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正如您在屏幕截图中看到的，我对属性“member.city”有一个JSF 隐式值验证错误。目的是-通过ajax-在上一个Country Select one menu上选择一个国家后填充city select One Menu。这是通过使用selectOneMenu 更改侦听器和ajax来更新显示城市列表的组件来实现的。但是，我收到验证错误，并且未提交表单。

验证错误截图

我尝试使用和不使用（hascode 和 equals 方法）的实体，但徒劳无功。我使用了一个单独的 Managed Bean ViewScoped来检索过滤后的列表，但徒劳无功。**

如果我用检索所有城市的列表替换过滤的城市列表（在 xhtml 表单中，替换<f:selectItems value="#{cityBean.citiesByCountry}" />为<f:selectItems value="#{cityBean.all}" />，则没有验证错误并且表单成功提交。

** 这里是代码：

形式：

<p:outputLabel for="country" value="#{i18n.country}" />
                    <p:selectOneMenu valueChangeListener="#{cityBean.selectCountry}" rendered="true" id="country" value="#{newMember.country}" converter="#{countryBean.converter}" 
                        style="width:160px;text-align:left;border:thin solid gray;"
                        required="true" requiredMessage="#{i18n.required}">                     
                        <f:selectItems value="#{countryBean.all}" var="countryname" itemLabel="#{countryname.name}"/>
                        <p:ajax event="change" update="city" />
                    </p:selectOneMenu>
                    <p:message for="country" />

                    <p:outputLabel for="city" value="#{i18n.city}" />
                    <p:selectOneMenu rendered="true" id="city" value="#{newMember.city}" converter="#{cityBean.converter}" converterMessage="Conversion error!"
                        style="width:160px;text-align:left;border:thin solid gray;"
                        required="true" requiredMessage="#{i18n.required}">                                         
                        <f:selectItems value="#{cityBean.citiesByCountry}" var="cityname" itemLabel="#{cityname.cityname}"/>                        
                    </p:selectOneMenu>
                    <p:message for="city" />

市实体负责人：

@XmlRootElement
@Entity
@Table(name = "city", schema = "public")
@NamedQueries({
        @NamedQuery(name = "City.findAll", query = "SELECT c FROM City c"),
        @NamedQuery(name = "City.findById", query = "SELECT c FROM City c WHERE c.id = :id"),
        @NamedQuery(name = "City.findByCountry", query = "SELECT c FROM City c WHERE c.country = :country"),
        @NamedQuery(name = "City.findByCountryOrderedByName", query = "SELECT c FROM City c WHERE c.country = :country ORDER BY c.cityname ASC") })
@NamedNativeQueries({ @NamedNativeQuery(name = "City.findCountryNativeSQL", query = "select * from city c where c.countrybeta = :country.betacode", resultClass = City.class) })
public class City implements java.io.Serializable {

    private static final long serialVersionUID = 3364735938266980295L;
    private int id;
    private Integer version;
    private Country country;
    private String cityname;
    private String district;
    private int population;
    private Set<Member> members = new HashSet<Member>(0);

    public City() {
    }
// ...remainder of entity code (contructors and fields..)

豆子：

@Named
@Stateful
@ConversationScoped
public class CityBean implements Serializable {

    private static final long serialVersionUID = 1L;
    private City city;
    private List<City> cityList;

    public City getCity() {
        return this.city;
    }

    private Country selectedCountry;

    @Inject
    private Conversation conversation;

    @PersistenceContext(type = PersistenceContextType.EXTENDED)
    private EntityManager entityManager;
// remainder of code....

// The List that works fine with Select one Menu
public List<City> getAll() {

        CriteriaQuery<City> criteria = this.entityManager.getCriteriaBuilder()
                .createQuery(City.class);
        return this.entityManager.createQuery(
                criteria.select(criteria.from(City.class))).getResultList();
    }

    @PostConstruct
    public void init() {
        setCityList(getCitiesByCountry());
    }

    public List<City> getCityList() {
        return cityList;
    }

    public void setCityList(List<City> cityList) {
        this.cityList = cityList;
    }

    /**
     * The List That triggers a jsf value validation error
     * @return List of Cities by Country ordered by city name
     */
    public List<City> getCitiesByCountry() {
        TypedQuery<City> query = this.entityManager.createNamedQuery(
                "City.findByCountryOrderedByName", City.class);
        query.setParameter("country", selectedCountry);
        return query.getResultList();
    }

    // The Select One Menu Listener
    public void selectCountry(ValueChangeEvent event) {

        if (event != null) {
            selectedCountry = (Country) event.getNewValue();
        }
        }

        // getters and setters....

环境： - JSF 21 - 休眠 - JBoss AS 7.1 - PrimeFaces 3.5 - Linux 3.5 / Firefox 18.0.2

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1 回答 1

4

您的具体问题是因为您没有开始对话@PostConstruct，因此 bean 的行为类似于请求范围。这样，城市列表将在处理表单提交期间发生不兼容的变化并变为空（因此在可用项目列表中找不到所选项目，因此出现此验证错误）。

您需要在@PostConstruct.

conversation.begin();

也可以看看：

与具体问题无关valueChangeListener，在 getter 方法中使用和执行业务逻辑是错误的方法。您根本不应该在 getter 方法中执行业务逻辑。这显然是低效的。它们应该只返回已经准备好的 bean 属性。

重写你的逻辑如下：

<p:selectOneMenu value="#{bean.country}" ...>
    <f:selectItems value="#{bean.countries}" />
    <p:ajax listener="#{bean.updateCities}" update="city" />
</p:selectOneMenu>

<p:selectOneMenu id="city" value="#{bean.city}" ...>                                         
    <f:selectItems value="#{bean.cities}" />
</p:selectOneMenu>

和

private Country country;
private List<Country> countries;
private City city;
private List<City> cities;

@PostConstruct
public void init() {
    countries = service.listCountries();

public void updateCities() {
    cities = service.listCities(country);
}

// Add/generate normal!! getters/setters.

也可以看看：

于 2013-02-15T16:56:47.797 回答