PickList

package org.primefaces.showcase.view.data;

import org.primefaces.event.SelectEvent;
import org.primefaces.event.TransferEvent;
import org.primefaces.event.UnselectEvent;
import org.primefaces.model.DualListModel;
import org.primefaces.showcase.domain.Country;
import org.primefaces.showcase.service.CountryService;

import java.util.ArrayList;
import java.util.List;

import jakarta.annotation.PostConstruct;
import jakarta.enterprise.context.RequestScoped;
import jakarta.faces.application.FacesMessage;
import jakarta.faces.context.FacesContext;
import jakarta.inject.Inject;
import jakarta.inject.Named;

@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));
    }
}

package org.primefaces.showcase.service;

import org.primefaces.showcase.domain.Country;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import jakarta.annotation.PostConstruct;
import jakarta.enterprise.context.ApplicationScoped;
import jakarta.inject.Named;

@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("bn", "BD")));
        locales.add(CountryService.toCountry(new Locale("bs", "BA")));
        locales.add(CountryService.toCountry(new Locale("cs", "CZ")));
        locales.add(CountryService.toCountry(new Locale("el", "GR")));
        locales.add(CountryService.toCountry(new Locale("et", "EE")));
        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("is", "IS")));
        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("uz", "UZ")));
        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;
    }
}

package org.primefaces.showcase.domain;

import java.io.Serializable;
import java.util.Locale;
import java.util.Objects;

public class Country implements Serializable, Comparable<Country> {

    private int id;
    private String name;
    private String code;
    private Locale locale;
    private boolean rtl;

    public Country() {
    }

    public Country(int id, Locale locale) {
        this(id, locale.getDisplayCountry(), locale.getCountry().toLowerCase(), locale);
    }

    public Country(int id, Locale locale, boolean rtl) {
        this(id, locale.getDisplayCountry(), locale.getCountry().toLowerCase(), locale);
        this.rtl = rtl;
    }

    public Country(int id, String name, String code) {
        this(id, name, code, null);
    }

    public Country(int id, String name, String code, Locale locale) {
        this.id = id;
        this.name = name;
        this.code = code;
        this.locale = locale;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }

    public Locale getLocale() {
        return locale;
    }

    public void setLocale(Locale locale) {
        this.locale = locale;
    }

    public String getLanguage() {
        return locale == null ? "en" : locale.getLanguage();
    }

    public String getDisplayLanguage() {
        return locale == null ? "English" : locale.getDisplayLanguage();
    }

    public boolean isRtl() {
        return rtl;
    }

    public void setRtl(boolean rtl) {
        this.rtl = rtl;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        Country country = (Country) o;
        return id == country.id
                && Objects.equals(name, country.name)
                && Objects.equals(code, country.code);
    }

    @Override
    public int hashCode() {
        return Objects.hash(id, name, code);
    }

    @Override
    public String toString() {
        return name;
    }

    @Override
    public int compareTo(Country o) {
        return name.compareTo(o.name);
    }

}

package org.primefaces.showcase.convert;

import org.primefaces.showcase.domain.Country;
import org.primefaces.showcase.service.CountryService;

import jakarta.enterprise.context.ApplicationScoped;
import jakarta.faces.application.FacesMessage;
import jakarta.faces.component.UIComponent;
import jakarta.faces.context.FacesContext;
import jakarta.faces.convert.Converter;
import jakarta.faces.convert.ConverterException;
import jakarta.faces.convert.FacesConverter;
import jakarta.inject.Inject;
import jakarta.inject.Named;

@Named
@ApplicationScoped
@FacesConverter(value = "countryConverter", managed = true)
public class CountryConverter implements Converter<Country> {

    @Inject
    private CountryService countryService;

    @Override
    public Country getAsObject(FacesContext context, UIComponent component, String value) {
        if (value != null && !value.trim().isEmpty()) {
            try {
                return countryService.getCountriesAsMap().get(Integer.parseInt(value));
            }
            catch (NumberFormatException e) {
                throw new ConverterException(new FacesMessage(FacesMessage.SEVERITY_ERROR, "Conversion Error", "Not a valid country."));
            }
        }
        else {
            return null;
        }
    }

    @Override
    public String getAsString(FacesContext context, UIComponent component, Country value) {
        if (value != null) {
            return String.valueOf(value.getId());
        }
        else {
            return null;
        }
    }
}