'NullPointerException error on an Android-GeoFire project
This is the error I'm getting: java.lang. Attempt to call the virtual method 'double android.location.Location.getLatitude()' on a null object reference results in a NullPointerException.Can anyone guide me on how to achieve this?
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback,
GoogleApiClient.ConnectionCallbacks ,
GoogleApiClient.OnConnectionFailedListener,
LocationListener {
private GoogleMap mMap;
private ActivityMapsBinding binding;
private static final int MY_PERMISSION_REQUEST_CODE =71922 ;
private static final int PLAY_SERVICES_RESOLUTION_REQUEST = 300193;
private LocationRequest locationRequest;
private GoogleApiClient googleApiClient;
private Location mLastLocation ;
private static int UPDATE_INTERVAL =5000;
private static int FARTEST_INTERVAL =5000;
private static int DISPLACEMENT =10;
Marker marker;
DatabaseReference ref ;
GeoFire geoFire;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
binding = ActivityMapsBinding.inflate(getLayoutInflater());
setContentView(binding.getRoot());
// Obtain the SupportMapFragment and get notified when the map is ready to be used.
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
ref = FirebaseDatabase.getInstance().getReference("Test");
setupLocation();
}
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode)
{
case MY_PERMISSION_REQUEST_CODE:
if(grantResults.length>0 && grantResults[0] == PackageManager.PERMISSION_GRANTED)
{
if(checkPlayServices())
{
buildGoogleApiCLient();
createLocationRequest();
displayLocation();
}
}
break;
}
}
private void setupLocation() {
try {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION)
!= PackageManager.PERMISSION_GRANTED && ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED )
{
ActivityCompat.requestPermissions(this, new String[]{
Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.ACCESS_FINE_LOCATION
}, MY_PERMISSION_REQUEST_CODE);
}
else {
if(checkPlayServices())
{
buildGoogleApiCLient();
createLocationRequest();
displayLocation();
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
private void displayLocation() {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION)
!= PackageManager.PERMISSION_GRANTED && ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED )
{
return;
}
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(googleApiClient);
if(mLastLocation != null)
{
double latitude = mLastLocation.getLatitude();
double longitude = mLastLocation.getLongitude();
Log.d("EDMDEV",String.format("your location was changed: %f %f ",latitude,longitude));
// upDate to firebase
geoFire.setLocation("You", new GeoLocation(latitude, longitude), new GeoFire.CompletionListener() {
@Override
public void onComplete(String key, DatabaseError error) {
if(marker != null){
marker.remove(); //remove old marker
marker = mMap.addMarker(new MarkerOptions()
.position(new LatLng(latitude,longitude))
.title("Ele"));
mMap.animateCamera(CameraUpdateFactory.newLatLngZoom(new LatLng(latitude,longitude),12.0f));
}
}
});
}
else {
Log.d("EDMDEV","cannot get ur location");
}
}
private void createLocationRequest() {
locationRequest = new LocationRequest();
locationRequest.setInterval(UPDATE_INTERVAL);
locationRequest.setFastestInterval(FARTEST_INTERVAL);
locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}
private void buildGoogleApiCLient() {
googleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
googleApiClient.connect();
}
private boolean checkPlayServices() {
int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (resultCode != ConnectionResult.SUCCESS)
{
if(GooglePlayServicesUtil.isUserRecoverableError(resultCode))
GooglePlayServicesUtil.getErrorDialog(resultCode,this,PLAY_SERVICES_RESOLUTION_REQUEST).show();
else {
Toast.makeText(this, "this device is not support", Toast.LENGTH_SHORT).show();
finish();
}
return false ;
}
return true;
}
/**
* Manipulates the map once available.
* This callback is triggered when the map is ready to be used.
* This is where we can add markers or lines, add listeners or move the camera. In this case,
* we just add a marker near Sydney, Australia.
* If Google Play services is not installed on the device, the user will be prompted to install
* it inside the SupportMapFragment. This method will only be triggered once the user has
* installed Google Play services and returned to the app.
*/
@Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
// LatLng syd = new LatLng( -34,151);
// mMap.addMarker(new MarkerOptions().position(syd).title("mar in syd"));
// mMap.moveCamera(CameraUpdateFactory.newLatLng(syd));
//Create area
LatLng village = new LatLng(35.7533,-122.4056);
mMap.addCircle(new CircleOptions()
.center(village)
.radius(500) // in meter
.strokeColor(Color.BLUE)
.fillColor(0x220000FF)
.strokeWidth(5.0f)
);
// 0.5f = 0.5km = 500 m
GeoQuery geoQuery = geoFire .queryAtLocation(new GeoLocation(village.latitude,village.longitude),0.5f);
geoQuery.addGeoQueryEventListener(new GeoQueryEventListener() {
@Override
public void onKeyEntered(String key, GeoLocation location) {
sendNotification("EDKDD",String.format("%s entered village area ",key ));
}
@Override
public void onKeyExited(String key) {
sendNotification("EDKDD",String.format("%s no longer village area ",key ));
}
@Override
public void onKeyMoved(String key, GeoLocation location) {
sendNotification("Move",String.format("%s moved within the village area [%f/%f]",key,location.latitude, location.longitude ));
}
@Override
public void onGeoQueryReady() {
}
@Override
public void onGeoQueryError(DatabaseError error) {
Log.e("Error","" + error);// 36.46
}
});
}
private void sendNotification(String title, String content) {
Notification.Builder builder = new Notification.Builder(this)
.setSmallIcon(R.mipmap.ic_launcher_round)
.setContentTitle(title)
.setContentText(content);
NotificationManager notificationManager = (NotificationManager) this.getSystemService(Context.NOTIFICATION_SERVICE);
Intent intent = new Intent(this,MapsActivity.class);
PendingIntent contentIntent = PendingIntent.getActivity(this,0,intent,PendingIntent.FLAG_IMMUTABLE);
builder.setContentIntent(contentIntent);
Notification notification = builder.build();
notification.flags = Notification.DEFAULT_SOUND;
notificationManager.notify(new Random().nextInt(),notification);
}
@Override
public void onConnected(@Nullable Bundle bundle) {
displayLocation();
startLocationUpdate();
}
private void startLocationUpdate() {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION)
!= PackageManager.PERMISSION_GRANTED && ContextCompat.checkSelfPermission(this, android.Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED )
{
return;
}
LocationServices.FusedLocationApi.requestLocationUpdates(googleApiClient,locationRequest,this);
}
@Override
public void onConnectionSuspended(int i) {
}
@Override
public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
}
@Override
public void onLocationChanged(Location location) {
mLastLocation = location;
displayLocation();
}
}
java.lang.NullPointerException Error
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.newapp.elephantapplication, PID: 3267
java.lang.NullPointerException: Attempt to invoke virtual method 'com.firebase.geofire.GeoQuery com.firebase.geofire.GeoFire.queryAtLocation(com.firebase.geofire.GeoLocation, double)' on a null object reference
at com.newapp.elephantapplication.MapsActivity.onMapReady(MapsActivity.java:224)
at com.google.android.gms.maps.zzat.zzb(com.google.android.gms:play-services-maps@@18.0.0:1)
at com.google.android.gms.maps.internal.zzaq.zza(com.google.android.gms:play-services-maps@@18.0.0:5)
at com.google.android.gms.internal.maps.zzb.onTransact(com.google.android.gms:play-services-maps@@18.0.0:3)
at android.os.Binder.transact(Binder.java:387)
at eg.aZ(:com.google.android.gms.dynamite_mapsdynamite@[email protected] (040308-0):2)
at com.google.maps.api.android.lib6.impl.bk.run(:com.google.android.gms.dynamite_mapsdynamite@[email protected] (040308-0):1)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:158)
at android.app.ActivityThread.main(ActivityThread.java:7224)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
Just getting used to Java and Android and I've got the above error. Can anyone guide me on how to achieve this?
Sources
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Source: Stack Overflow
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