使用@OneToMany 关系加载 primefaces 拖曳动态 selectOneMenu

Question

我想加载两个 primefaces selectOneMenu 但只有一个 select 来自数据库。

Class 国家：

@Entity
@Table(name = "COUNTRY")
public class Country implements Serializable{


private static final long serialVersionUID = -2160543740997716714L;


@Id
@Column(name = "ID_COUNTRY")
private Long idTCountry;

@Column(name = "LIBELLE_COUNTRY")
private String libelleCountry;


@OneToMany(mappedBy="country")
  private List<City> Cities;

Class城市

@Entity
@Table(name = "CITY")
public class City implements Serializable{

private static final long serialVersionUID = -1617401771255693322L;

@Id
@Column(name = "ID_CITY")
private Long idCity;

@ManyToOne
@JoinColumn(name="COUNTRY")
private Country country;

@Column(name = "LIBELLE")
private String libelle;

我如何在 XHTML 中动态加载那些 selectOneMenu？

我这样做了，但没有用：

        <p:outputLabel for="country" value="Country: " />
        <p:selectOneMenu id="country" value="#{countryView.selectedCountry}"  style="width:150px">
            <p:ajax listener="#{countryView.onTypeChange}" update="city" />
            <f:selectItems value="#{countryView.countries}" itemLabel="#{selectedType.libelleCountry}" var="selectedCountry" />
        </p:selectOneMenu>

        <p:outputLabel for="city" value="City: " />
        <p:selectOneMenu id="city" value="#{countryView.selectedCity}" style="width:150px">
            <f:selectItems value="#{countryView.selectedCountry.cities}" itemLabel="#{selectedCity.libelle}" var="selectedCity" itemValue="#{selectedCity}"/>
        </p:selectOneMenu>

谁能帮我做这个吗？

Answer 1

是的，拉斐尔罗斯我必须这样做：

@OneToMany(fetch = FetchType.EAGER, mappedBy="country", cascade =    CascadeType.ALL)
private List<City> cities;

当然我还必须添加转换器：

    <p:outputLabel for="city" value="City: " />
    <p:selectOneMenu id="city" value="#{countryView.selectedCity}" style="width:150px"  converter="#{cityConverter}">
        <f:selectItems value="#{countryView.selectedCountry.cities}" itemLabel="#{selectedCity.libelle}" var="selectedCity" itemValue="#{selectedCity}"/>
    </p:selectOneMenu>

如你所见，我在 ajax 事件中不需要监听器：

 <p:ajax update="city" />

使用@OneToMany 关系加载 primefaces 拖曳动态 selectOneMenu

Load primefaces tow dynamic selectOneMenu with @OneToMany relation

jsf

jpa

primefaces

one-to-many

selectonemenu