Develop Reference

How can I add a timer to get GPS location?

I am a beginner, and I have 2 question :-
I with below code get gps location now want add a timer to code for any 10 Min get gps and save file GPS.json
How can share file gps.json for use in other class this project ?
My code don't problem i tested and for save string used Json format.
Please help me
MyLocationListener class
private class myLocationListener implements LocationListener{
#Override
public void onLocationChanged(Location location) {
// TODO Auto-generated method stub
if(location!=null){
locManager.removeUpdates(locListener);
String longitude = "Longitude: " +location.getLongitude();
String latitude = "Latitude: " +location.getLatitude();
String altitiude = "Altitiude: " + location.getAltitude();
String ACRY ="ACR:" + location.getAccuracy();
try {
JSONObject jsonObject = new JSONObject();
JSONArray jsonArray = new JSONArray();
JSONObject record = new JSONObject();
record.put("longitude", longitude);
record.put("latitude", latitude);
record.put("altitiude", altitiude);
record.put("ACRY", ACRY);
jsonArray.put(record);
jsonObject.put("location", jsonArray);
File root = new File(Environment.getExternalStorageDirectory() + "/Android/test/data");
File gpxfile = new File(root((" Gps.json")));
FileOutputStream fileOutputStream = new FileOutputStream(gpxfile);
byte[] in = (jsonArray.toString().getBytes() );
fileOutputStream.write(in);
fileOutputStream.close();
} catch (Exception e) {
Toast.makeText(context,e.getMessage(),Toast.LENGTH_SHORT).show();
e.printStackTrace();
}
}
}
#Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}

I prvoide some you can change according your needs.
public void turnGPSOn() {
String provider = Settings.Secure.getString(getContentResolver(),
Settings.Secure.LOCATION_PROVIDERS_ALLOWED);
if (!provider.contains("gps")) {
final Intent poke = new Intent();
poke.setClassName("com.android.settings",
"com.android.settings.widget.SettingsAppWidgetProvider");
poke.addCategory(Intent.CATEGORY_ALTERNATIVE);
poke.setData(Uri.parse("3"));
sendBroadcast(poke);
}
}
private class MyTimerTask extends TimerTask {
#Override
public void run() {
runOnUiThread(new Runnable() {
#Override
public void run() {
// code to get and send location information
locManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
if (!locManager
.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
turnGPSOn();
}
try {
locManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 1000, 10,
locationListener);
} catch (Exception ex) {
turnGPSOff();
}
}
});
}
}
private void updateWithNewLocation(Location location) {
String latLongString = "";
try {
if (location != null) {
Log.e("test", "gps is on send");
latitude = Double.toString(location.getLatitude());
longitude = Double.toString(location.getLongitude());
Log.e("test", "location send");
locManager.removeUpdates(locationListener);
latLongString = "Lat:" + latitude + "\nLong:" + longitude;
Log.w("CurrentLocLatLong", latLongString);
} else {
latLongString = "No location found";
}
} catch (Exception e) {
}
}
private final LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
updateWithNewLocation(location);
}
public void onProviderDisabled(String provider) {
updateWithNewLocation(null);
}
public void onProviderEnabled(String provider) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
};
Calling the timer :
long gpsTimeInterval=2000;
void startTimer()
{
myTimer = new Timer();
myTimerTask = new MyTimerTask();
myTimer.scheduleAtFixedRate(myTimerTask, 0,
gpsTimeInterval);
}
and i hope you add internet permission into android manifest file.

get location data from service?

I try to make a locationing service but somehow i cant make it work.
Lat and Lng are always NULL.
I had some exceptions on locManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locListener); so i put it inside a run() method, now exception is gone. What could be the problem?
So what is the solution to make a locationing service work?
Code:
public class LocationService extends Service {
private Timer timer = new Timer();
private LocationManager locManager;
private LocationListener locListener = new MyLocationListener();
private String latitude;
private String longitude;
private String providerToSend;
Messenger messenger;
Timer t = new Timer();
#Override
public IBinder onBind(Intent arg0) {
return null;
}
public void onCreate() {
super.onCreate();
locListener = new MyLocationListener();
locationProviderInit();
startService();
}
#Override
public void onDestroy() {
super.onDestroy();
shutdownService();
}
private void startService() {
locManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
String token = new SharedPreffer(this).loadPreferences("token");
Log.d("Debug - token: ", "Van Token: " + token);
t.schedule(new TimerTask() {
#Override
public void run() {
locationProviderInit();
if (latitude != null && longitude != null) {
Log.d("Debug - lat: ", latitude);
Log.d("Debug - lng: ", longitude);
} else {
Log.d("Debug - lat and lng are: ", "NULL");
}
}
}, 0, 5000);
}
private void locationProviderInit() {
new Runnable() {
#Override
public void run() {
try {
boolean gps_enabled = locManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
boolean network_enabled = locManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
if (gps_enabled) {
locManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locListener);
providerToSend = LocationManager.GPS_PROVIDER;
}
if (network_enabled) {
locManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locListener);
providerToSend = LocationManager.NETWORK_PROVIDER;
}
} catch (Exception e) {
Log.d("Debug", e.toString());
}
}
};
}
class MyLocationListener implements LocationListener {
public void onLocationChanged(Location location) {
if (location != null) {
longitude = Double.toString(location.getLongitude());
latitude = Double.toString(location.getLatitude());
}
}
public void onProviderDisabled(String arg) {
}
public void onProviderEnabled(String arg) {
}
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}
private void shutdownService() {
if (timer != null)
timer.cancel();
Log.i(getClass().getSimpleName(), "Timer stopped!!!");
}
}

you don't execute the Runnable in locationProviderInit...

Have you tried to put a debug message inside the method run() within the Runnable object, and see if it has been ever executed?
Defining a Runnable instance without using it ,e.g. within a thread, won't work.
Here are few examples of open source GPS logging services that you can use as guide.
GPSLoggerService
GPSLoggingService

send xml file to local server in android

I want to send two variables (lat and longi) in xml file to local server, client code in calle d when location is changed using telnet. when i change location it says "Unfortunately, yourapp has stopped". I am using post method. I am newbii for client server code in android. Please any one help me....
this is my code
String responseBody;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/* Use the LocationManager class to obtain GPS locations */
LocationManager mlocManager =
(LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
/* Class My Location Listener */
public class MyLocationListener implements LocationListener
{
double lat, longi;
public void onLocationChanged(Location loc) {
lat = loc.getLatitude();
longi = loc.getLongitude();
String Text = "My current location is: "+"Latitude = "+lat+"Longitude = "+longi;
Toast.makeText( getApplicationContext(), Text, Toast.LENGTH_LONG).show();
// problem starts here
try
{
String s = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
+"<lat>" + lat +"</name>\n"
+"<long>" + longi + "</number>\n";
String url = "http://localhost:8080/android/test.php?data="+s;
HttpClient httpclient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(URI.create(url));
httpPost.setHeader("Content-type","text/xml; charset=ISO-8859-1");
ResponseHandler<String> responseHandler = new BasicResponseHandler();
responseBody = httpclient.execute(httpPost, responseHandler);
}
catch(IOException e)
{
e.printStackTrace();
}
}
public void onProviderDisabled(String provider) {
Toast.makeText( getApplicationContext(), "Gps Disabled", Toast.LENGTH_SHORT ).show();
}
public void onProviderEnabled(String provider) {
Toast.makeText( getApplicationContext(), "Gps Enabled", Toast.LENGTH_SHORT).show();
}
public void onStatusChanged(String provider, int status, Bundle extras)
{
}
}/* End of Class MyLocationListener */

Android: requestLocationUpdates throws exception

I'm trying to get periodically the user position via GPS in Android and send the data to a remote DB, but I get the exception: Can't create handler inside thread that has not called Looper.prepare().
The method that retrieves the position is in a remote service, and it's pretty basic:
private void dumpLocationLog() {
LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
Looper.myLooper().prepare();
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000L, 500.0f ,this);
retrieveUserId();
sendData(user_id);
}
I tried calling Looper.myLooper().prepare(); but it still does not work.
I guess I have to implement a Looper here but I don't know how as I'm still pretty newbie with Android.
This is the full code of my service:
public class LocationLoggingService extends Service {
String latString, lngString;
Double latitude, longitude;
Date durationDate;
String user_id;
public String username;
private Handler serviceHandler;
private Task myTask = new Task();
#Override
public IBinder onBind(Intent i) {
Log.d(getClass().getSimpleName(), "onBind()");
username = i.getStringExtra("username");
return myRemoteLocationServiceStub;
}
private IMyRemoteLocationLoggingService.Stub myRemoteLocationServiceStub = new IMyRemoteLocationLoggingService.Stub() {
public void dumpLocationLog() throws RemoteException {
LocationLoggingService.this.dumpLocationLog();
}
};
#Override
public void onCreate() {
super.onCreate();
Log.d(getClass().getSimpleName(), "onCreate()");
}
#Override
public void onDestroy() {
super.onDestroy();
serviceHandler.removeCallbacks(myTask);
serviceHandler = null;
Log.d(getClass().getSimpleName(), "onDestroy()");
}
#Override
public void onStart(Intent intent, int startId) {
username = intent.getStringExtra("username");
super.onStart(intent, startId);
serviceHandler = new Handler();
serviceHandler.postDelayed(myTask, 1000L);
Log.d(getClass().getSimpleName(), "onStart()");
}
class Task implements Runnable {
public void run() {
try {
myRemoteLocationServiceStub.dumpLocationLog();
} catch (RemoteException e) {
e.printStackTrace();
}
serviceHandler.postDelayed(this, 5000L);
Log.i(getClass().getSimpleName(), "Calling the dumpLocationLog");
}
}
public void retrieveUserId() {
ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("username", username));
String response = null;
try {
response = CustomHttpClient.executeHttpPost(
"http://10.0.2.2/science/getUserId.php", postParameters);
String res = response.toString();
res = res.replaceAll("\\s+", "");
if (!res.equals("0")) {
Log.d(getClass().getSimpleName(),
"Successfully retrieved user_id");
user_id = res;
} else {
Log.d(getClass().getSimpleName(), "Error retrieving user_id");
}
} catch (Exception e) {
}
}
private void sendData(String user_id) {
ArrayList<NameValuePair> postParameters = new ArrayList<NameValuePair>();
postParameters.add(new BasicNameValuePair("user_id", user_id));
postParameters.add(new BasicNameValuePair("latitude", latString));
postParameters.add(new BasicNameValuePair("longitude", lngString));
String response = null;
try {
response = CustomHttpClient.executeHttpPost(
"http://10.0.2.2/science/sendLocationData.php",
postParameters);
String res = response.toString();
res = res.replaceAll("\\s+", "");
if (res.equals("1")) {
Log.d(getClass().getSimpleName(), "Insertado en DB!");
} else {
Log.d(getClass().getSimpleName(), "Error insertando en la DB");
}
} catch (Exception e) {
}
}
LocationListener myLocationListener = new LocationListener () {
#Override
public void onLocationChanged(Location location) {
if (location != null) {
android.os.Debug.waitForDebugger();
latitude = location.getLatitude();
longitude = location.getLongitude();
latString = Double.toString(latitude);
lngString = Double.toString(longitude);
Log.d("Location: ", getClass().getSimpleName());
Log.d(latString, getClass().getSimpleName());
Log.d(lngString, getClass().getSimpleName());
}
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
};
private void dumpLocationLog() {
LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000L, 500.0f, myLocationListener);
retrieveUserId();
sendData(user_id);
}
public static String create_datestring(String timestring)
throws java.text.ParseException {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss",
Locale.US);
Date dt = null;
Calendar c = Calendar.getInstance();
try {
dt = sdf.parse("2011-03-01 17:55:15");
c.setTime(dt);
System.out.println(c.getTimeInMillis());
System.out.println(dt.toString());
} catch (ParseException e) {
System.err.println("There's an error in the Date!");
}
return dt.toString();
}
}
Thanks a lot in advance!

The proper way to use the message looper is described in its doc with a code sample here

Well finally the solution is:
Class LoggingService.java (this is my service):
private void dumpLocationLog() {
new DumpLocationLog(context, latString, lngString).start();
Log.d(latString, getClass().getSimpleName());
Log.d(lngString, getClass().getSimpleName());
retrieveUserId();
sendData(user_id);
}
Then in DumpLocationLog.java:
public class DumpLocationLog extends Thread {
LocationManager lm;
LocationHelper loc;
String latString, lngString = null;
public DumpLocationLog(Context context, String latString, String lngString) {
loc = new LocationHelper();
lm = (LocationManager)context.getSystemService(Context.LOCATION_SERVICE);
}
public void run() {
Looper.prepare();
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000L, 500.0f, loc);
Looper.loop();
}
}
Then finally the LocationHelper for the LocationListener interface:
public class LocationHelper implements LocationListener {
public String latString, lngString;
public Double latitude, longitude;
#Override
public void onLocationChanged(Location location) {
if (location != null) {
latitude = location.getLatitude();
longitude = location.getLongitude();
LocationLoggingService.latString = Double.toString(latitude);
LocationLoggingService.lngString = Double.toString(longitude);
}
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
}
It works like a charm but I have realized, that when listening for locations, it's creating threads non-stop and never closing the former ones; I mean that every time it checks for location, it creates a new thread and after X minutes, there are hundreds of threads.
Anybody knows why?

What I was suggesting you do was
class DumpLocationLog extends Thread
{
public void run()
{
LocationManager lm = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000L, 500.0f ,/* FIXME this */);
retrieveUserId();
sendData(user_id);
}
}
Then, from wherever you had been calling dumpLocationLog(), use runOnUiThread(new DumpLocationLog()) instead.

You can use this approach:
class DumpLocationLog extends Thread
{
public void run()
{
Looper.prepare();
mLooper = Looper.myLooper();
lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000L, 500.0f ,mLooper);
retrieveUserId();
sendData(user_id);
Looper.loop();
}
public void stop()
{
mLooper.quit();
}
}

Configuring frequency of notifications for requesting location updates

I'm trying to resolve a small problem:
mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 120000, 0, mLocationListener);
So I assumed that mLocationListener should wait for 2 mainutes before calling it's onLocationChanged method. However, the method is called right after I send geo fix updates to emulator, every time I do it. Did I misunderstand the android developers guide, and do I have to to use timers or anything similar for organizing update rate I need?

I think you're confused as to how the updates work. You can't tell the GPS hardware to send you an update at a specific time in the future. You can only give it guidelines on when you'd like to be updated. With the minTime you're saying you don't want updates more frequently than every 2 minutes, but then you're using a min distance of zero when you setup your listener. That tells the underlying GPS driver to send you an update whenever the location changes distance by any amount. That's why you're getting updates immediately when you send in a new point.

Well after some research and meditation :) I've come up with something like this: a service that can run in two modes (depending on the listenPeriod variable): 1) simply process coordinates once and shut self down afterwards (listenPeriod=0); 2) and process coordinates with specified rate (listenPeriod>0) until the service will be shut down.
GPSTracer.listenPeriod = 120000;
comp = new ComponentName(context.getPackageName(), GPSTracer.class.getName());
GPSTracer.iGPSTracer = new Intent(context, GPSTracer.class.getClass());
GPSTracer.iGPSTracer.setComponent(comp);
service=context.startService(GPSTracer.iGPSTracer);
So I have to initialize the listenPeriod variable before I start my service. And the service part looks like this:
public class GPSTracer extends Service {
public static Intent iGPSTracer;
public static volatile Location mLocation = null;
public static volatile LocationListener mLocationListener = null;
public static LocationManager mLocationManager = null;
public static long listenPeriod = 0;
Timer mTimer = null;
Handler mHandler = new Handler(){
#Override
public void handleMessage(Message msg) {
if(msg.arg1 == 1)
{
if(GPSTracer.mLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER))
{
GPSTracer.mLocationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 120000, 100, GPSTracer.mLocationListener);
}
else if(GPSTracer.mLocationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER))
{
GPSTracer.mLocationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 120000, 100, GPSTracer.mLocationListener);
}
else
{
List<NameValuePair> gpsData = new ArrayList<NameValuePair>();
gpsData.add(new BasicNameValuePair("Error", "No location provider"));
stopSelf();
}
}
else if(msg.arg1 == 0)
{
GPSTracer.mLocationManager.removeUpdates(GPSTracer.mLocationListener);
}
};
};
TimerTask selfStopTask = new TimerTask() {
#Override
public void run() {
stopSelf();
}
};
TimerTask mTimerTask = new TimerTask() {
#Override
public void run() {
//Message mMessage = new Message();
//mHandler.sendMessage(mMessage);
if(mLocation == null)
{
mLocation = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if(mLocation == null)
{
mLocation = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
}
}
if(mLocation != null)
{
List<NameValuePair> gpsData = new ArrayList<NameValuePair>();
gpsData.add(new BasicNameValuePair("Latitude", (new Double(mLocation.getLatitude())).toString()));
gpsData.add(new BasicNameValuePair("Longitude", (new Double(mLocation.getLongitude())).toString()));
gpsData.add(new BasicNameValuePair("Provider", mLocation.getProvider()));
}
else
{
List<NameValuePair> gpsData = new ArrayList<NameValuePair>();
gpsData.add(new BasicNameValuePair("Error", "Location is unknown"));
}
}
};
#Override
public void onCreate() {
mLocationManager = (LocationManager)getSystemService(LOCATION_SERVICE);
mLocationListener = new GPSListener(getApplicationContext());
};
#Override
public void onStart(Intent intent, int startId) {
Message mMessage = new Message();
mMessage.arg1 = 1;
mHandler.sendMessage(mMessage);
if(listenPeriod == 0)
{
mTimer = new Timer("GPSTask");
mTimer.schedule(mTimerTask, 0);
mTimer.schedule(selfStopTask, 60000);
}
else if(listenPeriod>0)
{
mTimer = new Timer("GPSTask");
mTimer.schedule(mTimerTask, 0, listenPeriod);
}
};
#Override
public void onDestroy() {
Message mMessage = new Message();
mMessage.arg1 = 0;
mHandler.sendMessage(mMessage);
//GPSTracer.mLocationManager.removeUpdates(GPSTracer.mLocationListener);
iGPSTracer = null;
mTimer.cancel();
mTimerTask.cancel();
mTimer = null;
mTimerTask = null;
mLocationListener = null;
mLocationManager = null;
};
#Override
public IBinder onBind(Intent arg0) {
// TODO Auto-generated method stub
return null;
}
}
and implementation of LocationListener:
public class GPSListener implements LocationListener{
Context context;
public GPSListener(Context appContext) {
context = appContext;
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
}
#Override
public void onLocationChanged(Location location) {
//GPSTracer.mLocationManager.removeUpdates(GPSTracer.mLocationListener);
GPSTracer.mLocation = location;
}
}
I hope it will help someone...)
P.S. thanks to Dave MacLean and EboMike!; and feel free to ask questions;)