Question

在我的帖子（Hibernate Primefaces AutoComplete text）之后，我稍微切换了实现。但现在我遇到了一个问题。

即使我使用AJAX事件，我也不会保留选定的值以填充第二个下拉列表。

我的CREATE.XHTML

<h:head></h:head>
<ui:debug rendered="true"/>
    <body>
        <h:form id="createAddressForm" prependId="true">
            <!-- <p:messages autoUpdate="true" /> -->
            <p:growl id="msgs" showDetail="true" />

            <h:panelGrid columns="2" style="margin-bottom:10px" cellpadding="5">
                <p:outputLabel for="countryDropDown" value="Country" />
                <p:selectOneMenu id="countryDropDown" value="#{addressController.selectedIsoCountry}" >
                    <p:ajax listener="#{addressController.onCountryChange}" update="stateDropDown" />
                    <f:selectItem itemValue="" itemLabel="Select a country"/>
                    <f:selectItems value="#{addressController.countryMap}" />
                </p:selectOneMenu>

                <p:outputLabel for="stateDropDown" value="State" />
                <p:selectOneMenu id="stateDropDown" value="#{addressController.state}" >
                    <f:selectItem itemValue="" itemLabel="Selecione a State" />
                    <f:selectItems value="#{addressController.stateMap}" />
                </p:selectOneMenu>              
            </h:panelGrid>
        </h:form>
    </body>
</html>

这是AddressController.java

import java.util.Map;
import java.util.TreeMap;

import javax.annotation.PostConstruct;
import javax.ejb.EJB;
import javax.faces.bean.SessionScoped;
import javax.inject.Named;

import br.com.azulseguros.ejb.CountryEJB;
import br.com.azulseguros.entity.Country;
import br.com.azulseguros.entity.State;

@SessionScoped
@Named
public class AddressController {
    @EJB
    private CountryEJB countryEJB;

    private String selectedIsoCountry = null;

    private State state = null;

    private Map<String, String> countryMap = null;

    private Map<String, String> stateMap = null;

    @PostConstruct
    private void init() {
        Map<String, String> retorno = new TreeMap<String, String>();
        for (Country _tmp : countryEJB.findAll()) {
            retorno.put(_tmp.getName(), _tmp.getIso());
        }
        countryMap = retorno;
    }

    public Map<String, String> getCountryMap() {
        return countryMap;
    }

    public Map<String, String> getStateMap() {
        return stateMap;
    }

    public String getSelectedIsoCountry() {
        return selectedIsoCountry;
    }

    public State getState() {
        return state;
    }

    public void setSelectedIsoCountry(String selectedIsoCountry) {
        this.selectedIsoCountry = selectedIsoCountry;
    }

    public void setState(State state) {
        this.state = state;
    }

    public void setCountryMap(Map<String, String> countryMap) {
        this.countryMap = countryMap;
    }

    public void setStateMap(Map<String, String> stateMap) {
        this.stateMap = stateMap;
    }

    public void onCountryChange() {
        setStateMap(getStatesFromSelectedCountry());
    }

    private Map<String, String> getStatesFromSelectedCountry() {
        Map<String, String> retorno = new TreeMap<String, String>();
        if (selectedIsoCountry != null && !selectedIsoCountry.equals("")) {
            for (State _tmp : countryEJB.findByIso(selectedIsoCountry).getStates()) {
                retorno.put(_tmp.getName(), _tmp.getFu());
            }
        }
        return retorno;
    }
}

用于查找所有国家/地区的EJB负责人工作正常。这有很多问题，我不知道如何解决它。 1 - 我第一次调用页面后，它调用init方法10次; 2 - 之后它引发了方法getStatesFromSelectedCountry，甚至没有从第一个下拉列表中选择任何国家，然后再次唤起init方法; 3 - 当我选择一个国家时，它会唤起init方法的7倍，然后是getStatesFromSelectedCountry（），但selectedIsoCountry是null。

Answer 1

bean的init方法被多次调用，因为您已将bean定义为使用javax.inject.Named的CDI bean，没有范围，以及使用javax.faces.bean.SessionScoped作为JSF Managed Bean;如果您打算使用CDI bean，只需将后一个注释替换为javax.enterprise.context.SessionScoped即可。见Why are there different bean management annotations

从CDI的角度来看，bean默认为RequestScoped，这也应该解释您遇到的第二个问题。

关于第三个问题，请参阅此问答：

OneMenu没有坚持改变价值

1 个答案: