JAVAFX - How convent numeric to string with locale rules

This example convent double value to String with locale rules (first US, second French, third English):

@FXML TextArea memo;

private void btnActionOnAction(ActionEvent event) {
  double iValue = 1234567.2345;
  String sText;
    
  sText = "US = " + 
    NumberFormat.getNumberInstance( Locale.US ).format( iValue ) + "\n";
  sText += "French = " + 
    NumberFormat.getNumberInstance( Locale.FRENCH ).format( iValue ) + "\n";         
  sText += "English = " + 
    NumberFormat.getNumberInstance( Locale.ENGLISH ).format( iValue ) + "\n";         
    
  memo.setText( sText );    
}

How you can see, US adds thousand separator:

US = 1,234,567.235
French = 1 234 567,235
English = 1,234,567.235