joachimeichborn.geotag.geocode.MapQuestGeocoder.java Source code

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Here is the source code for joachimeichborn.geotag.geocode.MapQuestGeocoder.java

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/*
GeoTag
    
Copyright (C) 2015  Joachim von Eichborn
    
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 joachimeichborn.geotag.geocode;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.json.Json;
import javax.json.JsonObject;
import javax.json.JsonReader;
import javax.json.JsonString;

import org.apache.commons.lang3.StringUtils;

import joachimeichborn.geotag.model.Coordinates;
import joachimeichborn.geotag.model.Geocoding;

/**
 * Geocoder that provides the data of OpenStreetMap Nominatim, but seemingly
 * without restrictions on the number of queries that can be submitted
 * 
 * @author Joachim von Eichborn
 */
public class MapQuestGeocoder implements Geocoder {
    private final static String GEOCODE_URL = "http://open.mapquestapi.com/nominatim/v1/reverse.php?format=json&accept-language=de,en&addressdetails=1&zoom=18&lat=%f&lon=%f";

    public static enum LocationType {
        COUNTRY_CODE(new String[] { "country_code" }), //
        COUNTRY_NAME(new String[] { "country" }), //
        PROVINCE_STATE(new String[] { "state" }), //
        SUBLOCATION(new String[] { "state_district" }), //
        CITY(new String[] { "city", "village" }), //
        SUBURB(new String[] { "suburb" });

        private List<String> identifiers;

        LocationType(final String[] aIdentifiers) {
            identifiers = Arrays.asList(aIdentifiers);
        }

        public List<String> getIdentifiers() {
            return identifiers;
        }
    }

    private static final Logger logger = Logger.getLogger(MapQuestGeocoder.class.getSimpleName());

    public Geocoding queryPosition(final Coordinates aPosition) {
        final JsonObject jsonRepresentation = getGeocodeResult(aPosition);

        if (jsonRepresentation != null) {
            return extractLocationInformation(jsonRepresentation);
        }

        return null;
    }

    private Geocoding extractLocationInformation(final JsonObject aJsonRepresentation) {
        final JsonString location = aJsonRepresentation.getJsonString("display_name");
        final JsonObject addressDetails = aJsonRepresentation.getJsonObject("address");

        return createTextualRepresentation(location.getString(), addressDetails);
    }

    private Geocoding createTextualRepresentation(final String aLocation, final JsonObject aAddressDetails) {
        final Geocoding.Builder builder = new Geocoding.Builder();

        builder.setCountryCode(getMatchingContent(LocationType.COUNTRY_CODE, aAddressDetails));
        builder.setCountryName(getMatchingContent(LocationType.COUNTRY_NAME, aAddressDetails));
        builder.setProvinceState(getMatchingContent(LocationType.PROVINCE_STATE, aAddressDetails));
        builder.setSublocation(getMatchingContent(LocationType.SUBLOCATION, aAddressDetails));
        final List<String> city = new LinkedList<>();
        city.add(getMatchingContent(LocationType.CITY, aAddressDetails));
        city.add(getMatchingContent(LocationType.SUBURB, aAddressDetails));
        builder.setCity(StringUtils.join(city, ", "));
        builder.setLocationName(aLocation);

        return builder.build();
    }

    private String getMatchingContent(final LocationType aLocationType, final JsonObject aAddressDetails) {
        for (final String identifier : aLocationType.getIdentifiers()) {
            final JsonString value = aAddressDetails.getJsonString(identifier);
            if (value != null) {
                return value.getString();
            }
        }

        return null;
    }

    private JsonObject getGeocodeResult(final Coordinates aPosition) {
        URL url;
        try {
            url = new URL(
                    String.format(Locale.ENGLISH, GEOCODE_URL, aPosition.getLatitude(), aPosition.getLongitude()));
        } catch (MalformedURLException e) {
            logger.log(Level.SEVERE, "Initializing URL \"" + GEOCODE_URL + "\" failed", e);
            return null;
        }

        return makeRequest(url);
    }

    private JsonObject makeRequest(final URL aUrl) {
        JsonObject jsonRepresentation = null;
        try (final InputStream is = aUrl.openStream(); final JsonReader rdr = Json.createReader(is)) {
            jsonRepresentation = rdr.readObject();
        } catch (final IOException e) {
            logger.fine("Receiving textual representation failed: " + e.getMessage());
        }

        return jsonRepresentation;
    }
}