PickList

@Named
@RequestScoped
public class PickListView {

    @Inject
    private CountryService service;

    private DualListModel<String> cities;
    private DualListModel<Country> countries;

    @PostConstruct
    public void init() {
        //Cities
        List<String> citiesSource = new ArrayList<>();
        List<String> citiesTarget = new ArrayList<>();

        citiesSource.add("San Francisco");
        citiesSource.add("London");
        citiesSource.add("Paris");
        citiesSource.add("Istanbul");
        citiesSource.add("Berlin");
        citiesSource.add("Barcelona");
        citiesSource.add("Rome");

        cities = new DualListModel<>(citiesSource, citiesTarget);

        //Countries
        List<Country> countriesSource = service.getCountries().subList(0, 10);
        List<Country> countriesTarget = new ArrayList<>();

        countries = new DualListModel<>(countriesSource, countriesTarget);

    }

    public DualListModel<String> getCities() {
        return cities;
    }

    public void setCities(DualListModel<String> cities) {
        this.cities = cities;
    }

    public CountryService getService() {
        return service;
    }

    public void setService(CountryService service) {
        this.service = service;
    }

    public DualListModel<Country> getCountries() {
        return countries;
    }

    public void setCountries(DualListModel<Country> countries) {
        this.countries = countries;
    }

    public void onTransfer(TransferEvent event) {
        StringBuilder builder = new StringBuilder();
        for (Object item : event.getItems()) {
            builder.append(((Country) item).getName()).append("<br />");
        }

        FacesMessage msg = new FacesMessage();
        msg.setSeverity(FacesMessage.SEVERITY_INFO);
        msg.setSummary("Items Transferred");
        msg.setDetail(builder.toString());

        FacesContext.getCurrentInstance().addMessage(null, msg);
    }

    public void onSelect(SelectEvent<Country> event) {
        FacesContext context = FacesContext.getCurrentInstance();
        context.addMessage(null, new FacesMessage(FacesMessage.SEVERITY_INFO, "Item Selected", event.getObject().getName()));
    }

    public void onUnselect(UnselectEvent<Country> event) {
        FacesContext context = FacesContext.getCurrentInstance();
        context.addMessage(null, new FacesMessage(FacesMessage.SEVERITY_INFO, "Item Unselected", event.getObject().getName()));
    }

    public void onReorder() {
        FacesContext context = FacesContext.getCurrentInstance();
        context.addMessage(null, new FacesMessage(FacesMessage.SEVERITY_INFO, "List Reordered", null));
    }
}

@Named
@ApplicationScoped
public class CountryService {

    private List<Country> countries;
    private Map<Integer, Country> countriesAsMap;
    private List<Country> locales;
    private Map<Integer, Country> localesAsMap;

    public static Stream<Country> toCountryStream(String... isoCodes) {
        return Stream.of(isoCodes)
                .map(isoCode -> new Locale("", isoCode))
                .map(CountryService::toCountry);
    }

    public static Country toCountry(Locale locale) {
        return CountryService.toCountry(locale, false);
    }

    public static Country toCountry(Locale locale, boolean rtl) {
        //use hash code from locale to have a reproducible ID (required for CountryConverter)
        return new Country(locale.hashCode(), locale, rtl);
    }

    @PostConstruct
    public void init() {
        countries = CountryService.toCountryStream(Locale.getISOCountries())
                .sorted(Comparator.comparing(Country::getName))
                .collect(Collectors.toList());

        locales = new ArrayList<>();

        locales.add(CountryService.toCountry(Locale.US));
        locales.add(CountryService.toCountry(Locale.UK));
        locales.add(CountryService.toCountry(new Locale("en", "AU")));
        locales.add(CountryService.toCountry(Locale.FRANCE));
        locales.add(CountryService.toCountry(Locale.GERMANY));
        locales.add(CountryService.toCountry(new Locale("de", "AT")));
        locales.add(CountryService.toCountry(new Locale("de", "CH")));
        locales.add(CountryService.toCountry(Locale.ITALY));
        locales.add(CountryService.toCountry(Locale.KOREA));
        locales.add(CountryService.toCountry(new Locale("es", "ES")));
        locales.add(CountryService.toCountry(new Locale("ca", "ES")));
        locales.add(CountryService.toCountry(new Locale("nl", "NL")));
        locales.add(CountryService.toCountry(new Locale("pt", "BR")));
        locales.add(CountryService.toCountry(new Locale("pt", "PT")));
        locales.add(CountryService.toCountry(new Locale("ar", "SA"), true));
        locales.add(CountryService.toCountry(new Locale("ar", "TN"), true));
        locales.add(CountryService.toCountry(new Locale("bg", "BG")));
        locales.add(CountryService.toCountry(new Locale("cs", "CZ")));
        locales.add(CountryService.toCountry(new Locale("el", "GR")));
        locales.add(CountryService.toCountry(new Locale("fa", "IR"), true));
        locales.add(CountryService.toCountry(new Locale("fi", "FI")));
        locales.add(CountryService.toCountry(new Locale("da", "DK")));
        locales.add(CountryService.toCountry(new Locale("hi", "IN")));
        locales.add(CountryService.toCountry(new Locale("in", "ID")));
        locales.add(CountryService.toCountry(new Locale("hr", "HR")));
        locales.add(CountryService.toCountry(new Locale("ja", "JP")));
        locales.add(CountryService.toCountry(new Locale("hu", "HU")));
        locales.add(CountryService.toCountry(new Locale("he", "IL"), true));
        locales.add(CountryService.toCountry(new Locale("ka", "GE")));
        locales.add(CountryService.toCountry(new Locale("ckb", "IQ"), true));
        locales.add(CountryService.toCountry(new Locale("km", "KH")));
        locales.add(CountryService.toCountry(new Locale("ky", "KG")));
        locales.add(CountryService.toCountry(new Locale("kk", "KZ")));
        locales.add(CountryService.toCountry(new Locale("lt", "LT")));
        locales.add(CountryService.toCountry(new Locale("lv", "LV")));
        locales.add(CountryService.toCountry(new Locale("ms", "MY")));
        locales.add(CountryService.toCountry(new Locale("no", "NO")));
        locales.add(CountryService.toCountry(new Locale("pl", "PL")));
        locales.add(CountryService.toCountry(new Locale("ro", "RO")));
        locales.add(CountryService.toCountry(new Locale("ru", "RU")));
        locales.add(CountryService.toCountry(new Locale("sk", "SK")));
        locales.add(CountryService.toCountry(new Locale("sl", "SI")));
        locales.add(CountryService.toCountry(new Locale("sr", "BA")));
        locales.add(CountryService.toCountry(new Locale("sr", "RS")));
        locales.add(CountryService.toCountry(new Locale("sv", "SE")));
        locales.add(CountryService.toCountry(new Locale("th", "TH")));
        locales.add(CountryService.toCountry(new Locale("tr", "TR")));
        locales.add(CountryService.toCountry(new Locale("uk", "UA")));
        locales.add(CountryService.toCountry(new Locale("vi", "VN")));
        locales.add(CountryService.toCountry(Locale.SIMPLIFIED_CHINESE));
        locales.add(CountryService.toCountry(Locale.TRADITIONAL_CHINESE));
    }

    public List<Country> getCountries() {
        return new ArrayList<>(countries);
    }

    public Map<Integer, Country> getCountriesAsMap() {
        if (countriesAsMap == null) {
            countriesAsMap = getCountries().stream().collect(Collectors.toMap(Country::getId, country -> country));
        }
        return countriesAsMap;
    }

    public List<Country> getLocales() {
        return new ArrayList<>(locales);
    }

    public Map<Integer, Country> getLocalesAsMap() {
        if (localesAsMap == null) {
            localesAsMap = getLocales().stream().collect(Collectors.toMap(Country::getId, country -> country));
        }
        return localesAsMap;
    }
}