How to retrieve multiple location which set by using Geofire from Real-time Firebase and show them on map in Android Studio?

Question

The aim of my application is to retrieve all users current location from real-time firebase and show it on the map in Android Studio. The location of the user is set by using GeoFire and stored in the real-time firebase. The code of setting GeoFire is as follow:

private void settingGeoFire() {
    String firebaseAuth = FirebaseAuth.getInstance().getUid();
    myLocationRef = FirebaseDatabase.getInstance().getReference("UserLocation/"+firebaseAuth);
    geoFire = new GeoFire(myLocationRef);
}

and the structure of the real-time firebase is as follow:

The question is how to retrieve all user's latitude and longitude which are stored under the file 0 and 1 (refer to the image above) in real-time firebase and show them as multiple markers on the map in android studio? Thanks if you can help!

Answer 1

To get the values of the latitude and longitude from the (0) and (1) nodes, please use the following lines of code:

DatabaseReference db = FirebaseDatabase.getInstance().getReference();
DatabaseReference userLocationRef = db.child("UserLocation");
userLocationRef.get().addOnCompleteListener(new OnCompleteListener<DataSnapshot>() {
    @Override
    public void onComplete(@NonNull Task<DataSnapshot> task) {
        if (task.isSuccessful()) {
            for (DataSnapshot ds : task.getResult().getChildren()) {
                doube lat = ds.child("You").child("l").child("0").getValue(Double.class);
                doube lng = ds.child("You").child("l").child("1").getValue(Double.class);
                Log.d("TAG", lat + ", " + lng); //Check the values

                //Add location on Google Map
                LatLng location = new LatLng(lat, lng);

                map.addMarker(new MarkerOptions()
                        .position(location)
                        .title(lat + ", " + lng)
                        .showInfoWindow();
            }
        } else {
            Log.d("TAG", task.getException().getMessage()); //Don't ignore potential errors!
        }
    }
});