Develop Reference

Cannot resolve symbol "locationListener" - Android

I am having trouble implementing a LocationListener.
import androidx.appcompat.app.AppCompatActivity;
import android.Manifest;
import android.content.Context;
import android.content.pm.PackageManager;
import android.location.Address;
import android.location.Criteria;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.TextView;
import java.io.IOException;
import java.util.List;
import java.util.Locale;
public class MainActivity extends AppCompatActivity {
TextView latitudeTV;
TextView longitudeTV;
TextView altitudeTV;
TextView locationNameTV;
double latitude;
double longitude;
double altitude;
String locationName;
LocationManager locationManager;
Location location;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
latitudeTV = (TextView) findViewById(R.id.latitude);
longitudeTV = (TextView) findViewById(R.id.longitude);
altitudeTV = (TextView) findViewById(R.id.altitude);
locationNameTV = (TextView) findViewById(R.id.locationName);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5000, 0, locationListener);
location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
onLocationChanged(location);
LocationListener locationListener = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
longitude = location.getLongitude();
latitude = location.getLatitude();
altitude = location.getAltitude();
locationName = "Placeholder";
longitudeTV.setText("Longitude: \n" + longitude + "°");
latitudeTV.setText("Latitude: \n" + latitude + "°");
altitudeTV.setText("Altitude: \n" + altitude + "m");
locationNameTV.setText("Location: \n" + locationName);
}
#Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
#Override
public void onProviderEnabled(String s) {
}
#Override
public void onProviderDisabled(String s) {
}
};
}
}
I'm not sure if it's a syntax issue or a scoping issue, but I keep getting "unable to resolve symbol" errors. It's acting like I haven't implemented the LocationListener methods. I have tried adding implements LocationListener to MainActivity and that shows an error saying I have not implemented the LocationListener methods. I'm not sure where my mistake is.
EDIT:
I've changed my code per your answers. When I try to implement //locationManager.requestLocationUpdates(Context.LOCATION_SERVICE, 5000, 0, this); I get the following when trying to launch the app: LocationTestApp keeps stopping. I've commented out that line, and the app works again.
public class MainActivity extends AppCompatActivity implements LocationListener {
TextView latitudeTV;
TextView longitudeTV;
TextView altitudeTV;
double latitude;
double longitude;
double altitude;
LocationManager locationManager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
latitudeTV = (TextView) findViewById(R.id.latitude);
longitudeTV = (TextView) findViewById(R.id.longitude);
altitudeTV = (TextView) findViewById(R.id.altitude);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
//locationManager.requestLocationUpdates(Context.LOCATION_SERVICE, 5000, 0, this);
Location location = locationManager.getLastKnownLocation(locationManager.NETWORK_PROVIDER);
onLocationChanged(location);
}
#Override
public void onLocationChanged(Location location) {
longitude = location.getLongitude();
latitude = location.getLatitude();
altitude = location.getAltitude();
longitudeTV.setText("Longitude: \n" + longitude + "°");
latitudeTV.setText("Latitude: \n" + latitude + "°");
altitudeTV.setText("Altitude: \n" + altitude + "m");
}
#Override
public void onStatusChanged(String s, int i, Bundle bundle) {
}
#Override
public void onProviderEnabled(String s) {
}
#Override
public void onProviderDisabled(String s) {
}
}

A LocationListener class, in this case an Activity, should be defined as below:
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
public class MainActivity extends AppCompatActivity implements LocationListener {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
...
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5000, 0, this); // Note: You pass this, so the overridden methods
}
#Override
public void onLocationChanged(Location location) {
// Do your stuff here
}
#Override
public void onProviderDisabled(String provider) {}
#Override
public void onProviderEnabled(String provider) {}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {}
}
And this is the solution in jle's comments.
But if you want to use the locationListener that you've declared in your onCreate, you should declare it before using it, in this way:
...onCreate(...) {
...
LocationListener locationListener = new LocationListener() {...} // Define this...
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 5000, 0, locationListener); // ...and then call this
location = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
onLocationChanged(location);
}

How to get user Location in Android 4.4 or above when GPS is off

My Application crashes when gps is off and the back end code searches for the location of the user. I have tried the following code for finding the location of user when gps is off it searches using the internet.
Please suggest something in the following code or any other way
below is my code for the locationservice:
package com.example.myapp;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;
public class LocationService extends Service implements LocationListener {
protected LocationManager locationManager;
Location location;
private static final long MIN_DISTANCE_FOR_UPDATE = 10;
private static final long MIN_TIME_FOR_UPDATE = 1000 * 60 * 2;
public LocationService(Context context) {
locationManager = (LocationManager) context
.getSystemService(LOCATION_SERVICE);
}
public Location getLocation(String provider) {
if (locationManager.isProviderEnabled(provider)) {
locationManager.requestLocationUpdates(provider,
MIN_TIME_FOR_UPDATE, MIN_DISTANCE_FOR_UPDATE, this);
if (locationManager != null) {
location = locationManager.getLastKnownLocation(provider);
return location;
}
}
return null;
}
#Override
public void onLocationChanged(Location location) {
}
#Override
public void onProviderDisabled(String provider) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public IBinder onBind(Intent arg0) {
return null;
}
}

how to detect location in android very fastly

my android application can detect longitude and latitude. but it take some time. my app has 9 activates and last activity should send location to data base. any one can give a solution for this. i want to detect location soon as possible, what did missed in my code?
package com.example.zlocation;
import android.app.Activity;
import android.content.Context;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.util.Log;
import android.widget.TextView;
public class MainActivity extends Activity implements LocationListener{
protected LocationManager locationManager;
protected LocationListener locationListener;
protected Context context;
protected TextView txtLat;
String lat;
String provider;
protected String latitude,longitude;
protected boolean gps_enabled,network_enabled;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
txtLat = (TextView) findViewById(R.id.textView1);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
}
#Override
public void onLocationChanged(Location location) {
txtLat = (TextView) findViewById(R.id.textView1);
txtLat.setText("Latitude:" + location.getLatitude() + ", Longitude:" + location.getLongitude());
}
#Override
public void onProviderDisabled(String provider) {
Log.d("Latitude","disable");
}
#Override
public void onProviderEnabled(String provider) {
Log.d("Latitude","enable");
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
Log.d("Latitude","status");
}
}

You are trying to get the location from gps provider.The problem with gps is however vit is accurate but it takes time in starting the gps and providing a location it can take anything from 2-30 seconds to provide the location if you want location as soon as possible have a look at fused location provider by google and implement it in that you can define the time after you want the location updates or from my personal experience i would suggest you to have a look at littlefluffy location library it is easier to implement.

Cant get a location on Android smartphone

I am trying to get a location (latitude, longitude) on my Android smartphone (HTC Desire HD), using Wifi-network and GPS.
This is the code I use, only I keep getting "Location not available"
Iam working with Eclipse IDE.
import android.app.Activity;
import android.content.Context;
import android.location.Criteria;
import com.example.shortsproject.R;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.widget.TextView;
import android.widget.Toast;
public class LocationGetter extends Activity implements LocationListener {
private TextView latituteField;
private TextView longitudeField;
private LocationManager locationManager;
private String provider;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.location);
latituteField = (TextView) findViewById(R.id.locationtext);
longitudeField = (TextView) findViewById(R.id.locationtext2);
// Get the location manager
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
// Define the criteria how to select the location provider -> use
// default
Criteria criteria = new Criteria();
provider = locationManager.getBestProvider(criteria, false);
Location location = locationManager.getLastKnownLocation(provider);
// Initialize the location fields
if (location != null) {
System.out.println("Provider " + provider + " has been selected.");
onLocationChanged(location);
} else {
latituteField.setText("Location not available");
longitudeField.setText("Location not available");
}
}
/* Request updates at startup */
#Override
protected void onResume() {
super.onResume();
locationManager.requestLocationUpdates(provider, 400, 1, this);
}
/* Remove the locationlistener updates when Activity is paused */
#Override
protected void onPause() {
super.onPause();
locationManager.removeUpdates(this);
}
#Override
public void onLocationChanged(Location location) {
int lat = (int) (location.getLatitude());
int lng = (int) (location.getLongitude());
latituteField.setText(String.valueOf(lat));
longitudeField.setText(String.valueOf(lng));
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
#Override
public void onProviderEnabled(String provider) {
Toast.makeText(this, "Enabled new provider " + provider,
Toast.LENGTH_SHORT).show();
}
#Override
public void onProviderDisabled(String provider) {
Toast.makeText(this, "Disabled provider " + provider,
Toast.LENGTH_SHORT).show();
}
}
Can someone help me with this?

GPS not working

What I am doing is trying to get a basic GPS working and can't figure out the problem (there is no errors coming up). When i run it on the emulator it crashes. I am using android 2.2
package Weather.app;
import android.app.Activity;
import android.content.Context;
import android.location.Location;
import android.location.Geocoder;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;
public class WeatherAppActivity extends Activity{
/** Called when the activity is first created. */
private static final long MINIMUM_DISTANCE_CHANGE_FOR_UPDATES = 1; // in Meters
private static final long MINIMUM_TIME_BETWEEN_UPDATES = 1000; // in Milliseconds
protected LocationManager locationManager;
protected LocationListener MyLocationListener;
protected Button findButton;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
findButton = (Button) findViewById(R.id.findButton);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(
locationManager.GPS_PROVIDER,
MINIMUM_TIME_BETWEEN_UPDATES,
MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
(LocationListener) this
);
findButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
showCurrentLocation();
}
});
}
protected void showCurrentLocation() {
Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
if (location != null) {
String message = String.format(
"Current Location \n Longitude: %1$s \n Latitude: %2$s",
location.getLongitude(), location.getLatitude()
);
Toast.makeText(WeatherAppActivity.this, message,
Toast.LENGTH_LONG).show();
}
final class MyLocationListener implements LocationListener {
#Override
public void onLocationChanged(Location location) {
String message = String.format(
"New Location \n Longitude: %1$s \n Latitude: %2$s",
location.getLongitude(), location.getLatitude()
);
Toast.makeText(WeatherAppActivity.this, message, Toast.LENGTH_LONG).show();
}
#Override
public void onStatusChanged(String s, int i, Bundle b) {
Toast.makeText(WeatherAppActivity.this, "Provider status changed",
Toast.LENGTH_LONG).show();
}
#Override
public void onProviderDisabled(String s) {
Toast.makeText(WeatherAppActivity.this,
"Provider disabled by the user. GPS turned off",
Toast.LENGTH_LONG).show();
}
#Override
public void onProviderEnabled(String s) {
Toast.makeText(WeatherAppActivity.this,
"Provider enabled by the user. GPS turned on",
Toast.LENGTH_LONG).show();
}
}
}
}
This is also in my manifest:
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_LOCATION_EXTRA_COMMANDS" />
<uses-permission android:name="android.permission.CONTROL_LOCATION_UPDATES" />
I have updated this code as I have made a few changes

Here is one example of working basic GPS activity:
public class UseGpsActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
}
/* Class My Location Listener */
public class MyLocationListener implements LocationListener{
#Override
public void onLocationChanged(Location loc) {
// TODO Auto-generated method stub
double lati = loc.getLatitude();
double longi = loc.getLongitude();
String Text = "My current location is: " + "Latitud = " + lati + "Longitud = " + longi;
Toast.makeText(getApplicationContext(),Text,Toast.LENGTH_SHORT).show();
}
#Override
public void onProviderDisabled(String provider) {
// TODO Auto-generated method stub
Toast.makeText(getApplicationContext(),"Gps Disabled",Toast.LENGTH_SHORT).show();
}
#Override
public void onProviderEnabled(String provider) {
// TODO Auto-generated method stub
Toast.makeText(getApplicationContext(),"Gps Enabled",Toast.LENGTH_SHORT).show();
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
// TODO Auto-generated method stub
}
}
}

Unless some code is missing in your post MyLocationListener (you should not user upper case identifiers for instance fields!) is not initialized when passing the reference (i.e. null) to requestLocationUpdates().

You don't need to create another LocationListener, the statement
WeatherAppActivity extends Activity implements LocationListener
and the overriden methods
#Override
public void onLocationChanged(Location location)
etc means you have one in your main class already, so get rid of the inner class MyLocationListener completely.
Put your Toast code etc inside the overriden listener methods in the main class.
Then in onCreate() have :
locationManager.requestLocationUpdates(
locationManager.GPS_PROVIDER,
MINIMUM_TIME_BETWEEN_UPDATES,
MINIMUM_DISTANCE_CHANGE_FOR_UPDATES,
this
);

I have a tutorial on Android location services on my blog. I'm not sure of your specific error but you can look at the code to see if it helps you!
http://www.scotthelme.co.uk/blog/android-location-services/