source: osm/utils/josm/plugins/waypoints/src/WaypointReader.java@ 1495

package waypoints; 

import static org.openstreetmap.josm.tools.I18n.tr;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import org.openstreetmap.josm.data.coor.LatLon;
import org.openstreetmap.josm.data.osm.DataSet; // NW
import org.openstreetmap.josm.data.osm.Node; // NW
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;

import uk.co.wilson.xml.MinML2;


/**
 * Read waypoints from a GPX file and convert to nodes.
 */
public class WaypointReader {

        private static class Parser extends MinML2 {
                /**
                 * Current track to be read. The last entry is the current trkpt.
                 * If in wpt-mode, it contain only one GpsPoint.
                 */
            private DataSet dataSet;
                private LatLon currentLatLon;
                private String curWptName;
                private  boolean inName = false;

                // NW start     
                // data now has two components: the GPS points and an OsmDataLayer.
                // This is to allow us to convert waypoints straight to nodes.
                // The way this works is that waypoints with a name not beginning
                // with 0 - i.e. waypoints specially named - will be loaded in as
                // nodes, in addition to going into the gpx layer. Other waypoints will
                // only go into the gpx layer.
                public Parser()
                {
                        dataSet = new DataSet();
                }
                // NW end

                @Override public void startElement(String namespaceURI, 
                                String localName, String qName, Attributes atts) 
                                        throws SAXException {
                        if (qName.equals("wpt")) {
                                try {
                        double lat = Double.parseDouble(atts.getValue("lat"));
                        double lon = Double.parseDouble(atts.getValue("lon"));
                                if (Math.abs(lat) > 90)
                                        throw new SAXException
                                                (tr("Data error: lat value \"{0}\" is out of bound.", 
                                                        lat));
                                if (Math.abs(lon) > 180)
                                        throw new SAXException
                                                (tr("Data error: lon value \"{0}\" is out of bound.", 
                                                        lon));
                        currentLatLon = new LatLon(lat, lon);
                } catch (NumberFormatException e) {
                        e.printStackTrace();
                        throw new SAXException(e);
                }
                        }
                        else if (qName.equals("name")) {
                                inName = true;
                                curWptName = "";        
                        }       
                }

                @Override public void characters(char[] ch, int start, int length) {
                        // NW start
                        if (inName) {
                                curWptName = new String (ch,start,length);
                        }
                        // NW end
                }

                @Override public void endElement(String namespaceURI, String localName,
                                                                                String qName) {
                        if (qName.equals("wpt") && curWptName!="") { 
                                // create a new node from the latitude and longitude
                                System.out.println("Found a waypoint to convert to a node: " 
                                                                                + curWptName);
                                Node node = new Node(currentLatLon);
                                node.put("name",curWptName);
                                dataSet.nodes.add(node);
                        }
                        else if (qName.equals("name")) {
                                inName = false;
                        }
        }
        }

        /**
         * Parse and return the read data
         */
        public static DataSet parse(InputStream source) 
                        throws SAXException, IOException{
                Parser parser = new Parser();
                parser.parse(new InputStreamReader(source, "UTF-8"));
                return parser.dataSet;
        }
}