SelectManyCheckbox

@Named
@RequestScoped
public class CheckboxView {

    private String[] selectedOptions;
    private String[] selectedOptions2;
    private String[] selectedCities;
    private String[] selectedCities2;
    private List<String> cities;
    private List<SelectItem> countries;
    private String[] selectedCountries;
    private List<Country> countries2;
    private List<Country> selectedCountries2;
    private List<SelectItem> countries3;
    private List<Country> selectedCountries3;

    @Inject
    private CountryService service;

    @PostConstruct
    public void init() {
        cities = new ArrayList<>();
        cities.add("Miami");
        cities.add("London");
        cities.add("Paris");
        cities.add("Istanbul");
        cities.add("Berlin");
        cities.add("Barcelona");
        cities.add("Rome");
        cities.add("Brasilia");
        cities.add("Amsterdam");

        countries = new ArrayList<>();
        SelectItemGroup europeCountries = new SelectItemGroup("European Countries");
        europeCountries.setSelectItems(new SelectItem[]{
            new SelectItem("Germany", "Germany"),
            new SelectItem("Turkey", "Turkey"),
            new SelectItem("Spain", "Spain")
        });

        SelectItemGroup americaCountries = new SelectItemGroup("American Countries");
        americaCountries.setSelectItems(new SelectItem[]{
            new SelectItem("United States", "United States"),
            new SelectItem("Brazil", "Brazil"),
            new SelectItem("Mexico", "Mexico")
        });

        countries.add(europeCountries);
        countries.add(americaCountries);

        countries2 = service.getCountries();

        countries3 = new ArrayList<>();

        SelectItemGroup europeCountries3 = new SelectItemGroup("European Countries");
        europeCountries3.setSelectItems(isoCodesToSelectItemArray("DE", "TR", "ES"));

        SelectItemGroup americaCountries3 = new SelectItemGroup("American Countries");
        americaCountries3.setSelectItems(isoCodesToSelectItemArray("US", "BR", "MX"));

        countries3.add(europeCountries3);
        countries3.add(americaCountries3);
    }

    public String[] getSelectedOptions() {
        return selectedOptions;
    }

    public void setSelectedOptions(String[] selectedOptions) {
        this.selectedOptions = selectedOptions;
    }

    public String[] getSelectedOptions2() {
        return selectedOptions2;
    }

    public void setSelectedOptions2(String[] selectedOptions2) {
        this.selectedOptions2 = selectedOptions2;
    }

    public String[] getSelectedCities() {
        return selectedCities;
    }

    public void setSelectedCities(String[] selectedCities) {
        this.selectedCities = selectedCities;
    }

    public String[] getSelectedCities2() {
        return selectedCities2;
    }

    public void setSelectedCities2(String[] selectedCities2) {
        this.selectedCities2 = selectedCities2;
    }

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

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

    public List<SelectItem> getCountries() {
        return countries;
    }

    public void setCountries(List<SelectItem> countries) {
        this.countries = countries;
    }

    public String[] getSelectedCountries() {
        return selectedCountries;
    }

    public void setSelectedCountries(String[] selectedCountries) {
        this.selectedCountries = selectedCountries;
    }

    public List<Country> getCountries2() {
        return countries2;
    }

    public void setCountries2(List<Country> countries2) {
        this.countries2 = countries2;
    }

    public List<Country> getSelectedCountries2() {
        return selectedCountries2;
    }

    public void setSelectedCountries2(List<Country> selectedCountries2) {
        this.selectedCountries2 = selectedCountries2;
    }

    public List<SelectItem> getCountries3() {
        return countries3;
    }

    public void setCountries3(List<SelectItem> countries3) {
        this.countries3 = countries3;
    }

    public List<Country> getSelectedCountries3() {
        return selectedCountries3;
    }

    public void setSelectedCountries3(List<Country> selectedCountries3) {
        this.selectedCountries3 = selectedCountries3;
    }

    public void onItemUnselect(UnselectEvent event) {
        FacesMessage msg = new FacesMessage();
        msg.setSummary("Item unselected: " + event.getObject().toString());
        msg.setSeverity(FacesMessage.SEVERITY_INFO);

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

    public void selectedOptionsChanged() {
        String message = "selectedOptions changed to: ";
        if (selectedOptions != null) {
            for (int i = 0; i < selectedOptions.length; i++) {
                if (i > 0) {
                    message += ", ";
                }
                message += selectedOptions[i];
            }
        }

        FacesContext.getCurrentInstance().addMessage(null,
                new FacesMessage(FacesMessage.SEVERITY_INFO, message, null));
    }

    public void selectedOptions2Changed() {
        String message = "selectedOptions2 changed to: ";
        if (selectedOptions2 != null) {
            for (int i = 0; i < selectedOptions2.length; i++) {
                if (i > 0) {
                    message += ", ";
                }
                message += selectedOptions2[i];
            }
        }

        FacesContext.getCurrentInstance().addMessage(null,
                new FacesMessage(FacesMessage.SEVERITY_INFO, message, null));
    }

    private SelectItem[] isoCodesToSelectItemArray(String... isoCodes) {
        return CountryService.toCountryStream(isoCodes)
                .map(country -> new SelectItem(country, country.getName()))
                .toArray(SelectItem[]::new);
    }
}

@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.FRANCE));
        locales.add(CountryService.toCountry(Locale.GERMANY));
        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("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("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("iw", "IL"), true));
        locales.add(CountryService.toCountry(new Locale("ka", "GE")));
        locales.add(CountryService.toCountry(new Locale("lt", "LT")));
        locales.add(CountryService.toCountry(new Locale("lv", "LV")));
        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", "RS")));
        locales.add(CountryService.toCountry(new Locale("sv", "SE")));
        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;
    }
}