Set a default Locale
import java.text.DecimalFormat; import java.text.NumberFormat; import java.util.Locale; public class Main { public static void main(String[] args) { NumberFormat formatter = new DecimalFormat(); Locale locale = Locale.getDefault(); System.out.println("Locale = " + locale); System.out.println(formatter.format(123.123)); locale = Locale.ITALY; Locale.setDefault(locale); formatter = new DecimalFormat(); System.out.println("Locale = " + locale); System.out.println(formatter.format(123.123)); } }