Develop Reference

AsyncTask takes too much time the first time it executes

The first time the Asynctask executes takes 30 or more seconds. It happens when I enter the activity. After that, subsequents call to the Asyntask(when I enter the activity again from the previous activity) takes only 4 or 5 seconds, which I consider to be "acceptable".
Here is the code where I execute the AsyncTask
#Override
public void onLocationChanged(Location location) {
if (location!=null) {
mlastLocation=location;
double latitud=Double.parseDouble(getIntent().getStringExtra("latitud").replace("Latitud:", ""));
double longitud=Double.parseDouble(getIntent().getStringExtra("longitud").replace("Longitud:", ""));
LatLng origen= new LatLng(latitud,longitud);
LatLng destino=new LatLng(mlastLocation.getLatitude(),mlastLocation.getLongitude());
if (mCount==0) {
FillVariablesAsyncTask tareaAsincrona = new FillVariablesAsyncTask();
tareaAsincrona.execute(origen, destino);
mCount++;
}
}
}
And here the code of the AsyncTask, where onPostExecute updates members variables and update the UI.
private class FillVariablesAsyncTask extends AsyncTask<LatLng,Void,Document>{
#Override
protected Document doInBackground(LatLng... params) {
md=new GMapV2Direction();
LatLng origen=new LatLng(params[0].latitude,params[0].longitude);
LatLng destino=new LatLng(params[1].latitude,params[1].longitude);
Document doc = md.getDocument(origen, destino, GMapV2Direction.MODE_WALKING);
/*mUbicacionActual = md.getStartAddress(doc);
mDuration=md.getDurationText(doc);
mDistancia=md.getDistanceText(doc);*/
return doc;
}
#Override
protected void onPostExecute(Document doc) {
super.onPostExecute(doc);
mUbicacionActual = md.getStartAddress(doc);
mDuration=md.getDurationText(doc);
mDistancia=md.getDistanceText(doc);
if (mUbicacionActual!=null && mDistancia!=null && mDuration!=null) {
progressBar.setVisibility(View.GONE);
btnIr.setEnabled(true);
tvOrigenLatitud.setText("Latitud:"+String.valueOf(mlastLocation.getLatitude()));
tvOrigenLongitud.setText("Longitud"+String.valueOf(mlastLocation.getLongitude()));
tvDestino.setText("Destino:" + getIntent().getStringExtra("info").replace("Info:", ""));
tvDestinoLatitud.setText("Latitud:" + getIntent().getStringExtra("latitud").replace("Latitud:", ""));
tvDestinoLongitud.setText("Longitud:" + getIntent().getStringExtra("longitud").replace("Longitud:", ""));
tvOrigen.setText("Origen:" + mUbicacionActual);
tvDistancia.setText("Distancia:"+mDistancia);
tvTiempo.setText("Tiempo:" + mDuration);
}
}
}
I've tried out .executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR) but the app crashes. I've tried out also with a handler but it shows the same Behaviour, the first time takes 30 seconds or so, while the subsequents takes only a few.
Edit to show to points where i added log:
if (mCount==0) {
FillVariablesAsyncTask tareaAsincrona = new FillVariablesAsyncTask();
mStart=System.currentTimeMillis();
Log.i("START_BEFORE_EXECUTE", mStart + "");
tareaAsincrona.execute(origen, destino);
long end=System.currentTimeMillis();
Log.i("ELAPSED_EXECUTE", ((end-mStart)/1000) + "");
mCount++;
}
Here :
protected Document doInBackground(LatLng... params) {
long end;
end =System.currentTimeMillis();
Log.i("ELAPSE_PRE_BACKGROUND",((end- mStart)/1000)+"");
md=new GMapV2Direction();
end=System.currentTimeMillis();
Log.i("ELAPSED_POS_GMAPV2DIR",((end- mStart)/1000)+"");
LatLng origen=new LatLng(params[0].latitude,params[0].longitude);
LatLng destino=new LatLng(params[1].latitude,params[1].longitude);
end=System.currentTimeMillis();
Log.i("ELAPSED_PRE_GETDOCUMENT",((end- mStart)/1000)+"");
Document doc = md.getDocument(origen, destino, GMapV2Direction.MODE_WALKING);
end=System.currentTimeMillis();
Log.i("ELAPSED_POS_BACKGROUND",((end- mStart)/1000)+"");
/*mUbicacionActual = md.getStartAddress(doc);
mDuration=md.getDurationText(doc);
mDistancia=md.getDistanceText(doc);*/
return doc;
}
and here:
long end=System.currentTimeMillis();
Log.i("ELAPSED_onPostExecute",((end-mStart)/1000)+"");
mUbicacionActual = md.getStartAddress(doc);
mDuration=md.getDurationText(doc);
mDistancia=md.getDistanceText(doc);
end=System.currentTimeMillis();
Log.i("ELAPSED_POST_FILLVARS",((end-mStart)/1000)+"");
if (mUbicacionActual!=null && mDistancia!=null && mDuration!=null) {
progressBar.setVisibility(View.GONE);
btnIr.setEnabled(true);
tvOrigenLatitud.setText("Latitud:" + String.valueOf(mlastLocation.getLatitude()));
tvOrigenLongitud.setText("Longitud" + String.valueOf(mlastLocation.getLongitude()));
tvDestino.setText("Destino:" + getIntent().getStringExtra("info").replace("Info:", ""));
tvDestinoLatitud.setText("Latitud:" + getIntent().getStringExtra("latitud").replace("Latitud:", ""));
tvDestinoLongitud.setText("Longitud:" + getIntent().getStringExtra("longitud").replace("Longitud:", ""));
tvOrigen.setText("Origen:" + mUbicacionActual);
tvDistancia.setText("Distancia:"+mDistancia);
tvTiempo.setText("Tiempo:" + mDuration);
end=System.currentTimeMillis();
Log.i("ELAPSED_POS_onPostExecute", ((end - mStart) / 1000) + "");
}
this image shows the log output, it shows 3 but in reality is 30 or more.
[IMG]http://i61.tinypic.com/95o1ef.png[/IMG]

The time is taking have absolutely nothing to do with AsyncTask or Thread or Handler or Executor
The issue is that library you're using really takes that long to make calls to a server, or to process the information and I don't believe there's much you can do about it. It's only the 1st time because I'm guessing the library caches the result, but it still have nothing to do with the threading model you use.
The main point of my answer is that you're asking the wrong question. The correct question is:
Why this library is taking that long to process and what can you do to shorten it?
Unfortunately the only possible way to answer it is by analysing the source code of it or talking directly with the library developer.
edit:
to help you measure the executions:
public static class TimeMeasure {
private final DecimalFormat format;
private final double start;
private final String tag;
public TimeMeasure(String tag) {
this.format = new DecimalFormat("0.0");
this.start = System.currentTimeMillis();
this.tag = tag;
log("start);
}
public void log(String message) {
double elapsed = ((double) (System.currentTimeMillis() - start)) / 1000.0;
Log.d(tag, format.format(elapsed) + ": " + message);
}
}
then during doInBackground
protected Document doInBackground(LatLng... params) {
TimeMeasure tm = new TimeMeasure("Carlos");
// execute something:
tm.log("action 1");
// execute next
tm.log("action 2);
// etc...
}

I can't comment yet so here you go: you can use your IDE's debugger after you place breakpoints on every line in the two given blocks of code to see which line takes the most to execute. Then post your findings.

As the above answer mentioned it is actually the library that takes too much time.
I had a similar problem a while ago, I remember that after debugging what causes the problem was distance and duration and also if you were getting some kind of an address, it will contribute to the delay
(For Example) getting street name, city name and country etc..
I didn't really find any better API or library to deal with this but what i did was something to improve the user experience:
1-start another AsyncTask from onPostExecute() that will get duration and distance.
2- while the app is getting duration and distance don't block the user interface with a progress dialog or progress bar, just put loading... as an default value of your TextView then when the app receives the data setText to the actual value.
3-Do all of you data manipulation later after setting important data.
Hope this will help.

how to call Aysnctask in android

I am writing an android application, I use Aysnctask to get the current weather using openWeatherAPI. How could I call the Aysnctask class.
this is the Aysnctask class I wrote:
private class getWeather extends AsyncTask<String[], Void, String[]>{
#Override
protected String[] doInBackground(String[]... params) {
// TODO Auto-generated method stub
try {
String Url1="http://api.openweathermap.org/data/2.5/weather?lat="+currentLatitude+"&lon="+currentLongitude;
s1=getJson(Url1);
if(s1!=null){
JSONObject jObj1 = new JSONObject(s1);
Tem= jObj1.getJSONObject("main").getDouble("temp");
pressure=jObj1.getJSONObject("main").getDouble("pressure");
humm=jObj1.getJSONObject("main").getDouble("humidity");
wind=jObj1.getJSONObject("wind").getDouble("speed");
desc=jObj1.getJSONObject("weather").getDouble("description");
double tem_c=Tem-273.15;
String t=Double.toString(tem_c);
results[0]=t;
results[1]=Double.toString(pressure);
results[2]=Double.toString(humm);
results[3]=Double.toString(wind);
results[4]=Double.toString(desc);
}
} catch (Exception e) {
// TODO: handle exception
}
return results;
}//do in background
#Override
protected void onPostExecute(String[] results) {
temp.setText(results[0]+"°C");
hum.setText(results[1]+ "%");
press.setText(results[2]+ " hPa");
windSpeed.setText(results[3]+ " mps");
condDescr.setText(results[4]);
}
}
when I press a button, I want to get the weather of current latitude and longitude, but I don't know how to execute the class

try this
getWeather gt= new getWeather();
gt.execute(new String{currentLatitude,currentLongitude});

Per the android docs here, which have plenty of examples, you would do:
new GetWeather().execute(currentLatitude,currentLongitude);
I would personally shy away from holding a reference to it but rather send in what you need or use a listener. Also, please capitalize you classes :)
You access both of them like so in doInBackGround
String latitutde= params[0];
String longitude = params[1];
An example on the docs which you can look at is:
new DownloadFilesTask().execute(url1, url2, url3);
As you can see, pass however many parameters you need and it'll just be accessible in the array from the first generic parameter you mention. In your case its a String array, so you'd send only Strings.

Try this..
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
new getWeather(currentLatitude,currentLongitude).executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, new String[]{null});
else
new getWeather(currentLatitude,currentLongitude).execute(new String[]{null});
and also add constructor to your async task
String currentLatitude;
String currentLongitude;
// constructor
#SuppressWarnings("rawtypes")
public getWeather(String currentLatitude, String currentLongitude) {
this.currentLatitude = currentLatitude;
this.currentLongitude = currentLongitude;
}
EDIT 1:
You cannot parse double to string like this String t=Double.toString(tem_c);
you need to parse like below codes.
String t = String.valueOf(tem_c);
results[0] = t;
results[1] = String.valueOf(pressure);
results[2] = String.valueOf(humm);
results[3] = String.valueOf(wind);
results[4] = String.valueOf(desc);

Getting location data on an Android device in certain intervals

I am trying to make an Android app which takes the location data in certain intervals e.g:- 5 sec, 1 min,etc. Here is my code :-
public void onLocationChanged(Location loc) {
// TODO Auto-generated method stub
if(loc!=null)
{
//Required Interval
tInterval =(minInterval*60*1000) + (secInterval)*1000 - 1000;
//The app also supports interval mode
RadioButton sel = (RadioButton) findViewById(mode.getCheckedRadioButtonId());
//Code for Manual Functionality
if(sel.getText().equals(MANUAL_RADIO))
{
Time t = new Time();
t.setToNow();
db.addLocationAtTime(loc, t);
Toast.makeText(getApplicationContext(), "Location Added to Database",Toast.LENGTH_SHORT).show();
locate.removeUpdates(this);
b.setText(MANUAL_BUTTON);
d.setEnabled(true);
}
//Code for Interval functionality
else if(sel.getText().equals(INTERVAL_RADIO))
{
//count is object of Countdown class which is a Thread object
if(count == null)
{
//t is a Time object
t.setToNow();
//SQLiteDatabase object for logging Location with Time
db.addLocationAtTime(loc, t);
Toast.makeText(getApplicationContext(), "Location Added to Database",Toast.LENGTH_SHORT).show();
count = new CountDown( tInterval);
count.start();
}
else if(count.getState().toString().equals("TERMINATED"))
{
t.setToNow();
db.addLocationAtTime(loc, t);
Toast.makeText(getApplicationContext(), "Location Added to Database",Toast.LENGTH_SHORT).show();
count = new CountDown(tInterval);
count.start();
}
}
}
}
Here is the code for the Countdown class:-
This class is used to add the interval to the app
public class CountDown extends Thread
{
long time;
public CountDown(long duration)
{
time = duration;
}
public void run()
{
long t1 = System.currentTimeMillis();
long t2 = 0;
do
{
t2 = System.currentTimeMillis();
}while(t2 - t1 < time);
}
}
The problem is that using the above code I am not getting accurate intervals. I am always getting 1 sec extra (due to which I subtracted 1000 in the formula) , but this 1 sec is not happening always. So can anyone please tell me what I am doing wrong ?

Look at LocationManager.requestLocationUpdates, just pass your time interval in parameter..
LocationManager mLocationManager = (LocationManager).getSystemService(mActivity.LOCATION_SERVICE);
mLocationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 5000, 0, new GeoUpdateHandler());

i think here you need to use default features , no need to use Timer
NETWORK_PROVIDER
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 3000, 0, networkLocationListener);
GPS_PROVIDER
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 3000, 0, gpsLocationListener);
Here ,
minTime(2nd field) => minimum time interval between location updates, in milliseconds
minDistance(3rd field) => minimum distance between location updates, in meters
Documentation

I don't think the minTime param of the requestLocationUpdates(...) methods does anything at all. It does not seem to prevent distance-based updates from coming at shorter intervals, and it definitely does not cause updates to come at the specified interval, as many people seem to think. I've tried it on devices from Android 2.3.6 to 4.0.4.

For Loop reading infinity

I am trying to make a simple screen that shows you the amount of money you have earned by the second, so im trying to create a live feed type textveiw that updates every second with the amount of money you have earned, with my code when it runs on my phone it only reads "infinity" and when i tried to add in a 1 second delay it froze all together, here is the code that i wrote, i am using a for loop because i didnt know of a better way if anyone has a better way of achieving what i am trying to do please let me know..
// Calculate pay per second
double PPS = (HW/3600);
double OTPPS = (OTW/3600);
double HPDPS = (HPD*3600);
double money = 0;
double Reserve = 0;
loc = 0;
// Display
for(int i=0; i<HPDPS & loc!=7; i++)
{
money = (PPS+Reserve);
Reserve = (Reserve+money);
TextView textView = (TextView) this.findViewById(R.id.yourpay);
textView.setText(String.valueOf(money));
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
Thanks in advance for any help!
======================================================================================
Here is an edited version but i am still having a problem where it just displays infinity on the screen, how do i fix this? or how do i use the timer method?
public void sendMessage(View view) {
// Receive messages from options page
Intent intent = getIntent();
double HW = intent.getDoubleExtra(Options.MESSAGE_HW, 0);
double OTW = intent.getDoubleExtra(Options.MESSAGE_OTW, 0);
double HPD = intent.getDoubleExtra(Options.MESSAGE_HPD, 0);
// Calculate pay per second
double PPS = (HW/3600);
double OTPPS = (OTW/3600);
double HPDPS = (HPD*3600);
double money = 0;
double Reserve = 0;
// Display
for(int i=0; i<HPDPS; i++)
{
money = (PPS+Reserve);
Reserve = (Reserve+money);
TextView textView = (TextView) this.findViewById(R.id.yourpay);
textView.setText(String.valueOf(money));
}
// set textView
}

Better way is to user a Timer and TimerTask.
EDIT:
Here is a sample application code to user Timer and TimerTask:
final TextView t1 = (TextView) findViewById(R.id.textView1);
final Timer t =new Timer();
t.schedule(new TimerTask() {
#Override
public void run() {
runOnUiThread(new Runnable() {
#Override
public void run() {
t1.setText("Hello" + counter++); //Place your text data here
//Place your stopping condition over here. Its important to have a stopping condition or it will go in an infinite loop.
if(counter == 10)
t.cancel();
}
});
}
}, 1000, 1000);
Hope this helps.

[1] You are doing Bitwise ANDing (Bitwise ANDing -> &) here
for(int i=0; i<HPDPS & loc!=7; i++)
^
[2] Your loc in always 0, because you did loc=0 and in for loop loc is never updated
So loc!=7 is ALWAYS TRUE

GPS - Getting the distance,time while running and walking

i have a situation where i need to use GPS technique.
i need to find the distance between two points when the person is walking.
When the person starts walking he will click on Start button and when he stops he clicks on stop button
after this it should show him
1.time taken
2.Distance travelled in Kms.
3.from where to where(places name) eg: a to b
Do i need to have google maps for this?
I saw the code here link to get the current location which gives me latitude longitude.
please help how to go with this
**
Edited:
**
This is the code i am using
private EditText editTextShowLocation;
private Button buttonGetLocation;
private ProgressBar progress;
private LocationManager locManager;
private LocationListener locListener = new MyLocationListener();
private boolean gps_enabled = false;
private boolean network_enabled = false;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
editTextShowLocation = (EditText) findViewById(R.id.editTextShowLocation);
progress = (ProgressBar) findViewById(R.id.progressBar1);
progress.setVisibility(View.GONE);
buttonGetLocation = (Button) findViewById(R.id.buttonGetLocation);
buttonGetLocation.setOnClickListener(this);
locManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
}
#Override
public void onClick(View v) {
progress.setVisibility(View.VISIBLE);
// exceptions will be thrown if provider is not permitted.
try {
gps_enabled = locManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
} catch (Exception ex) {
}
try {
network_enabled = locManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
} catch (Exception ex) {
}
// don't start listeners if no provider is enabled
if (!gps_enabled && !network_enabled) {
AlertDialog.Builder builder = new Builder(this);
builder.setTitle("Attention!");
builder.setMessage("Sorry, location is not determined. Please enable location providers");
builder.setPositiveButton("OK", this);
builder.setNeutralButton("Cancel", this);
builder.create().show();
progress.setVisibility(View.GONE);
}
if (gps_enabled) {
locManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locListener);
}
if (network_enabled) {
locManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, locListener);
}
}
class MyLocationListener implements LocationListener {
#Override
public void onLocationChanged(Location location) {
if (location != null) {
// This needs to stop getting the location data and save the battery power.
locManager.removeUpdates(locListener);
String londitude = "Londitude: " + location.getLongitude();
String latitude = "Latitude: " + location.getLatitude();
String altitiude = "Altitiude: " + location.getAltitude();
String accuracy = "Accuracy: " + location.getAccuracy();
String time = "Time: " + location.getTime();
editTextShowLocation.setText(londitude + "\n" + latitude + "\n" + altitiude + "\n" + accuracy + "\n" + time);
progress.setVisibility(View.GONE);
}
}
#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
}
}
#Override
public void onClick(DialogInterface dialog, int which) {
if(which == DialogInterface.BUTTON_NEUTRAL){
editTextShowLocation.setText("Sorry, location is not determined. To fix this please enable location providers");
}else if (which == DialogInterface.BUTTON_POSITIVE) {
startActivity(new Intent(android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS));
}
}
It is showing the Logitude Latitude which i am entering from emulator control.
In this i am manually entering the details of longitude and latitude
by going to window->showview->other->emulator control for testing in the emulator
but what i need is i will have two edittext where i enter the place name(A) and (B)
it should give me the distance
please help

try using Google Distance Matrix Api
https://developers.google.com/maps/documentation/distancematrix/

You can use currentTimeinMillis() to get your start and end time for your journey.
You can then use the formulas explained here to find the distance and lastly you will have to use a reverse geocoding service such as Nominatim to be able to get the address of a place from your GPS coordinates.
That being said, the distance formula will get you the distance between one point and the next, not the actual displacement. If this is not what you need, but rather you want the actual distance travelled you will need to calculate this value at a shorter interval.

You can find out the distance between two locations(in terms of latitude and longitude) by making use of Spherical Trigonometry
Coming to time make use of simple date objects and compare the startTime and endTime.
(OR)
You can get approximate distance using below code
double distance;
Location locationA = new Location("point A");
locationA.setLatitude(latA);
locationA.setLongitude(lngA);
Location locationB = new Location("point B");
locationB.setLatitude(latB);
LocationB.setLongitude(lngB);
distance = locationA.distanceTo(locationB);

For getting the distance between 2points(A to B) there is a function called distanceTo in android.
For e.g.
double distance = startLocation.distanceTo(finishLocation)/1000;
For time taken as npinti said you can use currentTimeinMillis() or you can also use Timer and show it to user when he clicks on start button. Its just like stopwatch.
Edited
Place A - New York
Place B - Paris
In this case you first need to convert the string into Location(i.e you need latitude & longitude). For that you have use the concept of Geocoding.
List<Address> foundGeocode = null;
foundGeocode = new Geocoder(this).getFromLocationName("address here", 1);
foundGeocode.get(0).getLatitude(); //getting latitude
foundGeocode.get(0).getLongitude();//getting longitude
After that you can calculate the distance from the distanceTo method.
Hope this will help....

I suppose the question is one of walking..
Are you walking on the streets, or as the crow flies?
If it's streets, and your connected to the net, use google's api.. It calculates routing based on two points and returns XML.. Should be easy enough to figure out.
If it's crow flies.. well then, just do (a*a) + (b*b) = (c*c) this is by far the easier..
You could have your user tap for major turns.. Or you could keep a runnable running every 10 seconds from when they hit start, and plot the points. Still a*a+b*b=c*c but just a bunch of steps.
Of course you'd have to run it in a service.. And given the choice I'd go with that option. You could adjust the cycle time based on speed traveled. Faster would be smaller pauses.
It requires less on your dataplan.
EDIT
Ah.. I see what you're looking for. Tis not what I thought you were asking for.
Simplify.. convert lat/long to GPS. and then do simple math on the last point stored
void addDistance()
{
newX = ...
newY = ...
deltaX = absolute(m_oldX - newX)
deltaY = absolute(m_oldY = newY)
m_distance += sqrt(deltaX^2 + deltaY^2);
m_oldX = newX;
m_oldY = newY;
}
void startOver()
{
newX = ...
newY = ...
m_distance = 0;
m_oldX = newX;
m_oldY = newY;
}