I'm quite new to android development and I was wondering if it is possible for me to locate the nearest marker to a user and knowing which marker is closest direct the user there using a polyline and google directions api. The locations of the markers are taken from a database that I have parsed into a list array which I then use to place the markers on the map. I have tried to find help from other questions however they do not seem to fit in my project.
If it is possible for me to find the nearest marker to the user how can I do it if not is there an alternative method I could use??
This is my code for my main activity:
package com.example.defiblocator;
import android.Manifest;
import android.content.pm.PackageManager;
import android.location.Location;
import android.os.Build;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.content.ContextCompat;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.location.LocationListener;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class MainActivity extends AppCompatActivity implements OnMapReadyCallback,
LocationListener,GoogleApiClient.ConnectionCallbacks,
GoogleApiClient.OnConnectionFailedListener{
public static TextView data;
public static String location;
GoogleMap mapAPI;
SupportMapFragment mapFragment;
Location mLastLocation;
Marker mCurrLocationMarker;
GoogleApiClient mGoogleApiClient;
LocationRequest mLocationRequest;
String delimiter = ",";
List<String> full = new ArrayList<>();
List<String> size = new ArrayList<>();
private ArrayList<LatLng> markerCoords = new ArrayList<LatLng>();
String info;
String name;
Double lat;
Double lng;
Button emergency;
LatLng mark;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mapFragment = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.mapAPI);
mapFragment.getMapAsync(this);
data = findViewById(R.id.fetchdata);
new fetchData(new CallbackClass()).execute();
emergency = findViewById(R.id.button);
emergency.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
}
});
}
#Override
public void onMapReady(GoogleMap googleMap) {
mapAPI = googleMap;
mapAPI.getUiSettings().setZoomControlsEnabled(true);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
buildGoogleApiClient();
mapAPI.setMyLocationEnabled(true);
//mapAPI.setOnMyLocationChangeListener(this);
}
} else {
buildGoogleApiClient();
mapAPI.setMyLocationEnabled(true);
}
}
protected synchronized void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API).build();
mGoogleApiClient.connect();
}
#Override
public void onConnected(Bundle bundle) {
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(1000);
mLocationRequest.setFastestInterval(1000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_BALANCED_POWER_ACCURACY);
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION)
== PackageManager.PERMISSION_GRANTED) {
LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, mLocationRequest, this);
}
}
#Override
public void onConnectionSuspended(int i) {
}
#Override
public void onLocationChanged(Location location) {
/*mLastLocation = location;
if (mCurrLocationMarker != null) {
mCurrLocationMarker.remove();
}*/
//Place current location marker
LatLng patient = new LatLng(location.getLatitude(), location.getLongitude());
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.position(patient);
markerOptions.title("Patient");
markerOptions.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE));
mCurrLocationMarker = mapAPI.addMarker(markerOptions);
//move map camera
mapAPI.animateCamera(CameraUpdateFactory.zoomTo(11));
mapAPI.moveCamera(CameraUpdateFactory.newLatLng(patient));
//stop location updates
if (mGoogleApiClient != null) {
LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, this);
}
}
#Override
public void onConnectionFailed(#NonNull ConnectionResult connectionResult) {
}
public class CallbackClass implements CallbackInterface {
#Override
public void onSuccess(String callbackData) {
info = callbackData;
full = Arrays.asList(info.split(delimiter));
size = Arrays.asList(info.split(delimiter));
Integer x = 0;
while(x != size.size()){
name = full.get(x);
x += 1;
lat = Double.valueOf(full.get(x));
x += 1;
lng = Double.valueOf(full.get(x));
x += 1;
LatLng pos = new LatLng(lat, lng);
mapAPI.addMarker(new MarkerOptions().position(pos).title(name));
mark = new LatLng(lat,lng);
markerCoords.add(mark);
}
}
#Override
public void onFailure() {
}
}
}
and this is the code for parsing the JSON from the database any help would be greatly appreciated.
package com.example.defiblocator;
import android.app.Application;
import android.os.AsyncTask;
import android.widget.TextView;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class fetchData extends AsyncTask <Void,Void,Void>{
CallbackInterface callbackInterface;
String data = "";
String json_url;
String singleParsed = "";
public String dataParsed = "";
String sent;
public fetchData(CallbackInterface callbackInterface) {
this.callbackInterface = callbackInterface;
}
public Integer x = 0;
#Override
protected void onPreExecute(){
json_url = "http://defiblocator.ml/json_get_data.php";
dataParsed = "";
}
#Override
protected Void doInBackground(Void... voids) {
try {
URL url = new URL(json_url);
HttpURLConnection httpURLConnection = (HttpURLConnection)url.openConnection();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
String line = "";
while(line != null){
line = bufferedReader.readLine();
data = data + line;
}
JSONArray JA = new JSONArray(data);
for(int i =0 ; i <JA.length(); i++){
JSONObject JO = (JSONObject) JA.get(i);
singleParsed = JO.get("name") + "," + JO.get("lat") + "," +JO.get("lng") + "," ;
dataParsed = dataParsed + singleParsed ;
}
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException | JSONException e){
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
MainActivity.data.setText(dataParsed);
callbackInterface.onSuccess(dataParsed);
}
}
You could use a simple distance formula to archive this:
private Double distance(Double lat1, Double lon1, Double lat2, Double lon2) {
return Math.sqrt (Math.pow((lat1 - lat2), 2) - Math.pow((lon1 - lon2), 2));
}
// The user Location
currentLat = xxxx;
currentLon = xxxx;
if ((markerCoords != null) && (markerCoords.size() > 0)) {
LatLng near = markerCoords.get(0);
for (int x = 1; x < markerCoords.size(); x++) {
Double lat = markerCoords.get(x).latitude;
Double lon = markerCoords.get(x).longitude;
Double currentMarkerdistance = distance(
currentLat,
currentLon,
markerCoords.get(x).latitude,
markerCoords.get(x).longitude);
Double nearMarkerdistance = distance(
currentLat,
currentLon,
near.latitude,
near.longitude);
if (currentMarkerdistance < nearMarkerdistance) {
near = markerCoords.get(x);
}
}
}
// After this process the near variable will hold the near marker
Related
there! I am a brand new learner of android and geocoding. And I wonder how I can display the current address rather than showing the "Here you are" message. I know I was supposed to use the getFromLocation() method to accomplish my goal. However, I do not know how I can do that and where to put it.
import android.Manifest;
import android.annotation.SuppressLint;
import android.content.pm.PackageManager;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.os.Bundle;
import android.widget.Toast;
import androidx.core.app.ActivityCompat;
import androidx.core.content.ContextCompat;
import androidx.fragment.app.FragmentActivity;
import com.google.android.gms.location.FusedLocationProviderClient;
import com.google.android.gms.location.LocationCallback;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationResult;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.tasks.OnSuccessListener;
import java.io.IOException;
import java.util.List;
import java.util.Locale;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback {
private final int REQUEST_LOCATION_PERMISSIONS = 0;
private float mZoomLevel = 15;
private GoogleMap mMap;
private FusedLocationProviderClient mClient;
private LocationRequest mLocationRequest;
private LocationCallback mLocationCallback;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
// 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);
// Create location request
mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(5000);
mLocationRequest.setFastestInterval(3000);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
mClient = LocationServices.getFusedLocationProviderClient(this);
// Create location callback
mLocationCallback = new LocationCallback() {
#Override
public void onLocationResult(LocationResult locationResult) {
if (locationResult != null) {
for (Location location : locationResult.getLocations()) {
updateMap(location);
}
}
}
};
mClient = LocationServices.getFusedLocationProviderClient(this);
}
private void updateMap(Location location) {
// Get current location
LatLng myLatLng = new LatLng(location.getLatitude(),
location.getLongitude());
// Place a marker at the current location
MarkerOptions myMarker = new MarkerOptions()
.title("Here you are!")
.position(myLatLng);
// Remove previous marker
mMap.clear();
// Add new marker
mMap.addMarker(myMarker);
// Move and zoom to current location at the street level
CameraUpdate update = CameraUpdateFactory.
newLatLngZoom(myLatLng, mZoomLevel);
mMap.animateCamera(update);
}
#Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
mMap.setOnCameraMoveListener(new GoogleMap.OnCameraMoveListener() {
#Override
public void onCameraMove() {
CameraPosition cameraPosition = mMap.getCameraPosition();
mZoomLevel = cameraPosition.zoom;
}
});
mMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
#Override
public boolean onMarkerClick(Marker marker) {
Toast.makeText(MapsActivity.this,"Lat: " + marker.getPosition().latitude +
"\nLong: " + marker.getPosition().longitude, Toast.LENGTH_LONG).show();
return false;
}
});
}
#Override
public void onPause() {
super.onPause();
mClient.removeLocationUpdates(mLocationCallback);
}
#SuppressLint("MissingPermission")
#Override
public void onResume() {
super.onResume();
if (hasLocationPermission()) {
mClient.requestLocationUpdates(mLocationRequest, mLocationCallback, null);
}
}
private boolean hasLocationPermission() {
// Request fine location permission if not already granted
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this ,
new String[] { Manifest.permission.ACCESS_FINE_LOCATION },
REQUEST_LOCATION_PERMISSIONS);
return false;
}
return true;
}
}
I was trying to add the following to the code to change the message to a specific location:
Geocoder geocoder;
List<Address> addresses;
geocoder = new Geocoder(this, Locale.getDefault());
try {
addresses = geocoder.getFromLocation(location.getLatitude(), location.getLongitude(), 1);
updateMap(location);
} catch (Exception e) {
e.printStackTrace();
}
}
getFromAddress method return list of possible address.you can get full address like bellow code.
List<Address> fromLocation = geocoder.getFromLocation(location.latitude, location.longitude, 1);
Address address = fromLocation.get(0);
String zipCode = address.getPostalCode());
String city = address.getLocality();
String subAdmin = address.getSubAdminArea();
String countryCode = address.getCountryCode());
String state = address.getAdminArea());
Also you can update your marker as bellow
MarkerOptions markerOptions = new MarkerOptions();
markerOptions.draggable(true);
markerOptions.position(latLng);
markerOptions.title(city);// your text put here
map.addMarker(markerOptions);
In this code, I need to send name and number to the location database with the map's long and lat. Marker's long and lat sending to the firebase without any issue but name and number not sending to the firebase. I cannot find the issue of the code because in the logcat there are not showing any issue. Can you please help me to fix this.
package com.example.policeemergencysystem;
import androidx.annotation.RequiresApi;
import androidx.fragment.app.FragmentActivity;
import android.os.Build;
import android.os.Bundle;
import com.example.policeemergencysystem.Prevelant.Prevelant;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.BitmapDescriptor;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import android.Manifest;
import android.app.Activity;
import android.content.Intent;
import android.content.IntentSender;
import android.content.pm.PackageManager;
import android.location.Address;
import android.location.Geocoder;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import com.example.policeemergencysystem.Model.AdminOrders;
import androidx.annotation.NonNull;
import androidx.fragment.app.FragmentActivity;
import com.google.android.gms.common.api.ApiException;
import com.google.android.gms.common.api.ResolvableApiException;
import com.google.android.gms.location.LocationRequest;
import com.google.android.gms.location.LocationServices;
import com.google.android.gms.location.LocationSettingsRequest;
import com.google.android.gms.location.LocationSettingsResponse;
import com.google.android.gms.location.LocationSettingsStates;
import com.google.android.gms.location.LocationSettingsStatusCodes;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.CameraPosition;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.example.policeemergencysystem.Prevelant.Prevelant;
import com.google.firebase.database.ValueEventListener;
import java.io.IOException;
import java.util.HashMap;
import java.util.List;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback{
private GoogleMap mMap;
private Button doneBtn;
TextView backBtn;
Marker myMarker;
LocationManager locationManager;
private static final String TAG = "MainActivity";
private String name;
private String userID = "", userNAME = "", userPHONE = "";
DatabaseReference ordersRef = FirebaseDatabase.getInstance().getReference()
.child("Location")
.child(Prevelant.currentOnlineUser.getUsername());
#RequiresApi(api = Build.VERSION_CODES.M)
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
doneBtn = (Button) findViewById(R.id.doneBtn);
backBtn = (TextView) findViewById(R.id.backBtn);
userID = getIntent().getStringExtra("uid");
userNAME = getIntent().getStringExtra("uname");
userPHONE = getIntent().getStringExtra("uphone");
// 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);
LocationRequest mLocationRequest = new LocationRequest();
mLocationRequest.setInterval(10);
mLocationRequest.setSmallestDisplacement(10);
mLocationRequest.setFastestInterval(10);
mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
LocationSettingsRequest.Builder builder = new
LocationSettingsRequest.Builder();
builder.addLocationRequest(mLocationRequest);
Task<LocationSettingsResponse> task= LocationServices.getSettingsClient(this).checkLocationSettings(builder.build());
task.addOnCompleteListener(new OnCompleteListener<LocationSettingsResponse>() {
#Override
public void onComplete(Task<LocationSettingsResponse> task) {
try {
LocationSettingsResponse response = task.getResult(ApiException.class);
// All location settings are satisfied. The client can initialize location
// requests here.
} catch (ApiException exception) {
switch (exception.getStatusCode()) {
case LocationSettingsStatusCodes.RESOLUTION_REQUIRED:
// Location settings are not satisfied. But could be fixed by showing the
// user a dialog.
try {
// Cast to a resolvable exception.
ResolvableApiException resolvable = (ResolvableApiException) exception;
// Show the dialog by calling startResolutionForResult(),
// and check the result in onActivityResult().
resolvable.startResolutionForResult(
MapsActivity.this,
101);
} catch (IntentSender.SendIntentException e) {
// Ignore the error.
} catch (ClassCastException e) {
// Ignore, should be an impossible error.
}
break;
case LocationSettingsStatusCodes.SETTINGS_CHANGE_UNAVAILABLE:
// Location settings are not satisfied. However, we have no way to fix the
// settings so we won't show the dialog.
break;
}
}
}
});
locationManager = (LocationManager) getSystemService(LOCATION_SERVICE);
if (checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
return;
}
//Check whether the network provider is enabled
if (locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)){
locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, 0, 0, new LocationListener() {
#Override
public void onLocationChanged(Location location) {
//Get the Latitude
double latitude = location.getLatitude();
//Get the Longitude
double longitude = location.getLongitude();
//Instantiate the class, LatLng
LatLng latLng = new LatLng(latitude, longitude);
//Instantiate the class, GeoCoder
Geocoder geocoder = new Geocoder(getApplicationContext());
try {
List<Address> addressList = geocoder.getFromLocation(latitude, longitude, 1);
String str = addressList.get(0).getLocality()+",";
str += addressList.get(0).getCountryName()+",";
str += addressList.get(0).getPostalCode();
mMap.addMarker(new MarkerOptions().position(latLng).title(str));
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(latLng, 14.0f));
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
}
});
}
else if(locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)){
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, new LocationListener() {
#Override
public void onLocationChanged(Location location) {
//Get the Latitude
double latitude = location.getLatitude();
//Get the Longitude
double longitude = location.getLongitude();
//Instantiate the class, LatLng
LatLng latLng = new LatLng(latitude, longitude);
String name = new String(Prevelant.currentOnlineUser.getUsername());
//Instantiate the class, GeoCoder
Geocoder geocoder = new Geocoder(getApplicationContext());
try {
List<Address> addressList = geocoder.getFromLocation(latitude, longitude, 1);
String str = addressList.get(0).getLocality()+",";
str += addressList.get(0).getCountryName()+",";
str += addressList.get(0).getPostalCode();
mMap.addMarker(new MarkerOptions().position(latLng).title(str));
CameraPosition cameraPosition = new CameraPosition.Builder()
.target(latLng)
.zoom(17).build();
//Zoom in and animate the camera.
mMap.animateCamera(CameraUpdateFactory.newCameraPosition(cameraPosition));
} catch (IOException e) {
e.printStackTrace();
}
}
#Override
public void onStatusChanged(String provider, int status, Bundle extras) {
}
#Override
public void onProviderEnabled(String provider) {
}
#Override
public void onProviderDisabled(String provider) {
}
});
}
}
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
final LocationSettingsStates states = LocationSettingsStates.fromIntent(data);
switch (requestCode) {
case 101:
switch (resultCode) {
case Activity.RESULT_OK:
// All required changes were successfully made
Toast.makeText(MapsActivity.this,states.isLocationPresent()+"",Toast.LENGTH_SHORT).show();
break;
case Activity.RESULT_CANCELED:
// The user was asked to change settings, but chose not to
Toast.makeText(MapsActivity.this,"Canceled",Toast.LENGTH_SHORT).show();
break;
default:
break;
}
break;
}
}
#Override
public void onMapReady(final GoogleMap googleMap) {
mMap = googleMap;
Toast.makeText(this, "Please be patience until we find your current location...", Toast.LENGTH_SHORT).show();
mMap.setOnMapLongClickListener(new GoogleMap.OnMapLongClickListener() {
#Override
public void onMapLongClick(LatLng latLng) {
// First check if myMarker is null
if (myMarker == null) {
// Marker was not set yet. Add marker:
myMarker = googleMap.addMarker(new MarkerOptions()
.position(latLng)
.title("Accidnet Location")
.snippet("Put the marker to your accident location")
.icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE)));
doneBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(MapsActivity.this, "Your location has been placed!", Toast.LENGTH_SHORT).show();
HashMap<String, Object> userMap = new HashMap<>();
DatabaseReference myRef = FirebaseDatabase.getInstance().getReference().child("Location").child(Prevelant.currentOnlineUser.getUsername());
myRef.child("name").setValue(userNAME);
myRef.child("phone").setValue(userPHONE);
myRef.child(Prevelant.currentOnlineUser.getUsername()).updateChildren(userMap);
finish();
Intent intent = new Intent(MapsActivity.this, LoginActivity.class);
startActivity(intent);
}
});
} else {
// Marker already exists, just update it's position
myMarker.setPosition(latLng);
LatLng myLatLng = new LatLng(myMarker.getPosition().latitude, myMarker.getPosition().longitude);
}
HashMap<String, Object> adminMap = new HashMap<>();
DatabaseReference myRef = FirebaseDatabase.getInstance().getReference().child("Location").child(Prevelant.currentOnlineUser.getUsername());
LatLng myLatLng = new LatLng(myMarker.getPosition().latitude, myMarker.getPosition().longitude);
myRef.child("latitude").setValue(myLatLng.latitude);
myRef.child("longitude").setValue(myLatLng.longitude);
myRef.child(Prevelant.currentOnlineUser.getUsername()).updateChildren(adminMap);
}
});
}
}
I have an Android Studio application that uses Google Maps, wherein I want to implement a "tag your location". What I want to happen is, the user could tag/input his location in google maps so other users could find his location.
For example, I am a stall owner and I want to input my location in a specific part of the market place so people could find directions to my stall.
Is there a way how to do that? And if yes, help me how to do it. Thanks in advance.
Here is my MapsActivity.java code:
package com.example.kliwa_000.sholocoo;
import android.Manifest;
import android.app.ProgressDialog;
import android.content.pm.PackageManager;
import android.graphics.Color;
import android.location.Location;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.ActivityCompat;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.maps.CameraUpdate;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.OnMapReadyCallback;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.BitmapDescriptorFactory;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.Marker;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.Polyline;
import com.google.android.gms.maps.model.PolylineOptions;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import Modules.DirectionFinder;
import Modules.DirectionFinderListener;
import Modules.Route;
public class MapsActivity extends FragmentActivity implements OnMapReadyCallback, DirectionFinderListener{
private GoogleMap mMap;
private EditText destination, origin;
private Button btnFind;
private List<Marker> originMarkers = new ArrayList<>();
private List<Marker> destinationMarkers = new ArrayList<>();
private List<Polyline> polylinePaths = new ArrayList<>();
private ProgressDialog progressDialog;
int PROXIMITY_RADIUS = 10000;
double latitude, longitude;
double end_latitude, end_longitude;
public static final String TAG = MapsActivity.class.getSimpleName();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
Bundle bundle = getIntent().getExtras();
if (bundle != null){
if (bundle.get("some") != null){
Toast.makeText(getApplicationContext(), "" + bundle.get("some"), Toast.LENGTH_SHORT).show();
}
}
SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map);
mapFragment.getMapAsync(this);
btnFind = (Button) findViewById(R.id.btnFind);
destination = (EditText) findViewById(R.id.destination);
origin = (EditText) findViewById(R.id.origin);
btnFind.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
sendRequest();
}
});
}
private void sendRequest(){
String Sdestination = destination.getText().toString();
String Sorigin = origin.getText().toString();
try{
new DirectionFinder(this, Sorigin, Sdestination).execute();
} catch (UnsupportedEncodingException e){
e.printStackTrace();
}
}
private void setUpMap(){
mMap.addMarker(new MarkerOptions().position(new LatLng(0, 0)).title("Marker"));
}
private void handleNewLocation(Location location){
Log.d(TAG, location.toString());
}
#Override
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
CameraUpdate zoom = CameraUpdateFactory.zoomTo(200);
mMap.moveCamera(zoom);
mMap.animateCamera(zoom);
mMap.setMapType(GoogleMap.MAP_TYPE_SATELLITE);
LatLng userlocation = new LatLng(0, 0);
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_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.INTERNET
}, 10);
}
return;
}
mMap.setMyLocationEnabled(true);
// mMap.addMarker(new MarkerOptions().position(userlocation).title("Current Location"));
/*LatLng seveneleven = new LatLng(16.4088, 120.5978 );
mMap.addMarker(new MarkerOptions().position(seveneleven).title("7/11 Gov. Pack").snippet("Carrots: Php 40/kilo"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(seveneleven));
LatLng ezzerm = new LatLng(16.4087, 120.5993 );
mMap.addMarker(new MarkerOptions().position(ezzerm).title("SM Baguio City").snippet("Carrots: Php 35/kilo"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(ezzerm));
LatLng burnham = new LatLng(16.4093, 120.5950 );
mMap.addMarker(new MarkerOptions().position(burnham).title("Burnham Park").snippet("Carrots: Php 45/kilo"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(burnham));
LatLng whitehouse = new LatLng(16.477949, 120.502748);*/
}
#Override
public void onDirectionFinderStart() {
progressDialog = ProgressDialog.show(this, "Please wait.",
"Finding direction..!", true);
if (originMarkers != null) {
for (Marker marker : originMarkers) {
marker.remove();
}
}
if (destinationMarkers != null) {
for (Marker marker : destinationMarkers) {
marker.remove();
}
}
if (polylinePaths != null) {
for (Polyline polyline:polylinePaths ) {
polyline.remove();
}
}
}
#Override
public void onDirectionFinderSuccess(List<Route> routes) {
progressDialog.dismiss();
polylinePaths = new ArrayList<>();
originMarkers = new ArrayList<>();
destinationMarkers = new ArrayList<>();
for (Route route : routes) {
mMap.moveCamera(CameraUpdateFactory.newLatLngZoom(route.startLocation, 16));
((TextView) findViewById(R.id.tvDuration)).setText(route.duration.text);
((TextView) findViewById(R.id.tvDistance)).setText(route.distance.text);
originMarkers.add(mMap.addMarker(new MarkerOptions()
.icon(BitmapDescriptorFactory.fromResource(R.drawable.start_blue))
.title(route.startAddress)
.position(route.startLocation)));
destinationMarkers.add(mMap.addMarker(new MarkerOptions()
.icon(BitmapDescriptorFactory.fromResource(R.drawable.end_green))
.title(route.endAddress)
.position(route.endLocation)));
PolylineOptions polylineOptions = new PolylineOptions().
geodesic(true).
color(Color.BLUE).
width(10);
for (int i = 0; i < route.points.size(); i++)
polylineOptions.add(route.points.get(i));
polylinePaths.add(mMap.addPolyline(polylineOptions));
}
}
}
Honestly, my code is a little bit messy, but I'm trying to fix it.
I'd like to check GPS both when the app is started and when the refresh button is hit, and use those data points, in the form of mLatitude and mLongitude to call the weather api. Eventually I'm going to geocode the city but right now for debugging purposes I'm outputting the GPS coordinates to the locationLabel textview.
my MainActivity.java:
package com.example.paxie.stormy.ui;
import android.Manifest;
import android.annotation.TargetApi;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.pm.PackageManager;
import android.graphics.drawable.Drawable;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Build;
import android.os.Bundle;
import android.provider.Settings;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import com.example.paxie.stormy.GPS_Service;
import com.example.paxie.stormy.R;
import com.example.paxie.stormy.weather.Current;
import com.example.paxie.stormy.weather.Day;
import com.example.paxie.stormy.weather.Forecast;
import com.example.paxie.stormy.weather.Hour;
import com.squareup.okhttp.Call;
import com.squareup.okhttp.Callback;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.io.IOException;
import butterknife.Bind;
import butterknife.ButterKnife;
import butterknife.OnClick;
public class MainActivity extends AppCompatActivity {
public static final String TAG = MainActivity.class.getSimpleName();
public static final String DAILY_FORECAST = "DAILY_FORECAST";
public static final String HOURLY_FORECAST = "HOURLY_FORECAST";
private Forecast mForecast;
private double mLatitude;
private double mLongitude;
private BroadcastReceiver broadcastReceiver;
#Bind(R.id.timeLabel)
TextView mTimeLabel;
#Bind(R.id.temperatureLabel)
TextView mTemperatureLabel;
#Bind(R.id.humidityValue)
TextView mHumidityValue;
#Bind(R.id.precipValue)
TextView mPrecipValue;
#Bind(R.id.summaryLabel)
TextView mSummaryLabel;
#Bind(R.id.iconImageView)
ImageView mIconImageView;
#Bind(R.id.refreshImageView)
ImageView mRefreshImageView;
#Bind(R.id.progressBar)
ProgressBar mProgressBar;
#Bind(R.id.locationLabel)
TextView mLocationlabel;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ButterKnife.bind(this);
mProgressBar.setVisibility(View.INVISIBLE);
mRefreshImageView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
getForecast();
}
});
getForecast();
Log.d(TAG, "Main UI code is running!");
}
private void getForecast() {
if(!runtime_permissions())
checkGPS();
String apiKey = "1621390f8c36997cb1904914b726df52";
String forecastUrl = "https://api.forecast.io/forecast/" + apiKey +
"/" + mLatitude + "," + mLongitude;
if (isNetworkAvailable()) {
toggleRefresh();
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder()
.url(forecastUrl)
.build();
Call call = client.newCall(request);
call.enqueue(new Callback() {
#Override
public void onFailure(Request request, IOException e) {
runOnUiThread(new Runnable() {
#Override
public void run() {
toggleRefresh();
}
});
alertUserAboutError();
}
#Override
public void onResponse(Response response) throws IOException {
runOnUiThread(new Runnable() {
#Override
public void run() {
toggleRefresh();
}
});
try {
String jsonData = response.body().string();
Log.v(TAG, jsonData);
if (response.isSuccessful()) {
mForecast = parseForecastDetails(jsonData);
runOnUiThread(new Runnable() {
#Override
public void run() {
updateDisplay();
}
});
} else {
alertUserAboutError();
}
} catch (IOException e)
{
Log.e(TAG, "Exception caught: ", e);
} catch (JSONException e) {
e.printStackTrace();
}
}
});
} else {
Toast.makeText(this, "Network is currently unavailable!", Toast.LENGTH_LONG).show();
}
}
private void toggleRefresh() {
if (mProgressBar.getVisibility() == View.INVISIBLE) {
mProgressBar.setVisibility(View.VISIBLE);
mRefreshImageView.setVisibility(View.INVISIBLE);
} else {
mProgressBar.setVisibility(View.INVISIBLE);
mRefreshImageView.setVisibility(View.VISIBLE);
}
}
private void updateDisplay() {
mLocationlabel.setText(mLatitude + " " + mLongitude);
Current current = mForecast.getCurrent();
mTemperatureLabel.setText(current.getTemperature() + "");
mTimeLabel.setText("At " + current.getFormattedTime() + " it will be:");
mHumidityValue.setText(current.getHumidity() + "");
mPrecipValue.setText(current.getPrecipChance() + "%");
mSummaryLabel.setText(current.getSummary());
Drawable drawable = ContextCompat.getDrawable(this, current.getIconId());
mIconImageView.setImageDrawable(drawable);
}
private Forecast parseForecastDetails(String jsonData) throws JSONException {
Forecast forecast = new Forecast();
forecast.setCurrent(getCurrentDetails(jsonData));
forecast.setHourlyForecast(getHourlyForecast(jsonData));
forecast.setDailyForecast(getDailyForecast(jsonData));
return forecast;
}
private Day[] getDailyForecast(String jsonData) throws JSONException {
JSONObject forecast = new JSONObject(jsonData);
String timezone = forecast.getString("timezone");
JSONObject daily = forecast.getJSONObject("daily");
JSONArray data = daily.getJSONArray("data");
Day[] days = new Day[data.length()];
for (int i = 0; i < data.length(); i++) {
JSONObject jsonDay = data.getJSONObject(i);
Day day = new Day();
day.setSummary(jsonDay.getString("summary"));
day.setIcon(jsonDay.getString("icon"));
day.setTemperatureMax(jsonDay.getDouble("temperatureMax"));
day.setTime(jsonDay.getLong("time"));
day.setTimeZone(timezone);
days[i] = day;
}
return days;
}
private Hour[] getHourlyForecast(String jsonData) throws JSONException {
JSONObject forecast = new JSONObject(jsonData);
String timezone = forecast.getString("timezone");
JSONObject hourly = forecast.getJSONObject("hourly");
JSONArray data = hourly.getJSONArray("data");
Hour[] hours = new Hour[data.length()];
for (int i = 0; i < data.length(); i++) {
JSONObject jsonHour = data.getJSONObject(i);
Hour hour = new Hour();
hour.setSummary(jsonHour.getString("summary"));
hour.setTemperature(jsonHour.getDouble("temperature"));
hour.setIcon(jsonHour.getString("icon"));
hour.setTime(jsonHour.getLong("time"));
hour.setTimeZone(timezone);
hours[i] = hour;
}
return hours;
}
private Current getCurrentDetails(String jsonData) throws JSONException {
JSONObject forecast = new JSONObject(jsonData);
String timezone = forecast.getString("timezone");
Log.i(TAG, "From JSON: " + timezone);
JSONObject currently = forecast.getJSONObject("currently");
Current current = new Current();
current.setHumidity(currently.getDouble("humidity"));
current.setTime(currently.getLong("time"));
current.setIcon(currently.getString("icon"));
current.setPrecipChance(currently.getDouble("precipProbability"));
current.setSummary(currently.getString("summary"));
current.setTemperature(currently.getDouble("temperature"));
current.setTimeZone(timezone);
Log.d(TAG, current.getFormattedTime());
return current;
}
private boolean isNetworkAvailable() {
ConnectivityManager manager = (ConnectivityManager)
getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = manager.getActiveNetworkInfo();
boolean isAvailable = false;
if (networkInfo != null && networkInfo.isConnected()) {
isAvailable = true;
}
return isAvailable;
}
private void alertUserAboutError() {
AlertDialogFragment dialog = new AlertDialogFragment();
dialog.show(getFragmentManager(), "error_dialog");
}
#OnClick(R.id.dailyButton)
public void startDailyActivity(View view) {
Intent intent = new Intent(this, DailyForecastActivity.class);
intent.putExtra(DAILY_FORECAST, mForecast.getDailyForecast());
startActivity(intent);
}
#OnClick(R.id.hourlyButton)
public void startHourlyActivity(View view) {
Intent intent = new Intent(this, HourlyForecastActivity.class);
intent.putExtra(HOURLY_FORECAST, mForecast.getHourlyForecast());
startActivity(intent);
}
private void checkGPS() {
if (broadcastReceiver == null) {
broadcastReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
mLatitude = (double) intent.getExtras().get("latitude");
mLongitude = (double) intent.getExtras().get("longitude");
}
};
}
registerReceiver(broadcastReceiver, new IntentFilter("location_update"));
}
private boolean runtime_permissions() {
if (Build.VERSION.SDK_INT >= 23 && ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}, 100);
return true;
}
return false;
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == 100) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED && grantResults[1] == PackageManager.PERMISSION_GRANTED) {
getForecast();
} else {
runtime_permissions();
}
}
}
#Override
protected void onResume() {
super.onResume();
checkGPS();
}
}
my GPSservice.java:
package com.example.paxie.stormy;
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;
import android.provider.Settings;
import android.support.annotation.Nullable;
/**
* Created by paxie on 10/27/16.
*/
public class GPS_Service extends Service {
private LocationListener listener;
private LocationManager locationManager;
#Nullable
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onCreate() {
listener = new LocationListener() {
#Override
public void onLocationChanged(Location location) {
Intent i = new Intent("location_update");
i.putExtra("coordinates",location.getLongitude()+" "+location.getLatitude());
i.putExtra("longitude", location.getLongitude());
i.putExtra("latitude", location.getLatitude());
sendBroadcast(i);
}
#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);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(i);
}
};
locationManager = (LocationManager) getApplicationContext().getSystemService(Context.LOCATION_SERVICE);
//noinspection MissingPermission
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,3000,0,listener);
}
#Override
public void onDestroy() {
super.onDestroy();
if(locationManager != null){
//noinspection MissingPermission
locationManager.removeUpdates(listener);
}
}
}
Here are two things you can try:
1. Please ensure you have included the ACCESS_FINE_LOCATION and ACCESS_COARSE_LOCATION permissions in your manifest. If your app targets Android API 23 and above, you will need to include runtime permission handling.
2. Instead of having a LocationListener object as a class member, you should have your Service implement it as an interface and implement its onLocationChanged() method.
Apart from this, you really should consider using the location APIs' in Google Play Services, rather than those in AOSP (i.e. android.location).
See Making Your App Location-Aware
This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 2 years ago.
Main Activity
trying to add google map please help as soon as u can
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.json.JSONObject;
import android.app.ActionBar;
import android.content.Intent;
import android.graphics.Color;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import com.google.android.gms.maps.CameraUpdateFactory;
import com.google.android.gms.maps.GoogleMap;
import com.google.android.gms.maps.SupportMapFragment;
import com.google.android.gms.maps.model.LatLng;
import com.google.android.gms.maps.model.MarkerOptions;
import com.google.android.gms.maps.model.PolylineOptions;
import com.parse.ParseAnalytics;
import com.parse.ParseUser;
public class OnscreenActivity extends FragmentActivity {
private static final LatLng sydney = new LatLng(30.8894669, 75.8246729);
private static final LatLng connct = new LatLng(30.8914863, 75.874398);
GoogleMap googleMap;
final String TAG1 = "PathGoogleMapActivity";
public static final String TAG = OnscreenActivity.class.getSimpleName();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_map);
SupportMapFragment fm = (SupportMapFragment) getSupportFragmentManager()
.findFragmentById(R.id.fragment1);
googleMap = fm.getMap();
ParseAnalytics.trackAppOpened(getIntent());
ParseUser currentUser = ParseUser.getCurrentUser();
if (currentUser == null) {
navigateToLogin();
} else {
Log.i(TAG, currentUser.getUsername());
}
ActionBar actionbar = getActionBar();
actionbar.show();
MarkerOptions options = new MarkerOptions();
options.position(sydney);
options.position(connct);
googleMap.addMarker(options);
String url = getMapsApiDirectionsUrl();
ReadTask downloadTask = new ReadTask();
downloadTask.execute(url);
googleMap.moveCamera(CameraUpdateFactory.newLatLngZoom(connct, 16));
addMarkers();
}
private void addMarkers() {
// TODO Auto-generated method stub
if (googleMap != null) {
googleMap.addMarker(new MarkerOptions().position(sydney).title(
"First Point"));
googleMap.addMarker(new MarkerOptions().position(connct).title(
"Second Point"));
}
}
private String getMapsApiDirectionsUrl() {
String waypoints = "waypoints=optimize:true|" + sydney.latitude + ","
+ sydney.longitude + "|" + "|" + connct.latitude + ","
+ connct.longitude;
String sensor = "sensor=false";
String params = waypoints + "&" + sensor;
String output = "json";
String url = "https://maps.googleapis.com/maps/api/directions/"
+ output + "?" + params;
return url;
}
private class ReadTask extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... url) {
String data = "";
try {
HttpConnection http = new HttpConnection();
data = http.readUrl(url[0]);
} catch (Exception e) {
Log.d("Background Task", e.toString());
}
return data;
}
#Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
new ParserTask().execute(result);
}
}
private class ParserTask extends
AsyncTask<String, Integer, List<List<HashMap<String, String>>>> {
#Override
protected List<List<HashMap<String, String>>> doInBackground(
String... jsonData) {
JSONObject jObject;
List<List<HashMap<String, String>>> routes = null;
try {
jObject = new JSONObject(jsonData[0]);
PathJsonParser parser = new PathJsonParser();
routes = parser.parse(jObject);
} catch (Exception e) {
e.printStackTrace();
}
return routes;
}
#Override
protected void onPostExecute(List<List<HashMap<String, String>>> routes) {
ArrayList<LatLng> points = null;
PolylineOptions polyLineOptions = null;
// traversing through routes
for (int i = 0; i < routes.size(); i++) {
points = new ArrayList<LatLng>();
polyLineOptions = new PolylineOptions();
List<HashMap<String, String>> path = routes.get(i);
for (int j = 0; j < path.size(); j++) {
HashMap<String, String> point = path.get(j);
double lat = Double.parseDouble(point.get("lat"));
double lng = Double.parseDouble(point.get("lng"));
LatLng position = new LatLng(lat, lng);
points.add(position);
}
polyLineOptions.addAll(points);
polyLineOptions.width(2);
polyLineOptions.color(Color.BLUE);
}
googleMap.addPolyline(polyLineOptions);
}
}
private void navigateToLogin() {
Intent intent = new Intent(this, Login.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
}
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.map, menu);
return true;
}
public boolean onOptionsItemSelected(MenuItem item) {
int itemId = item.getItemId();
if (itemId == R.id.action_logout) {
ParseUser.logOut();
navigateToLogin();
}
if (itemId == R.id.options) {
Intent intent = new Intent(this, UserOptions.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);
}
return super.onOptionsItemSelected(null);
}
}
It is impossible for us to tell you exactly why the routes List is null in your onPostExecute in the ParserTask, but it is.
If it is intended that your doInBackground in ParserTask can return null, you should at least check if the routes variable is null before you attempt to do anything with it. This will not fix the error and might result in your app not doing what it should, but as I mentioned previously, it's impossible to tell you any more without the full log.
if (routes == null) return; will suppress the error, but only solve your problem if you read multiple json files and some of them actually parse.