它加载stateList,但是当我更改状态的值时,它调用backbean但是addressBO为null。 我该如何解决?还有其他办法吗?
提前致谢。
<h:selectOneMenu id="stateList" value="#{newUserController.address.stateID}">
<f:selectItems value="#{addressController.stateList}" />
<f:valueChangeListener type="controller.address.AddressController"/>
<f:ajax event="change" render="cidadeList"/>
</h:selectOneMenu>
<h:selectOneMenu id="cityList" value="#{newUserController.address.cityID}">
<f:selectItems value="#{addressController.cityList}" />
</h:selectOneMenu>
BackBean
package controller.address;
@ManagedBean
@RequestScoped
public class AddressController implements ValueChangeListener {
@EJB
private AddressBO addressBO;
@PostConstruct
public void firstThingToDo() {
stateList = enderecoBO.loadStateListSelectItem();
}
@Override
public void processValueChange(ValueChangeEvent event) throws AbortProcessingException {
String state = (String) event.getNewValue();
cityList = addressBO.loadCityList(state);
}
}
设置了在这种情况下不显示的地址和用户值的另一个backbean。
package controller.user;
@ManagedBean
@RequestScoped
public class NewUserController {
private Address address;
private User user;
@EJB
private NewUserBO newUserBO;
public void registerNewUser() {
newUserBO.register(user, address);
}
public Address getAddress() {
return this.address;
}
public void setAddress(Address address) {
this.address = address;
}
public User getUser() {
return this.user;
}
public void setUser(User user) {
this.user = user;
}
}
答案 0 :(得分:1)
第一个问题是您在<f:valueChangeListener>
标记中创建了一个全新的类实例。这是不与@ManagedBean
引用的相同实例,并且也不会在此上调用托管bean相关注释。您更愿意在valueChangeListener="#{addressController.processValueChange}"
上使用<h:selectOneMenu>
。但这并不能立即解决所有问题。第二个列表的行为与预期不符,这一变化很大。
第二个问题是在 Validations 阶段调用了值更改侦听器方法。这是更改/加载模型值的错误时刻。您应该在调用操作阶段执行此操作。使用listener
的{{1}}属性。
所以:
<f:ajax>
与
<h:selectOneMenu id="stateList" value="#{newUserController.address.stateID}">
<f:selectItems value="#{addressController.stateList}" />
<f:ajax listener="#{addressController.changeState}" render="cidadeList" />
</h:selectOneMenu>