get latitude and longitude using zipcode

This is a much simpler solution, assuming the geocoder services are present:

final Geocoder geocoder = new Geocoder(this);
final String zip = "90210";
try {
  List<Address> addresses = geocoder.getFromLocationName(zipCode, 1);
  if (addresses != null && !addresses.isEmpty()) {
    Address address = addresses.get(0);
    // Use the address as needed
    String message = String.format("Latitude: %f, Longitude: %f", 
    address.getLatitude(), address.getLongitude());
    Toast.makeText(this, message, Toast.LENGTH_LONG).show();
  } else {
    // Display appropriate message when Geocoder services are not available
    Toast.makeToast(this, "Unable to geocode zipcode", Toast.LENGTH_LONG).show(); 
  }
} catch (IOException e) {
  // handle exception
}