Saving lat longs from database to GPX file.Android

Question

I have created sqlite database which stores Latitude,Longitude and some other information like description.

Now I want to extract this information and write into a GPX file to my SD card for further analysis purpose. Anyone have an idea about how to do this?

Any helpful links, sources etc.?

Answer 1

Thanks friends. Above two links help me to solve my problem, Here is the code for writing database values to .kml file

try {
                                File root = Environment
                                        .getExternalStorageDirectory();
                                if (root.canWrite()) {
                                    File gpxfile = new File(root, ""
                                            + value + ".kml");
                                    FileWriter gpxwriter = new FileWriter(
                                            gpxfile);
                                    BufferedWriter out = new BufferedWriter(
                                            gpxwriter);
                                    out.write("<?xml version=\"1.0\" encoding=\"UTF-8\"?>"
                                            + "\n"
                                            + "<kml xmlns=\"http://www.opengis.net/kml/2.2\">"
                                            + "\n" + "<Folder>" + "\n");
                                    for (int i = 0; i < latarray.length; i++) {
                                        out.write("<Placemark>" + "\n"
                                                + "<name> Point "
                                                + i
                                                + "</name>"
                                                + "\n"
                                                + "<description>"
                                                + ""
                                                + discription[i]
                                                + "</description>"
                                                + "\n"
                                                + "<Point>"
                                                + "\n"
                                                + "<coordinates>"
                                                + ""
                                                + (lonarray[i] / (1E6))
                                                + ","
                                                + ""
                                                + (latarray[i] / (1E6))
                                                + ","
                                                + ""
                                                + accuarray[i]
                                                + "</coordinates>"
                                                + "\n"
                                                + " </Point>"
                                                + "\n"
                                                + "</Placemark>" + "\n");
                                    }
                                    out.write("</Folder>" + "\n" + "</kml>");
                                    out.close();
                                    mydb.close();
                                }
                            } catch (IOException e) {
                                Log.e("Cant write", "Could not write file "
                                        + e.getMessage());
                            }

and here is the example to read value from database

public int[] lattodraw() {
    // TODO Auto-generated method stub

    String[] columns = new String[] { KEY_ROWID, KEY_Latitude,
            KEY_Longitude, KEY_Accuracy, KEY_ROWID, KEY_Latitude,
            KEY_Longitude, KEY_Accuracy, KEY_Discription, KEY_North,
            KEY_East, KEY_South, KEY_West };
    Cursor locationCursor = ourDatabase.query(DATABASE_TABLE, columns,
            null, null, null, null, null);

    locationCursor.moveToFirst();
    int count = locationCursor.getCount();
    int latarray[] = new int[count];
    int i = 0;
    do {

        int latitude = (int) (locationCursor.getDouble(locationCursor
                .getColumnIndex(KEY_Latitude)) * 1E6);

        latarray[i] = latitude;
        i++;
    } while (locationCursor.moveToNext());
    locationCursor.close();
    return latarray;
}

Answer 2

The best solution I found so far for both writing and reading GPX is this one: http://sourceforge.net/projects/gpxparser/

Answer 3

here it is:

try {
    File root = Environment.getExternalStorageDirectory();
    if (root.canWrite()){
        File gpxfile = new File(root, "gpxfile.gpx");
        FileWriter gpxwriter = new FileWriter(gpxfile);
        BufferedWriter out = new BufferedWriter(gpxwriter);
        out.write("Hello world");
        out.close();
    }
} catch (IOException e) {
    Log.e(TAG, "Could not write file " + e.getMessage());
}