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Opening maps via intent with preselected location

I'm trying to make an app that will use an Place autocomplete fragment in one activity and when I select a place in it, on a click of a button, I'm supposed to open another activity (Google Maps activity) and it's supposed to get the location that I chose in the first one. I've tried passing Longitude and Latitude from Main class to Maps class, but it just crashes my app. Anyone have any idea how to fix?
Thank you in advance!
EDIT: Sample of what I've tried so far:
/*This is the main class where my autocomplete fragment is*/
Double Lat;
Double lang;
public void onPlaceSelected(Place place) {
// TODO: Get info about the selected place.
// Lat = place.getLatLng().latitude;
// lang = place.getLatLng().longitude;
setLang(place.getLatLng().longitude);
setLat(place.getLatLng().latitude);
Log.i(TAG, "Place: " + place.getName());
}
public void setLang(Double langg){
this.lang = langg;
}
public void setLat(Double Latt){
this.Lat = Latt;
}
public Double getLang(){
return lang;
}
public Double getLat(){
return Lat;
}
/* This is the maps class */
MainActivity maAct;
public void onMapReady(GoogleMap googleMap) {
mMap = googleMap;
LatLng place = new LatLng(maAct.getLat(), maAct.getLang());
// LatLng paris = new LatLng(48.8566, 2.3522);
mMap.addMarker(new MarkerOptions().position(place).title("Marker inPlace"));
mMap.moveCamera(CameraUpdateFactory.newLatLng(place));
}

Ok, you may consider to pass the latitude and longitude by Intent.
// MainActivity
Intent intent = new Intent(MainActivity.this, MapActivity.class);
intent.putExtra("lat", Lat);
intent.putExtra("lng", lang);
startActivity(intent);
And..
// Map Activity onMapReady
double lat = getIntent().getDoubleExtra("lat", DEFAULT_LAT);
double lng = getIntent().getDoubleExtra("lng", DEFAULT_LNG);
LatLng place = new LatLng(lat, lng);
mMap.addMarker(new MarkerOptions().position(place).title("Marker inPlace"));
You cannot getValue by maAct, your concept is incorrect.
First if you just
MainActivity maAct;
maAct is not assigned any 'value', so that if you call any methods of maAct, you will get NullPointerException.
Besides, if you really give it a 'value',
// it is totally wrong, just an example only
MainActivity maAct = new MainActivity();
But it is not the same reference so that you cannot get the values you stored before.

What i understand is you want to navigate to the passed latitude and longitude.Here is a sample
String uri = String.format(Locale.ENGLISH, "google.navigation:q=%f,%f", Double.parseDouble(latitude), Double.parseDouble(longitude));
Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(uri));
if(intent.resolveActivity(context.getPackageManager())!=null)
context.startActivity(intent);
You can find more info like creating markers and all here
Edit:
As per your code you want to set the marker.Here is the steps and sample for a working marker example.

Using a variable value from one method in different one in Android Studio

Firstly sorry for asking so many questions here the past couple of weeks, I'm new to android studio and finding it tough to figure out a lot of the core concepts by myself.
In regards to the question, I have a project set up so whatever you type into the "1.2, -1.2" ect parameters you will find you the distance between two places and your answer will be displayed as a toast. However, I want the latitudes and longitueds to be variables.
Button button1=(Button) findViewById(R.id.button1);
button1.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Double distance = 1.0;
int val = 1;
Toast.makeText(getApplicationContext(), "You are " + String.valueOf(distance
(1.2, -1.2, 1.3, -2.4, "K")) + "kilometers away from the flag", Toast.LENGTH_LONG).show(); }
});
I have the following two methods and I want the values LatLng and currentLatitude and currentLongitude doubles for the parameters above.
private void setUpMap() {
mMap.addMarker(new MarkerOptions().position(new LatLng(53.3835,6.5996)).title("Marker"));
}
and
private void handleNewLocation(Location location) {
Log.d(TAG, location.toString());
double currentLatitude = location.getLatitude();
double currentLongitude = location.getLongitude();
LatLng latLng = new LatLng(currentLatitude, currentLongitude);
//mMap.addMarker(new MarkerOptions().position(new LatLng(currentLatitude, currentLongitude)).title("Current Location"));
MarkerOptions options = new MarkerOptions()
.position(latLng)
.title("I am here!");
mMap.addMarker(options);
mMap.moveCamera(CameraUpdateFactory.newLatLng(latLng));
}
Any insight on how to do it would be much appreciated. From what I've read I know I'll need to split the LatLng variable into strings but thats all I can think of so far

If those 2 methods are in the same class then just make those 2 variables attributes of that class, else you will need to pass them to the corresponding classes. I will demonstrate in a simpler example than your code :
public class MyClass(){
private int lat;
private int longt;
//constructors ,setters and getters
public void method1(){
//affecting those attributes with values
lat = 1;
longt = 2;
}
public void method2(){
//simply access the attributes
System.out.println("lat "+lat+" longt "+longt);
}
}
Reading the comments , I think I need to further explain to you that when a variable is declared inside a method, it is local to that method, and therefor it will be "destroyed" (garbage collected or w.e) when that method is done doing it's job. But when a variable is declared outside a method, like the class's attributes, you can still refer to it whenever you need to, until the instance of that class is "destroyed".

Execute async method inside onLocationChanged()

I have a class which extends from AsyncTask and gets data in JSON format from a web service. My android app has to retrieve data asynchronously whenever the location is changed. My android activity implements LocationListener and I am invoking the asynchronous execution in onLocationChanged() method. I have tried setting zero for both minTime and minDistance parameters of requestLocationUpdates() method but the data which is to be retrieved asynchronously is never retrieved.
The code for my onCreate() and onLocationChanged() methods is given below
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_nearby);
locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);
locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, this);
// Hashmap for ListView
albumsList = new ArrayList<HashMap<String, String>>();
}
#Override
public void onLocationChanged(Location location) {
latitude = String.valueOf(location.getLatitude());
longitude = String.valueOf(location.getLatitude());
new MyAsyncTask().execute();
}
The latitude and longitude variables are used in the MyAsyncTask class for getting data with respect to user's current location.
Please tell me what's wrong with my code. I have been looking for the solution since last week but haven't found any.

oke, a little bit confused but let me understand it. You retrieve the data in onLocationChanged() ? example long=111 lat=222 and with your Asyntask you make a GET request to a WS with a json parameter probably long and lat and some other stuff in it ? and if you try to debugg it there are some values in logcat ? or some error ? or did you put the permision in the manifest file ? or in the phones settings ?

did tried debugging??
or
Log??
are you getting any error???
sometimes the location.getLatitute() and location.getLatitute() returns null which may cause null pointer Exception..
that may stopped reaching the MyAsyncTask()
check this may help you..
#Override
public void onLocationChanged(Location location) {
double latit =null;
double longi =null;
do
{
latit=location.getlatitude();
longi=location.getlongitude();
}while(latit!=null && longi!=null);
latitude = String.valueOf(location.getLatitude());
longitude = String.valueOf(location.getLatitude());
new MyAsyncTask().execute();
}
The getlatitude() and getlongitude() function will return double value check this documentation
http://developer.android.com/reference/android/location/Location.html#getLatitude()

Oops My Bad!
The correct code is
#Override
public void onLocationChanged(Location location) {
latitude = String.valueOf(location.getLatitude());
longitude = String.valueOf(location.getLongitude());
new MyAsyncTask().execute();
}

onLocationChange() not getting called? Calculate Distance Travelled -Android

I have this code:
Location newLocation = new Location(LocationManager.GPS_PROVIDER);
Location oldLocation = new Location(LocationManager.GPS_PROVIDER);
float distanceTravelled=0;
onLocationChanged:
#Override
public void onLocationChanged(Location location)
{
oldLocation.set(newLocation);
startactivity();
distanceTravelled+=newLocation.distanceTo(oldLocation);
String stringDistance= Float.toString(distanceTravelled);
TextView distance = (TextView) findViewById(R.id.textDistance);
distance.setText(stringDistance);
}
startactivity:
public void startactivity()
{
GPSTracker gps = new GPSTracker(Live.this);
if(gps.canGetLocation())
{
double latitude = gps.getLatitude();
double longitude = gps.getLongitude();
Toast.makeText(getApplicationContext(), "Your Location is: \nLat: " + latitude + "\nLong: " + longitude, Toast.LENGTH_LONG).show();
newLocation.setLatitude(latitude);
newLocation.setLongitude(longitude);
}
else
{
gps.showSettingsAlert();
}
}
GPSTracker is a separate class which gets the current latitude and longitude (it is working fine!).
GPS updates at min. distance 5 metres and min. time 5 seconds.
Here is my full GPSTracker class: GPSTracker.java
I have added the three permissions in the manifest: fine,coarse and internet.
My problem is the textview inside onLocationChanged never gets changed.
What is the problem? Is onLocationChanged not getting called or there is some logical error (distance always remains zero)?
And how to fix that?

Your function is
public void onLocationChanged(Location location)
but you are not using that parameter anywhere in the function.
It looks like you should add
newLocation.set(location);
after the first line of your function.
At the moment you are calculating the distance between the starting point and itself, and that will always be 0.

Android Variable Scope; or, where the heck is my string

I'm working on a simple Android app, with a GPS listener and a webview.
I can get the latitude and longitude with no issue. The problem is, I want to put the latitude and longitude into a URL (like myurl.com/mypage.php?lat=57&lon=21)... but the variable the data is stored in is confined to its class. I can't figure out how to declare or create a variable that I can use throughout the entire main class. Here's my code:
public class WTest2Activity extends Activity {
public String txt;
public class MyLocationListener implements LocationListener {
public void onLocationChanged(Location loc) {
loc.getLatitude();
loc.getLongitude();
txt = "Latitude: " + loc.getLatitude() + "Longitude: " + loc.getLongitude();
Toast.makeText( getApplicationContext(),txt,Toast.LENGTH_SHORT).show();
}
public void onProviderDisabled(String provider) {
Toast.makeText( getApplicationContext(),"Gps Disabled",Toast.LENGTH_SHORT ).show();
}
public void onProviderEnabled(String provider) {
Toast.makeText( getApplicationContext(),"Gps Enabled",Toast.LENGTH_SHORT).show();
}
public void onStatusChanged(String provider, int status, Bundle extras) {} /* do nothing */
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
/* Use the LocationManager class to obtain GPS locations */
LocationManager mlocManager = (LocationManager)getSystemService(Context.LOCATION_SERVICE);
LocationListener mlocListener = new MyLocationListener();
mlocManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 0, 0, mlocListener);
WebView webview;
webview = (WebView) findViewById(R.id.webview);
webview.getSettings().setJavaScriptEnabled(true);
webview.loadUrl("http://www.myurl.com/page.php?this=" + txt);
}
}

Your OnCreate method is the method called at start of Activity. At that time, txt is null. That's why it doens't show in your url. Then, onLocationChanged sets the value of txt but where are you using this afterwards? nowhere!.
you should move what you do in onCreate to onLocationChanged:
public void onLocationChanged(Location loc) {
loc.getLatitude();
loc.getLongitude();
txt = "Latitude: " + loc.getLatitude() + "Longitude: " + loc.getLongitude();
Toast.makeText( getApplicationContext(),txt,Toast.LENGTH_SHORT).show();
webview.loadUrl("http://www.myurl.com/page.php?this=" + txt);
}

add a new line here:
public class WTest2Activity extends Activity {
public String txt;
public Location location;
then, in your public void onLocationChanged(Location loc), try setting location.setLatitude(loc.getLatitide); and location.setLongitude(loc.getLongitude);
then, you can access your location anywhere with your global variable location

Buddy its just small logical mistake in your code. Let me explain. You are requesting location updates then right after that you are loading URL. Now location listening is different thread which is updating value of txt variable. And updating location takes time. And taken time can be different every time. That is why you need to move your loadUrl code to onLocationChanged method.