class JaxbLocaleAdapter extends XmlAdapter<String, Locale> {

    @Override
    public Locale unmarshal(String localeString) {
        if (localeString == null) {
            return null;
        }
        return new Locale(localeString);
    }

    @Override
    public String marshal(Locale locale) {<FILL_FUNCTION_BODY>}
}

        if (locale == null) {
            return null;
        }
        return locale.toString();
    
<no_super_class>