Google polyline decoder written in Java

Utils.java

import org.locationtech.jts.geom.*;

public class Utils {
  
	private static final double DEFAULT_PRECISION = 1E5;

	public static LineString decodePolyline(String encoded) {
		return decodePolyline(encoded, DEFAULT_PRECISION);
	}

	private static LineString decodePolyline(String encoded, double precision) {
		List<Coordinate> coordinates = new ArrayList<>();
		int index = 0;
		int lat = 0, lng = 0;

		while (index < encoded.length()) {
			int b, shift = 0, result = 0;
			do {
				b = encoded.charAt(index++) - 63;
				result |= (b & 0x1f) << shift;
				shift += 5;
			} while (b >= 0x20);
			int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
			lat += dlat;

			shift = 0;
			result = 0;
			do {
				b = encoded.charAt(index++) - 63;
				result |= (b & 0x1f) << shift;
				shift += 5;
			} while (b >= 0x20);
			int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
			lng += dlng;
			coordinates.add(new Coordinate(lng / precision, lat / precision));
		}
		LineString lineString = new GeometryFactory(new PrecisionModel(), 4326)
				.createLineString(coordinates.toArray(new Coordinate[coordinates.size()]));
		return lineString;
	}
  
}