You just need to convert your -
JTextField deg;
to
NumberFormat numberFormat = NumberFormat.getNumberInstance(Locale.getDefault());
DecimalFormat decimalFormat = (DecimalFormat) numberFormat;
decimalFormat.setGroupingUsed(false);
deg = new JFormattedTextField(decimalFormat);
deg.setColumns(15); //whatever size you wish to set
This will return a general-purpose number format for the current default locale.
Thanks