;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;

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

import org.n52.ar.SirCallbackServlet;
import org.n52.ar.SirPOI;
import org.n52.sir.json.SearchResultElement;
import org.n52.sir.json.ServiceReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.fasterxml.jackson.core.JsonFactory;
import com.fasterxml.jackson.core.JsonGenerator;

/**
 * 
 * 
 * @author <a href="mailto:d.nuest@52north.org">Daniel Nst</a>
 * 
 */
public class LayarServlet extends SirCallbackServlet {

    private static Logger log = LoggerFactory.getLogger(LayarServlet.class);

    private static final String REQUEST_FORMAT = "application/json";

    /**
      * 
      */
    private static final long serialVersionUID = 3747559074882272526L;

    private JsonFactory factory;

    private String layerName = "opensensorsearch";

    public LayarServlet() {
        log.debug("NEW {}", this);
    }

    @Override
    protected SirPOI createPOI(SearchResultElement sre) {
        Hotspot h = new Hotspot();
        // poi.actions
        // poi.alt = calculate altitude?`
        // poi.attribution
        h.description = sre.getSensorDescription().getText();
        // poi.distance = calculate?
        h.id = sre.getSensorId();
        // poi.imageURL
        double[] latLon = sre.getSensorDescription().getBoundingBox().getCenter();
        h.lat = latLon[0];
        h.lon = latLon[1];
        ArrayList<ServiceReference> references = (ArrayList<ServiceReference>) sre.getServiceReferences();
        h.title = references.get(0).getServiceSpecificSensorId();

        return h;
    }

    /**
     * http://layar.com/documentation/browser/api/getpois-request/
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String userAgent = request.getHeader("User-agent");
        log.debug("User-agent={}", userAgent);

        /*
         * mandatory:
         */
        String userId = request.getParameter("userId");
        String version = request.getParameter("version");
        String countryCode = request.getParameter("countryCode");
        String lang = request.getParameter("lang");

        String action = request.getParameter("action");
        if (action == null) {
            // response.sendError(HttpServletResponse.SC_BAD_REQUEST,
            // "Missing parameter 'action'");
            // return;
            log.debug("No action given.");
        }

        String latParam = request.getParameter("lat");
        if (latParam == null) {
            response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Missing parameter 'lat'");
            return;
        }

        String lonParam = request.getParameter("lon");
        if (lonParam == null) {
            response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Missing parameter 'lon'");
            return;
        }

        String radiusParam = request.getParameter("radius");
        if (radiusParam == null) {
            response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Missing parameter 'radius'");
            return;
        }

        /*
         * optional:
         */
        String accurary = request.getParameter("accuracy");
        String pageKey = request.getParameter("pageKey");
        // String oauth_consumer_key =
        // request.getParameter("oauth_consumer_key");
        // String oauth_signature_method =
        // request.getParameter("oauth_signature_method");
        String radiolist = request.getParameter("RADIOLIST");
        String searchbox = request.getParameter("SEARCHBOX");
        String custom_slider = request.getParameter("CUSTOM_SLIDER");
        String checkboxlist = request.getParameter("CHECKBOXLIST");
        String localCountryCode = request.getParameter("localCountryCode");
        String alt = request.getParameter("alt"); // current altitude
        String recognizedReferenceImage = request.getParameter("recognizedReferenceImage");

        // convert parameters
        float lat = Float.parseFloat(latParam);
        float lon = Float.parseFloat(lonParam);
        double[] center = new double[] { lat, lon };
        float radius = Float.parseFloat(radiusParam);

        // get nearby sensors
        LayarResponse layarResponse = new LayarResponse();
        layarResponse.layer = request.getParameter("layerName");
        if (layarResponse.layer == null) {
            response.sendError(HttpServletResponse.SC_BAD_REQUEST, "Missing parameter 'layerName'");
            return;
        }

        response.setContentType("application/json; charset=utf-8");
        JsonGenerator generator = this.factory.createJsonGenerator(response.getWriter());
        generator.useDefaultPrettyPrinter();

        // query SIR
        try {
            Collection<SirPOI> pois = querySIR(center, radius, REQUEST_FORMAT);

            for (SirPOI sirPOI : pois) {
                if (sirPOI instanceof Hotspot) {
                    Hotspot h = (Hotspot) sirPOI;
                    layarResponse.hotspots.add(h);
                }
            }
        } catch (Exception e) {
            log.error("Error querying SIR.", e);
            layarResponse.errorCode = LayarResponse.CODE_ERROR;
            layarResponse.errorString = e.toString() + ": " + e.getMessage();
            layarResponse.showMessage = "Server side exception!";
        }

        // write response
        layarResponse.toJSON(generator);

        // clean up
        generator.close();
        response.flushBuffer();
    }

    public String getLayerName() {
        return this.layerName;
    }

    @Override
    public void init(ServletConfig servletConfig) throws ServletException {
        super.init(servletConfig);

        this.factory = new JsonFactory();

        log.info("Initialized " + this);
    }
}