# How to know if an Android device is near an address google maps api

I’m developing an Android application which receives a given address. I would like to only let the app run on the device, if the user is on that address, or closer to it.

Is that possible to do only with google maps api?

## Answer

You could get the address and from the address get the latitude and longitude:

```Geocoder coder = new Geocoder(this);
List<Address> address;

try {
address = coder.getFromLocationName(strAddress,5);
if (address == null) {
return null;
}
Address location = address.get(0);
location.getLatitude();
location.getLongitude();

}
```

And then compare it with your location:

```if (distance(mylocation.latitude, mylocation.longitude,   location.getLatitude(), location.getLongitude()) < 0.1) { // if distance < 0.1

//   launch the activity
}else {
finish();
}

/** calculates the distance between two locations in MILES */
private double distance(double lat1, double lng1, double lat2, double lng2) {

double earthRadius = 3958.75; // in miles, change to 6371 for kilometers

double dLat = Math.toRadians(lat2-lat1);
double dLng = Math.toRadians(lng2-lng1);

double sindLat = Math.sin(dLat / 2);
double sindLng = Math.sin(dLng / 2);

double a = Math.pow(sindLat, 2) + Math.pow(sindLng, 2)
* Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2));

double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));

double dist = earthRadius * c;

return dist;
}
```

EDIT: As @FelipeMosso was saying, you can also use distanceBetween that computes the approximate distance in meters between two locations or the distanceTo that gives you the distance between where you are at and the destination..