org.mapsforge.poi.exchange.GeoJsonPoiPrinter.java Source code

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Here is the source code for org.mapsforge.poi.exchange.GeoJsonPoiPrinter.java

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/*
 * Copyright 2010 mapsforge.org
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.mapsforge.poi.exchange;

import java.util.Collection;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.mapsforge.poi.PointOfInterest;

/**
 * Provides method for generating GeoJson for points of interest.
 * 
 * @author weise
 * 
 */
public class GeoJsonPoiPrinter implements IPoiPrinter {

    private final Collection<PointOfInterest> pois;

    /**
     * @param pois
     *            collection of points of interest that shall be transformed into geo json
     *            format.
     */
    public GeoJsonPoiPrinter(Collection<PointOfInterest> pois) {
        this.pois = pois;
    }

    @Override
    public String print() {
        try {
            return buildJsonObject(pois).toString(4);
        } catch (JSONException e) {
            throw new RuntimeException(e.getMessage());
        }
    }

    private JSONObject buildJsonObject(Collection<PointOfInterest> pointsOfInterest) {
        JSONObject geoJsonObject = new JSONObject();
        JSONArray geometryCollection = new JSONArray();
        try {
            geoJsonObject.put("type", "FeatureCollection");
            for (PointOfInterest point : pointsOfInterest) {
                geometryCollection.put(pointJsonObject(point));
            }
            geoJsonObject.put("features", geometryCollection);
        } catch (JSONException e) {
            throw new RuntimeException(e.getMessage());
        }
        return geoJsonObject;
    }

    private JSONObject pointJsonObject(PointOfInterest poi) throws JSONException {
        JSONObject jsonPoint = new JSONObject();
        jsonPoint.put("type", "Point");
        JSONArray coordinates = new JSONArray();

        // order of longitude and latitude is important here!
        coordinates.put(poi.getLongitude());
        coordinates.put(poi.getLatitude());
        jsonPoint.put("coordinates", coordinates);

        JSONObject jsonProperties = new JSONObject();
        jsonProperties.put("name", poi.getName());
        jsonProperties.put("url", poi.getUrl());
        jsonProperties.put("id", poi.getId());

        JSONObject jsonFeature = new JSONObject();
        jsonFeature.put("type", "Feature");
        jsonFeature.put("geometry", jsonPoint);
        jsonFeature.put("properties", jsonProperties);

        return jsonFeature;
    }

}