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;

    @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);
    }

    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 void onItemUnselect(UnselectEvent event) {
        FacesContext context = FacesContext.getCurrentInstance();

        FacesMessage msg = new FacesMessage();
        msg.setSummary("Item unselected: " + event.getObject().toString());
        msg.setSeverity(FacesMessage.SEVERITY_INFO);

        context.addMessage(null, msg);
    }
}