我正在尝试使用 @viewScoped 初始化 bean 中的属性，但它不起作用

Question

大家好，我正在尝试使用两个oneMenu 构建一个网页，第二个取决于第二个。我的 XHTML 文件和我的 bean 都在下面。 当我尝试创建一个新的“structureAttache”时，我遇到了以下问题

TemplateStructureAttache.xhtml @40,139 value="#{structureBean.structureAttache.intituleStructure}": Target Unreachable, 'structureAttache' returned null

当我使用方法initStruc 创建一个新的structureAttache 然后我在我的第一个ajax 的侦听器中调用它时，我成功创建了一个structureAttache 但是当我第二次这样做时，它似乎该值已经在数据库中退出，它拒绝请帮我解决这个问题

/*
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package com.dresen.dresen.Beans;

import com.dresen.dresen.ServiceInterface.IArrondissementService;
import com.dresen.dresen.ServiceInterface.IStructureService;
import com.dresen.dresen.entities.Arrondissement;
import com.dresen.dresen.entities.StructureAttache;
import com.dresen.dresen.entities.CategorieStructure;
import java.util.List;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ManagedProperty;
import com.dresen.dresen.ServiceInterface.ICategorieStructureService;
import com.dresen.dresen.ServiceInterface.IDepartementService;
import com.dresen.dresen.entities.Departement;
import java.io.Serializable;
import javax.annotation.PostConstruct;
import javax.faces.bean.ViewScoped;

/**
 *
 * @author Vivien Saa
 */
@ManagedBean
@ViewScoped
public class StructureBean implements Serializable{
    @ManagedProperty(value = "#{IStructureService}")
    private IStructureService iStructureService;

    @ManagedProperty(value = "#{IArrondissementService}")
    private IArrondissementService iArrondissementService;

    @ManagedProperty(value = "#{ICategorieStructureService}")
    private ICategorieStructureService iCategorieStructureService;

    @ManagedProperty(value  ="#{IDepartementService}")
    private IDepartementService iDepartementService;


    private long idDepartement;
    private long idArrondissement;
    private long idCategorieStructure;
    private StructureAttache structureAttache;
    private List<Arrondissement> listArrondissement;
    private List<Departement> listDepartement;
    private List<CategorieStructure> listCategorieStructure;
    private Arrondissement arrondissement = new Arrondissement();
    private CategorieStructure CategorieStructure = new CategorieStructure();



    public StructureBean() {
        structureAttache = new StructureAttache();
        idDepartement = 0L;
        idArrondissement = 0L;
        idCategorieStructure = 0L;
    }

    public ICategorieStructureService getiCategorieStructureService() {
        return iCategorieStructureService;
    }

    public void setiCategorieStructureService(ICategorieStructureService iCategorieStructureService) {
        this.iCategorieStructureService = iCategorieStructureService;
    }

    public long getIdDepartement() {
        return idDepartement;
    }

    public void setIdDepartement(long idDepartement) {
        this.idDepartement = idDepartement;
    }

    public IDepartementService getiDepartementService() {
        return iDepartementService;
    }

    public void setiDepartementService(IDepartementService iDepartementService) {
        this.iDepartementService = iDepartementService;
    }

    public List<Departement> getListDepartement() {
        return iDepartementService.findAllDepartement();
    }

    public void setListDepartement(List<Departement> listDepartement) {
        this.listDepartement = listDepartement;
    }



    public long getIdCategorieStructure() {
        return idCategorieStructure;
    }

    public void setIdCategorieStructure(long idCategorieStructure) {
        this.idCategorieStructure = idCategorieStructure;
    }

    public List<CategorieStructure> getListCategorieStructure() {
        return iCategorieStructureService.findAllCategorieStructure();
    }

    public void setListCategorieStructure(List<CategorieStructure> listCategorieStructure) {
        this.listCategorieStructure = listCategorieStructure;
    }



    public IStructureService getiStructureService() {
        return iStructureService;
    }

    public void setiStructureService(IStructureService iStructureService) {
        this.iStructureService = iStructureService;
    }

    public IArrondissementService getiArrondissementService() {
        return iArrondissementService;
    }

    public void setiArrondissementService(IArrondissementService iArrondissementService) {
        this.iArrondissementService = iArrondissementService;
    }

    public long getIdArrondissement() {
        return idArrondissement;
    }

    public void setIdArrondissement(long idArrondissement) {
        this.idArrondissement = idArrondissement;
    }

    public StructureAttache getStructureAttache() {
        return structureAttache;
    }

    public void setStructureAttache(StructureAttache structureAttache) {
        this.structureAttache = structureAttache;
    }

    public List<Arrondissement> getListArrondissement() {
        return iArrondissementService.findArrondissementByIdDepart(idDepartement);
    }

    public void setListArrondissement(List<Arrondissement> listArrondissement) {
        this.listArrondissement = listArrondissement;
    }

    public Arrondissement getArrondissement() {
        return arrondissement;
    }

    public void setArrondissement(Arrondissement arrondissement) {
        this.arrondissement = arrondissement;
    }

    public CategorieStructure getCategorieStructure() {
        return CategorieStructure;
    }

    public void setCategorieStructure(CategorieStructure CategorieStructure) {
        this.CategorieStructure = CategorieStructure;
    }
    public void initStruc() {
        structureAttache = new StructureAttache();
    }

    public StructureAttache createStructure(){
        System.out.println("vvsssssssssvsssssssssssssssssssssssvv why don't you work");
        arrondissement = iArrondissementService.findArrondissementById(idArrondissement);
        CategorieStructure = iCategorieStructureService.findCategorieStructureById(idCategorieStructure);
        structureAttache.setCategorieStructure(CategorieStructure);
        structureAttache.setArrondissement(arrondissement);
        return iStructureService.createStructureAttache(structureAttache);
    }
    public StructureAttache findStructureById(){
        return iStructureService.findStructureAttacheById(structureAttache.getId());
    } 
    public StructureAttache updateStructure(){
        arrondissement = iArrondissementService.findArrondissementById(idArrondissement);
        CategorieStructure = iCategorieStructureService.findCategorieStructureById(idCategorieStructure);
        structureAttache.setCategorieStructure(CategorieStructure);
        structureAttache.setArrondissement(arrondissement);
        return iStructureService.updateStructureAttache(structureAttache);
    }
    public List<StructureAttache> findAllStructure(){
        return iStructureService.findAllStructureAttache();
    } 
}

<?xml version="1.0" encoding="UTF-8"?>
<!--
To change this license header, choose License Headers in Project Properties.
To change this template file, choose Tools | Templates
and open the template in the editor.
-->
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://java.sun.com/jsf/html"
      xmlns:f="http://java.sun.com/jsf/core"
      xmlns:p="http://primefaces.org/ui"
      xmlns:ui="http://java.sun.com/jsf/facelets">
    <h:head>
        <title>Application de gestion du personnel des services déconcentrés du MINESEC EXTREME NORD</title>
        <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
    </h:head>
     <h:body> 
        <div id="menu">
            <ui:include src="Menu.xhtml"/>
        </div>
         <f:view>
            <p:dialog widgetVar="dlg" header=" Enregistrer une nouvel nouvelle Structure d'attache " hideEffect="explode" showEffect="explode" modal="true">
                <h:form id="formAjouter" >
                     <p:panelGrid id="panelAjouter" columns="2">
                                <p:outputLabel value="Département:" />       
                                <p:selectOneMenu id="depart" value="#{structureBean.idDepartement}"  label="programme"  filter="true" filterMatchMode="startsWith" panelStyle="width:220px">
                                    <p:ajax  event="change" update="arrond" />
                                    <f:selectItem itemLabel="Selectioner le département" itemValue="" noSelectionOption="true" />
                                    <f:selectItems var="custe1" value="#{structureBean.listDepartement}"   itemLabel="#{custe1.intituleDepartement}" itemValue="#{custe1.id}" itemLabelEscaped="true" />
                                </p:selectOneMenu>
                                <p:outputLabel value="Arrondissement:" />       
                                <p:selectOneMenu id="arrond" value="#{structureBean.idArrondissement}" filter="true" filterMatchMode="startsWith" panelStyle="width:220px">
                                    <f:selectItems var="custe2" value="#{structureBean.listArrondissement}"   itemLabel="#{custe2.intituleArrondissement}" itemValue="#{custe2.id}" itemLabelEscaped="true" />
                                </p:selectOneMenu>
                                 <p:outputLabel value="Categorie de Structure:" />       
                                 <p:selectOneMenu  value="#{structureBean.idCategorieStructure}" filter="true" filterMatchMode="startsWith" panelStyle="width:220px">
                                     <f:selectItems var="custe3" value="#{structureBean.listCategorieStructure}"   itemLabel="#{custe3.intituleCategorieStructure}" itemValue="#{custe3.id}" itemLabelEscaped="true" />
                                </p:selectOneMenu>
                                <p:outputLabel value="Intitule :" for="intitule" />
                                <p:inputText id="intitule" value="#{structureBean.structureAttache.intituleStructure}" title="intitulé" />
                                <p:outputLabel value="Code/Abréviation :" for="abrev" />
                                <p:inputText id="abrev" value="#{structureBean.structureAttache.codeStructure}" title="abrev"/>
                                <p:commandButton value="Enregistrer" action="#{structureBean.createStructure()}"  oncomplete="PF('dlg').hide()" update=":tableForm:table" id="bout1" ajax="false" />
                    </p:panelGrid>


                </h:form>
            </p:dialog>
            <p:dialog widgetVar="dl" header=" Modifier une structure d'attache" hideEffect="fold" showEffect="explode" resizable="true">
                <h:form id="formModifier" enctype="multipart/form-data">                
                    <p:panelGrid id="panelGModifier" columns="2">
                                <p:outputLabel value="Département:" />       
                                <p:selectOneMenu id="depart" value="#{structureBean.idDepartement}"  label="programme"  filter="true" filterMatchMode="startsWith" panelStyle="width:220px">
                                    <p:ajax  event="change" update="arrond" />
                                    <f:selectItem itemLabel="Selectioner le département" itemValue="" noSelectionOption="true" />
                                    <f:selectItems var="custe1" value="#{structureBean.listDepartement}"   itemLabel="#{custe1.intituleDepartement}" itemValue="#{custe1.id}" itemLabelEscaped="true" />
                                </p:selectOneMenu>
                                <p:outputLabel value="Arrondissement:" />       
                                <p:selectOneMenu id="arrond" value="#{structureBean.idArrondissement}" filter="true" filterMatchMode="startsWith" panelStyle="width:220px">
                                    <f:selectItems var="custe2" value="#{structureBean.listArrondissement}"   itemLabel="#{custe2.intituleArrondissement}" itemValue="#{custe2.id}" itemLabelEscaped="true" />
                                </p:selectOneMenu>
                                 <p:outputLabel value="Categorie de Structure:" />       
                                 <p:selectOneMenu  value="#{structureBean.idCategorieStructure}" filter="true" filterMatchMode="startsWith" panelStyle="width:220px">
                                     <f:selectItems var="custe3" value="#{structureBean.listCategorieStructure}"   itemLabel="#{custe3.intituleCategorieStructure}" itemValue="#{custe3.id}" itemLabelEscaped="true" />
                                </p:selectOneMenu>
                                <p:outputLabel value="Intitule :" for="intitule" />
                                <p:inputText id="intitule" value="#{structureBean.structureAttache.intituleStructure}" title="intitulé" />
                                <p:outputLabel value="Code/Abréviation :" for="abrev" />
                                <p:inputText id="abrev" value="#{structureBean.structureAttache.codeStructure}" title="abrev"/>
                                <h:inputHidden id="number" value="#{structureBean.structureAttache.id}" />
                                <p:commandButton value="Modifier" action="#{structureBean.updateStructure()}"  oncomplete="PF('dl').hide()" update=":tableForm:table" id="bout1" ajax="false" />
                    </p:panelGrid>
                </h:form>
            </p:dialog> 
        </f:view>


        <f:view>
            <h:form id='tableForm'>

                <p:dataTable value="#{structureBean.findAllStructure()}" var="item" paginator="true" rows="10" paginatorTemplate=" {CurrentPageReport} {FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown} " id="table" rowsPerPageTemplate="5,10,15" selectionMode="single" selection="#{structureBean.structureAttache}" rowKey="#{item.id}">
                             <f:facet name="header">
                                La liste des Structures d'attache
                             </f:facet>

                            <p:column>
                                <f:facet name="header">
                                    <h:outputText value="Structure"/>
                                </f:facet>
                                <h:outputText value="#{item.intituleStructure}"/>
                            </p:column>
                           <p:column>
                                <f:facet name="header">
                                    <h:outputText value="Code/Abréviation Structure"/>
                                </f:facet>
                                <h:outputText value="#{item.codeStructure}"/>
                            </p:column>

                            <p:column>
                                <f:facet name="header">
                                    <h:outputText value="Arrondissement"/>
                                </f:facet>
                                <h:outputText value="#{item.arrondissement.intituleArrondissement}"/>
                            </p:column>

                            <p:column>
                                <f:facet name="header">
                                    <h:outputText value="Département"/>
                                </f:facet>
                                <h:outputText value="#{item.arrondissement.departement.intituleDepartement}"/>
                            </p:column>


                </p:dataTable>
                <p:toolbar>
                    <f:facet name="left">
                        <p:commandButton type="push" onclick="PF('dlg').show();" value="Nouvelle Structure" icon="ui-icon-disk">
                            <p:ajax update=":formAjouter:panelAjouter" resetValues="true" />
                        </p:commandButton>
                        <p:commandButton  onclick="PF('dl').show()" value="Modifier Structure" update=":formModifier:panelGModifier" icon="ui-icon-arrowrefresh-1-w"/>

                        <span class="ui-separator">
                            <span class="ui-icon ui-icon-grip-dotted-vertical" />
                        </span>
                        <p:commandButton type="push" title="Save" image="ui-icon-disk" />
                        <p:commandButton type="push" title="Update" icon="ui-icon-arrowrefresh-1-w"/>
                        <p:commandButton type="push" title="Print" image="ui-icon-print"/>
                    </f:facet>
                </p:toolbar>
            </h:form>
        </f:view>
     </h:body>
</html>

Answer 1

您可以根据需要使用方法来初始化属性，然后通过 AJAX 或 actionListener，在尝试使用属性之前调用将完成工作的方法。