Activity_2.java

private boolean permissions_ok = false;
private static int LOCATION_PERMISSION_CODE = 100;

public void requestPermission(View view) {
  if (ActivityCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
    permissions_ok = false;
    ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION}, LOCATION_PERMISSION_CODE);
  } 
  else {
    permissions_ok = true;
  }
}

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
  super.onRequestPermissionsResult(requestCode, permissions, grantResults);
  if (requestCode == LOCATION_PERMISSION_CODE) {
    if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
      permissions_ok = true;
    } 
    else {
      permissions_ok = false;
    }
  }
}