brouter/brouter-map-creator/src/main/java/btools/mapcreator/OsmParser.java

package btools.mapcreator;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;
import java.util.zip.GZIPInputStream;

/**
 * Parser for OSM data
 *
 * @author ab
 */
public class OsmParser extends MapCreatorBase {
  private BufferedReader _br;

  private NodeListener nListener;
  private WayListener wListener;
  private RelationListener rListener;

  public void readMap(File mapFile,
                      NodeListener nListener,
                      WayListener wListener,
                      RelationListener rListener) throws Exception {

    this.nListener = nListener;
    this.wListener = wListener;
    this.rListener = rListener;

    if (mapFile == null) {
      _br = new BufferedReader(new InputStreamReader(System.in));
    } else {
      if (mapFile.getName().endsWith(".gz")) {
        _br = new BufferedReader(new InputStreamReader(new GZIPInputStream(new FileInputStream(mapFile))));
      } else {
        _br = new BufferedReader(new InputStreamReader(new FileInputStream(mapFile)));
      }
    }

    for (; ; ) {
      String line = _br.readLine();
      if (line == null) break;

      if (checkNode(line)) continue;
      if (checkWay(line)) continue;
      if (checkRelation(line)) continue;
      if (checkChangeset(line)) continue;
    }

    if (mapFile != null) {
      _br.close();
    }
  }


  private boolean checkNode(String line) throws Exception {
    int idx0 = line.indexOf("<node id=\"");
    if (idx0 < 0) return false;
    idx0 += 10;
    int idx1 = line.indexOf('"', idx0);

    long nodeId = Long.parseLong(line.substring(idx0, idx1));

    int idx2 = line.indexOf(" lat=\"");
    if (idx2 < 0) return false;
    idx2 += 6;
    int idx3 = line.indexOf('"', idx2);
    double lat = Double.parseDouble(line.substring(idx2, idx3));
    int idx4 = line.indexOf(" lon=\"");
    if (idx4 < 0) return false;
    idx4 += 6;
    int idx5 = line.indexOf('"', idx4);
    double lon = Double.parseDouble(line.substring(idx4, idx5));

    NodeData n = new NodeData(nodeId, lon, lat);

    if (!line.endsWith("/>")) {
      // read additional tags
      for (; ; ) {
        String l2 = _br.readLine();
        if (l2 == null) return false;

        int i2;
        if ((i2 = l2.indexOf("<tag k=\"")) >= 0) { // property-tag
          i2 += 8;
          int ri2 = l2.indexOf('"', i2);
          String key = l2.substring(i2, ri2);
          i2 = l2.indexOf(" v=\"", ri2);
          if (i2 >= 0) {
            i2 += 4;
            int ri3 = l2.indexOf('"', i2);
            String value = l2.substring(i2, ri3);

            n.putTag(key, value);
          }
        } else if (l2.indexOf("</node>") >= 0) { // end-tag
          break;
        }
      }
    }
    nListener.nextNode(n);
    return true;
  }


  private boolean checkWay(String line) throws Exception {
    int idx0 = line.indexOf("<way id=\"");
    if (idx0 < 0) return false;

    idx0 += 9;
    int idx1 = line.indexOf('"', idx0);
    long id = Long.parseLong(line.substring(idx0, idx1));

    WayData w = new WayData(id);

    // read the nodes
    for (; ; ) {
      String l2 = _br.readLine();
      if (l2 == null) return false;

      int i2;
      if ((i2 = l2.indexOf("<nd ref=\"")) >= 0) { // node reference
        i2 += 9;
        int ri2 = l2.indexOf('"', i2);
        long nid = Long.parseLong(l2.substring(i2, ri2));
        w.nodes.add(nid);
      } else if ((i2 = l2.indexOf("<tag k=\"")) >= 0) { // property-tag
        i2 += 8;
        int ri2 = l2.indexOf('"', i2);
        String key = l2.substring(i2, ri2);
        i2 = l2.indexOf(" v=\"", ri2);
        if (i2 >= 0) {
          i2 += 4;
          int ri3 = l2.indexOf('"', i2);
          String value = l2.substring(i2, ri3);
          w.putTag(key, value);
        }
      } else if (l2.indexOf("</way>") >= 0) { // end-tag
        break;
      }
    }
    wListener.nextWay(w);
    return true;
  }

  private boolean checkChangeset(String line) throws Exception {
    int idx0 = line.indexOf("<changeset id=\"");
    if (idx0 < 0) return false;

    if (!line.endsWith("/>")) {
      int loopcheck = 0;
      for (; ; ) {
        String l2 = _br.readLine();
        if (l2.indexOf("</changeset>") >= 0 || ++loopcheck > 10000) break;
      }
    }
    return true;
  }

  private boolean checkRelation(String line) throws Exception {
    int idx0 = line.indexOf("<relation id=\"");
    if (idx0 < 0) return false;

    idx0 += 14;
    int idx1 = line.indexOf('"', idx0);
    long rid = Long.parseLong(line.substring(idx0, idx1));

    RelationData r = new RelationData(rid);

    // read the nodes
    for (; ; ) {
      String l2 = _br.readLine();
      if (l2 == null) return false;

      int i2;
      if ((i2 = l2.indexOf("<member type=\"way\" ref=\"")) >= 0) { // node reference
        i2 += 24;
        int ri2 = l2.indexOf('"', i2);
        long wid = Long.parseLong(l2.substring(i2, ri2));
        r.ways.add(wid);
      } else if ((i2 = l2.indexOf("<tag k=\"")) >= 0) { // property-tag
        i2 += 8;
        int ri2 = l2.indexOf('"', i2);
        String key = l2.substring(i2, ri2);
        i2 = l2.indexOf(" v=\"", ri2);
        if (i2 >= 0) {
          i2 += 4;
          int ri3 = l2.indexOf('"', i2);
          String value = l2.substring(i2, ri3);
          r.putTag(key, value);
        }
      } else if (l2.indexOf("</relation>") >= 0) { // end-tag
        break;
      }
    }
    rListener.nextRelation(r);
    return true;
  }

}