I can not get data from the OpenWeatherMap API When I use the GPS Coordinates As Argument

I'm trying to make a small application that consumes the OpenWeatherMap API but uses the location of the device to do so, the coordinates.

I was able to get the coordinates of the device, however when I injected the same coordinates in the URL to make the call to the service it does not return information, as if no coordinates had been entered in its parameters.

Can you help me?

Below is the code I've created so far:

<code="java">public class MainActivity extends AppCompatActivity {

    private LocationManager locationManager;
    private LocationListener listener;

    static float lat;
    static float lon;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction().add(R.id.container, new WeatherFragment()).commit();
        }


        locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);


        listener = new LocationListener() {
            @Override
            public void onLocationChanged(Location location) {
                lat = (float)location.getLatitude();
                lon = (float)location.getLongitude();

                //t.setText("\n " + lat + "\n" + lon);
            }

            @Override
            public void onStatusChanged(String s, int i, Bundle bundle) {

            }

            @Override
            public void onProviderEnabled(String s) {

            }

            @Override
            public void onProviderDisabled(String s) {

                Intent i = new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
                startActivity(i);
            }
        };

        configure_button();


    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.weather, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if(item.getItemId() == R.id.change_city){
            showInputDialog();
        }
        return false;
    }

    private void showInputDialog(){
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Escolher a Cidade:");
        final EditText input = new EditText(this);
        input.setInputType(InputType.TYPE_CLASS_TEXT);
        builder.setView(input);
        builder.setPositiveButton("Go", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                changeCity(input.getText().toString());
            }
        });
        builder.show();
    }

    public void changeCity(String city){
        WeatherFragment wf = (WeatherFragment)getSupportFragmentManager()
                .findFragmentById(R.id.container);
        wf.changeCity(city);
        new CityPreference(this).setCity(city);
    }


    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode){
            case 10:
                configure_button();
                break;
            default:
                break;
        }
    }

    void configure_button(){
        // first check for permissions
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                requestPermissions(new String[]{Manifest.permission.ACCESS_COARSE_LOCATION,Manifest.permission.ACCESS_FINE_LOCATION,Manifest.permission.INTERNET}
                        ,10);
            }
            return;
        }
        // this code won't execute IF permissions are not allowed, because in the line above there is return statement.

        //noinspection MissingPermission
        locationManager.requestLocationUpdates("gps", 5000, 0, listener);
    }

}</code>

RemoteFetch.java

<code>public class RemoteFetch extends MainActivity{    

    //private static final String OPEN_WEATHER_MAP_API = "http://api.openweathermap.org/data/2.5/weather?q=%s&units=metric";    

    //private static final String OPEN_WEATHER_MAP_API = "http://api.openweathermap.org/data/2.5/weather?lat=35&lon=139&units=metric";

    private static final String OPEN_WEATHER_MAP_API = "http://api.openweathermap.org/data/2.5/weather?lat=" + lat + "&lon=" + lon + "&units=metric";     

    public static JSONObject getJSON(Context context, String city){
        try {
            URL url = new URL(String.format(OPEN_WEATHER_MAP_API, city));           
            HttpURLConnection connection = 
                    (HttpURLConnection)url.openConnection();

            connection.addRequestProperty("x-api-key", context.getString(R.string.open_weather_maps_app_id));

            BufferedReader reader = new BufferedReader(
                    new InputStreamReader(connection.getInputStream()));

            StringBuffer json = new StringBuffer(1024);
            String tmp="";
            while((tmp=reader.readLine())!=null)
                json.append(tmp).append("\n");
            reader.close();

            JSONObject data = new JSONObject(json.toString());

            if(data.getInt("cod") != 200){
                return null;
            }

            return data;
        }catch(Exception e){
            return null;
        }
    }

}</code>

WeatherFragment.java

<code>public class WeatherFragment extends Fragment {

    Typeface weatherFont;

    TextView cityField;
    TextView updatedField;
    TextView detailsField;
    TextView currentTemperatureField;
    TextView weatherIcon;

    TextView windField;

    Handler handler;

    public WeatherFragment(){   
        handler = new Handler();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_weather, container, false);
        cityField = (TextView)rootView.findViewById(R.id.city_field);
        updatedField = (TextView)rootView.findViewById(R.id.updated_field);
        detailsField = (TextView)rootView.findViewById(R.id.details_field);
        currentTemperatureField = (TextView)rootView.findViewById(R.id.current_temperature_field);
        weatherIcon = (TextView)rootView.findViewById(R.id.weather_icon);

        windField = (TextView)rootView.findViewById(R.id.wind_detail);

        weatherIcon.setTypeface(weatherFont);
        return rootView; 
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);  
        weatherFont = Typeface.createFromAsset(getActivity().getAssets(), "weather.ttf");
        updateWeatherData(new CityPreference(getActivity()).getCity());
    }

    private void updateWeatherData(final String city){
        new Thread(){
            public void run(){
                final JSONObject json = RemoteFetch.getJSON(getActivity(), city);
                if(json == null){
                    handler.post(new Runnable(){
                        public void run(){
                            Toast.makeText(getActivity(), 
                                    getActivity().getString(R.string.place_not_found), 
                                    Toast.LENGTH_LONG).show(); 
                        }
                    });
                } else {
                    handler.post(new Runnable(){
                        public void run(){
                            renderWeather(json);
                        }
                    });
                }               
            }
        }.start();
    }

    private void renderWeather(JSONObject json){
        try {
            cityField.setText(json.getString("name").toUpperCase(Locale.US) + 
                    ", " + 
                    json.getJSONObject("sys").getString("country"));

            JSONObject details = json.getJSONArray("weather").getJSONObject(0);
            JSONObject main = json.getJSONObject("main");
            detailsField.setText(
                    details.getString("description").toUpperCase(Locale.US) +
                    "\n" + "Humidity: " + main.getString("humidity") + "%" +
                    "\n" + "Pressure: " + main.getString("pressure") + " hPa");

            JSONObject wind = json.getJSONObject("wind");

            //converter para km/h
            double wind_ms = Double.parseDouble(wind.getString("speed").toUpperCase(Locale.getDefault()));
            double wind_km = wind_ms * 3.6;
            //DecimalFormat decimal = new DecimalFormat("#.##");
            //wind_km = Double.valueOf(decimal.format(wind_km));
            windField.setText("Wind: " + wind_km + " Km/h   ");


            currentTemperatureField.setText(
                        String.format("%.2f", main.getDouble("temp"))+ " ℃");

            DateFormat df = DateFormat.getDateTimeInstance();
            String updatedOn = df.format(new Date(json.getLong("dt")*1000));
            updatedField.setText("Last update: " + updatedOn);

            setWeatherIcon(details.getInt("id"),
                    json.getJSONObject("sys").getLong("sunrise") * 1000,
                    json.getJSONObject("sys").getLong("sunset") * 1000);

        }catch(Exception e){
            Log.e("SimpleWeather", "One or more fields not found in the JSON data");
        }
    }

    private void setWeatherIcon(int actualId, long sunrise, long sunset){
        int id = actualId / 100;
        String icon = "";
        if(actualId == 800){
            long currentTime = new Date().getTime();
            if(currentTime>=sunrise && currentTime<sunset) {
                icon = getActivity().getString(R.string.weather_sunny);
            } else {
                icon = getActivity().getString(R.string.weather_clear_night);
            }
        } else {
            switch(id) {
            case 2 : icon = getActivity().getString(R.string.weather_thunder);
                     break;         
            case 3 : icon = getActivity().getString(R.string.weather_drizzle);
                     break;     
            case 7 : icon = getActivity().getString(R.string.weather_foggy);
                     break;
            case 8 : icon = getActivity().getString(R.string.weather_cloudy);
                     break;
            case 6 : icon = getActivity().getString(R.string.weather_snowy);
                     break;
            case 5 : icon = getActivity().getString(R.string.weather_rainy);
                     break;
            }
        }
        weatherIcon.setText(icon);
    }

    public void changeCity(String city){
        updateWeatherData(city);
    }
}</code>

Running this code the result I have is the following:

However, if I manually inject a valid coordinate, I get its response from the service, so I foresee that the problem is getting the coordinates of the device and injecting it on time into the service URL.