us.fatehi.pointlocation6709.parse.PointLocationParser.java Source code

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Here is the source code for us.fatehi.pointlocation6709.parse.PointLocationParser.java

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/*
 *
 * Point Location 6709
 * http://github.com/sualeh/pointlocation6709
 * Copyright (c) 2007-2014, Sualeh Fatehi.
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 */
package us.fatehi.pointlocation6709.parse;

import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.math.NumberUtils;

import us.fatehi.pointlocation6709.Latitude;
import us.fatehi.pointlocation6709.Longitude;
import us.fatehi.pointlocation6709.PointLocation;

/**
 * Parses objects from strings.
 *
 * @author Sualeh Fatehi
 */
public final class PointLocationParser {

    /**
     * Parses a string representation of the point location.
     *
     * @param representation
     *        String representation of the point location
     * @return Point location
     * @throws ParserException
     *         On an exception
     */
    public static PointLocation parsePointLocation(final String representation) throws ParserException {
        if (StringUtils.isBlank(representation)) {
            throw new ParserException("No point location value provided");
        }
        if (!StringUtils.endsWith(representation, "/")) {
            throw new ParserException("Point location value must be terminated with /");
        }

        final PointLocationParser parser = new PointLocationParser();
        final CoordinateParser coordinateParser = new CoordinateParser();
        // Split by group
        final List<String> tokens = parser.split(representation);
        if (tokens.size() != 4) {
            throw new ParserException("Cannot parse " + representation);
        }

        final Latitude latitude = coordinateParser.parseLatitude(tokens.get(0));
        final Longitude longitude = coordinateParser.parseLongitude(tokens.get(1));
        final double altitude = NumberUtils.toDouble(tokens.get(2));
        final String coordinateReferenceSystemIdentifier = StringUtils.trimToEmpty(tokens.get(3));

        final PointLocation pointLocation = new PointLocation(latitude, longitude, altitude,
                coordinateReferenceSystemIdentifier);
        return pointLocation;
    }

    private final Pattern patternCoordinates = Pattern.compile("([NSEW\\+\\-]\\d+\\.?\\d*)");
    private final Pattern patternCRS = Pattern.compile(".*CRS(.*)\\/");

    private List<String> split(final String representation) throws ParserException {
        final List<String> tokens = new ArrayList<>();

        final Matcher matcherCoordinates = patternCoordinates.matcher(representation);
        while (matcherCoordinates.find()) {
            final String token = matcherCoordinates.group(1);
            if (StringUtils.isNotBlank(token)) {
                tokens.add(token);
            }
        }
        if (tokens.size() < 2) {
            throw new ParserException("Latitude and longitude need to be provided in " + representation);
        }
        if (tokens.size() == 2) {
            // Add altitude
            tokens.add("0");
        }

        final Matcher matcherCRS = patternCRS.matcher(representation);
        while (matcherCRS.find()) {
            final String token = matcherCRS.group(1);
            if (StringUtils.isNotBlank(token)) {
                tokens.add(token);
            }
        }
        if (tokens.size() == 3) {
            // Add CRS
            tokens.add("");
        }

        return tokens;
    }

}