Getting Lat and Long values from FusedLocationProviderClient android

Question

I am trying to use FusedLocationProviderClient to get the Latitude and Longitude of the current location. My code so far is as follows:

Manifest

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>

Layout: have a button

build.gradle

implementation 'com.google.android.gms:play-services-location:16.0.0'

Java

ArrayList<String> Coord_Array;

Inside OnCreate method

private FusedLocationProviderClient client;
client = LocationServices.getFusedLocationProviderClient( ShowOutletParams.this );
Coord_Array = new ArrayList<String>();

Outside OnCreate method - I am using getLocation() inside the button onclicklistener

private String getLocation() {
        if (ActivityCompat.checkSelfPermission( ShowOutletParams.this, Manifest.permission.ACCESS_FINE_LOCATION ) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission( ShowOutletParams.this, Manifest.permission.ACCESS_COARSE_LOCATION ) != PackageManager.PERMISSION_GRANTED) {
            return;
        }
        client.getLastLocation().addOnSuccessListener( ShowOutletParams.this, new OnSuccessListener<Location>() {
            @Override
            public void onSuccess(Location location) {
                if (location != null) {
                    String locat = location.toString();
                    String lat = locat.substring(15,24);
                    String longi = locat.substring(25,34);
                    Coord_Array.add(lat);
                    Coord_Array.add(longi);
                    //return Coord_Array;
                }
            }
        } );

    }

When I add Log.i to log the lat and long values, I could see them in the log, however I want them to be saved as strings, which I want to use later.
I understand void does not return anything....however the Coord_Array too doesn't return or print the lat and long.

score 1 · Accepted Answer · answered Apr 27 '19 at 06:49

You should try :

client.getLastLocation().addOnSuccessListener( ShowOutletParams.this, new OnSuccessListener<Location>() {
        @Override
        public void onSuccess(Location location) {
                    if (location != null) {
                        double mLatitude = location.getLatitude();
                        double mLongitude = location.getLongitude();                           
                    }
                });
            } else {
                Toast.makeText(this, "Permission denied", Toast.LENGTH_SHORT).show();
            }}

if still facing issue check for the tutorial

score 1 · Answer 2 · answered Apr 27 '19 at 15:03

The main problem is your method private String getLocation() returns before any Location is actually available (and I'm pretty sure it won't compile by looking at it).

When you're here:

if (ActivityCompat.checkSelfPermission( ShowOutletParams.this, Manifest.permission.ACCESS_FINE_LOCATION ) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission( ShowOutletParams.this, Manifest.permission.ACCESS_COARSE_LOCATION ) != PackageManager.PERMISSION_GRANTED) {
   return;
}

you're still in the standard flow of your method. But once you get passed here:

client.getLastLocation().addOnSuccessListener(

all of the code within your public void onSuccess(Location location) is now running AFTER your call to getLocation() has already returned!

A simple solution is to pass in callbacks into your getLocation() method, so that they can be triggered after the method has already returned to its caller, e.g.

public interface LocationAvailableListener {
    public void onLocationAvailable(Location location)
}

public void getLocation(LocationAvailableListener locationAvaialbleCallback, Runnable locationNotAvailableCallback) {
...

Then when checking permissions, you can now trigger your failure callback:

if (ActivityCompat.checkSelfPermission( ShowOutletParams.this, Manifest.permission.ACCESS_FINE_LOCATION ) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission( ShowOutletParams.this, Manifest.permission.ACCESS_COARSE_LOCATION ) != PackageManager.PERMISSION_GRANTED) {
   locationNotAvailableCallback.run();

   return;
}

and then in your onSuccess

if (location != null) {
   locationAvaialbleCallback.onLocationAvailable(location);
}
else {
   locationNotAvailableCallback.run();
}

And then to use:

getLocation(
   location -> {
      String latitude = String.valueOf(location.getLatitude());
      String longitude = String.valueOf(location.getLongitude());

      // Add to your ArrayList here
      // Save to your database or wherever for later
   },
   { Log.i(TAG, "Failed to get Location"); })

And since you asked about persisting the Location data once you have it, this reference should point you in the right direction with some simple JSON serialization.

Thank you....This is my first app....and have never built anything with Java....will try your suggestion. — Apricot, Apr 27 '19 at 15:38
Thank you for all the explanation....I clearly understand where I was going wrong.... — Apricot, Apr 27 '19 at 15:41

score 0 · Answer 3 · answered Apr 27 '19 at 05:55

0

You have to get Longitude and Latitude directly from the location object and cast it to string as you want.

in Kotlin :

lat = location.latitude.toString()

and in Java :

lat = location.getLatitude() + "";

answered Apr 27 '19 at 05:55

Shynline

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Getting Lat and Long values from FusedLocationProviderClient android

3 Answers3