免费建立你自己的gps/gis系统

public class GPSLayer extends OMGraphicHandlerLayer {

private static String GPSDATA = "gpsData";

private static final double KT2MPS = 1852.0 / 3600.0;

private static final double speedVectorLengthInMinutes = 6;

private String gpsDataPath = "";

private float latitude, longitude, speed, course;

private OMGraphicList graphics = new OMGraphicList();;

private OMRect gpsPosition = new OMRect(0, 0, 0, 0, 10, 10);

private OMLine speedVector;

private OMText gpsText = new OMText(10, 20, "GPS Data",
OMText.JUSTIFY_LEFT);

private Timer timer;

public GPSLayer() {
gpsText.setFillPaint(Color.WHITE);
gpsText.setTextMatteColor(new Color(182, 235, 219));
gpsPosition.setFillPaint(Color.pink);
}

@Override
public void setProperties(String prefix, Properties props) {
super.setProperties(prefix, props);
gpsDataPath = props.getProperty(prefix + "." + GPSDATA);
// redraw every 5 secs
timer = new Timer(5000, this);
timer.start();

// emulate reading GPS data (threading issue here access to members not
// protected!)
new Thread(new Runnable() {
public void run() {
 try {
  BufferedReader in = new BufferedReader(new FileReader(
    gpsDataPath));
  String str;
  while ((str = in.readLine()) != null) {
   Thread.sleep(100);
   if (str.startsWith("$GPRMC")) {
    String[] fields = str.split(",");
    // utc_date = fields[1];
    double lat = Double.parseDouble(fields[3]);
    double degrees = Math.floor((lat / 100.0));
    double minute = (lat / 100.0) - degrees;
    lat = (degrees) + ((minute * 100.0) / 60);
    if (fields[4].equals("S"))
     lat = -lat;
    latitude = (float) lat;

    double lon = Double.parseDouble(fields[5]);
    degrees = Math.floor((lon / 100.0));
    minute = (lon / 100.0) - degrees;
    lon = (degrees) + ((minute * 100.0) / 60);
    if (fields[6].equals("W"))
     lon = -lon;
    longitude = (float) lon;

    speed = (float) (Double.parseDouble(fields[7]) * KT2MPS);

    if (!fields[8].equals("")) {
     course = (float) Double.parseDouble(fields[8]);
    }
    // could parse date but to lazy
    // date = fields[9];
   }
  }
  in.close();
 } catch (Exception e) {
  e.printStackTrace();
 }
}
}).start();
}

@Override
public synchronized OMGraphicList prepare() {
gpsPosition.setLocation(latitude, longitude, -5, -5, 5, 5);

// calc. speed vector length using OM GIS functions
LatLonPoint startPos = new LatLonPoint(latitude, longitude);
float length = (float) Length.KM.toRadians(speedVectorLengthInMinutes
 * ((speed * 3.6) / 60.0));
LatLonPoint endPos = startPos.getPoint(length, (float) ProjMath
 .degToRad(course));
speedVector = new OMLine(startPos.getLatitude(), startPos
 .getLongitude(), endPos.getLatitude(), endPos.getLongitude(),
 OMLine.LINETYPE_STRAIGHT);
// vec.addArrowHead(OMArrowHead.ARROWHEAD_DIRECTION_FORWARD, 100, 3, 1);
speedVector.setLinePaint(Color.DARK_GRAY);

graphics.clear();
// order of add determines what is rendered on top
graphics.add(speedVector);
graphics.add(gpsPosition);
gpsText.setData(String.format("GPS Data\n%4.2f Km/h",
 (speed * 3.60)));
graphics.add(gpsText);

graphics.project(getProjection());
return graphics;
}

@Override
public void actionPerformed(ActionEvent ae) {
doPrepare();
}
}