source: josm/src/org/openstreetmap/josm/io/OsmReaderOld.java@ 66

package org.openstreetmap.josm.io;

import java.io.IOException;
import java.io.Reader;
import java.util.Collection;
import java.util.StringTokenizer;

import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;
import org.openstreetmap.josm.data.GeoPoint;
import org.openstreetmap.josm.data.osm.DataSet;
import org.openstreetmap.josm.data.osm.LineSegment;
import org.openstreetmap.josm.data.osm.Node;
import org.openstreetmap.josm.data.osm.OsmPrimitive;
import org.openstreetmap.josm.data.osm.Way;
import org.openstreetmap.josm.data.osm.visitor.AddVisitor;

/**
 * Reads the old osm 0.2 format. 
 * 
 * @author imi
 */
public class OsmReaderOld {

        /**
         * The data source from this reader.
         */
        public Reader source;

        /**
         * Construct a parser from a specific data source.
         * @param source The data source, as example a FileReader to read from a file.
         */
        public OsmReaderOld(Reader source) {
                this.source = source;
        }

        /**
         * Read the input stream and return a DataSet from the stream.
         */
        public DataSet parse() throws JDOMException, IOException {
                try {
                        final SAXBuilder builder = new SAXBuilder();
                        Element root = builder.build(source).getRootElement();
                        return parseDataSet(root);
                } catch (NumberFormatException nfe) {
                        throw new JDOMException("NumberFormatException. Probably a tag is missing.", nfe);
                } catch (NullPointerException npe) {
                        throw new JDOMException("NullPointerException. Probably a tag name mismatch.", npe);
                } catch (ClassCastException cce) {
                        throw new JDOMException("ClassCastException. Probably a tag does not contain the correct type.", cce);
                }
        }


        /**
         * Read one node.
         * @param e     The element to parse
         * @return              The Waypoint read from the element
         * @throws JDOMException In case of a parsing error.
         */
        private Node parseNode(Element e) throws JDOMException {
                Node data = new Node(new GeoPoint(
                        Double.parseDouble(e.getAttributeValue("lat")),
                        Double.parseDouble(e.getAttributeValue("lon"))));
                if (Double.isNaN(data.coor.lat) || 
                                data.coor.lat < -90 || data.coor.lat > 90 ||
                                data.coor.lon < -180 || data.coor.lon > 180)
                        throw new JDOMException("Illegal lat or lon value: "+data.coor.lat+"/"+data.coor.lon);
                parseCommon(data, e);
                return data;
        }

        /**
         * Parse any (yet unknown) object and return it.
         */
        private OsmPrimitive parseObject(Element e, DataSet data) throws JDOMException {
                if (e.getName().equals("node"))
                        return parseNode(e);
                else if (e.getName().equals("segment"))
                        return parseLineSegment(e, data);
                else if (e.getName().equals("way"))
                        return parseWay(e, data);
                else if (e.getName().equals("property")) {
                        parseProperty(e, data);
                        return null;
                }
                throw new JDOMException("unknown tag: "+e.getName());
        }
        
        /**
         * Read a data set from the element.
         * @param e     The element to parse
         * @return              The DataSet read from the element
         * @throws JDOMException In case of a parsing error.
         */
        private DataSet parseDataSet(Element e) throws JDOMException {
                DataSet data = new DataSet();
                AddVisitor visitor = new AddVisitor(data);
                for (Object o : e.getChildren()) {
                        Element child = (Element)o;
                        OsmPrimitive osm = parseObject(child, data);
                        if (osm != null)
                                osm.visit(visitor);
                }
                
                // clear all negative ids (new to this file)
                for (OsmPrimitive osm : data.allPrimitives())
                        if (osm.id < 0)
                                osm.id = 0;

                return data;
        }

        /**
         * Parse and return an line segment. The node information of the "from" and
         * "to" attributes must already be in the dataset.
         * @param e             The line segment element to parse.
         * @param data  The dataset to obtain the node information from.
         * @return The parsed line segment.
         * @throws JDOMException In case of parsing errors.
         */
        private LineSegment parseLineSegment(Element e, DataSet data) throws JDOMException {
                long startId = Long.parseLong(e.getAttributeValue("from"));
                long endId = Long.parseLong(e.getAttributeValue("to"));
                
                Node start = null, end = null;
                for (Node n : data.nodes) {
                        if (n.id == startId)
                                start = n;
                        if (n.id == endId)
                                end = n;
                }
                if (start == null || end == null)
                        throw new JDOMException("The 'from' or 'to' object has not been transfered before.");
                LineSegment ls = new LineSegment(start, end);
                parseCommon(ls, e);
                return ls;
        }

        /**
         * Parse and read a way from the element.
         *
         * @param e             The element that contain the way.
         * @param data  The DataSet to get segment information from.
         * @return              The parsed way.
         * @throws JDOMException In case of a parsing error.
         */
        private Way parseWay(Element e, DataSet data) throws JDOMException {
                Way way = new Way();
                parseCommon(way, e);
                for (Object o : e.getChildren("segment")) {
                        Element child = (Element)o;
                        long id = Long.parseLong(child.getAttributeValue("uid"));
                        LineSegment ls = findLineSegment(data.lineSegments, id);
                        way.segments.add(ls);
                }
                return way;
        }
        
        /**
         * Parse the common part (properties and uid) of the element.
         * @param data  To store the data in. 
         * @param e             The element to extract the common information.
         * @throws JDOMException In case of a parsing error
         */
        private void parseCommon(OsmPrimitive data, Element e) {
                String suid = e.getAttributeValue("uid");
                if (suid != null)
                        data.id = Long.parseLong(suid);
                
                String propStr = e.getAttributeValue("tags");
                if (propStr != null && !propStr.equals("")) {
                        StringTokenizer st = new StringTokenizer(propStr, ";");
                        while (st.hasMoreTokens()) {
                                String next = st.nextToken();
                                if (next.trim().equals(""))
                                        continue;
                                int equalPos = next.indexOf('=');
                                if (equalPos == -1)
                                        data.put(next, "");
                                else {
                                        String keyStr = next.substring(0, equalPos);
                                        data.put(keyStr, next.substring(equalPos+1));
                                }
                        }
                }
                
                String action = e.getAttributeValue("action");
                if ("delete".equals(action))
                        data.setDeleted(true);
                else if ("modify".equals(action))
                        data.modified = data.modifiedProperties = true;
                else if ("modify/property".equals(action))
                        data.modifiedProperties = true;
                else if ("modify/object".equals(action))
                        data.modified = true;
        }

        /**
         * Parse a property tag and assign the property to a previous found object.
         */
        private void parseProperty(Element e, DataSet data) throws JDOMException {
                long id = Long.parseLong(e.getAttributeValue("uid"));
                OsmPrimitive osm = findObject(data, id);
                String key = e.getAttributeValue("key");
                String value = e.getAttributeValue("value");
                if (value != null)
                        osm.put(key, value);
        }

        /**
         * Search for an object in the dataset by comparing the id.
         */
        private OsmPrimitive findObject(DataSet data, long id) throws JDOMException {
                for (OsmPrimitive osm : data.nodes)
                        if (osm.id == id)
                                return osm;
                for (OsmPrimitive osm : data.lineSegments)
                        if (osm.id == id)
                                return osm;
                for (OsmPrimitive osm : data.waies)
                        if (osm.id == id)
                                return osm;
                throw new JDOMException("Unknown object reference: "+id);
        }

        /**
         * Search for a segment in a collection by comparing the id.
         */
        private LineSegment findLineSegment(Collection<LineSegment> segments, long id) throws JDOMException {
                for (LineSegment ls : segments)
                        if (ls.id == id)
                                return ls;
                throw new JDOMException("Unknown line segment reference: "+id);
        }
}