【发布时间】：2014-01-21 10:25:05
【问题描述】：
我有一个我无法解决的问题。我有我的 xhtml 页面：
问题是我有一个表格，我可以在其中插入姓名并选择旅行地点。它呈现一个外部面板“Volo”，其中 selectionMenu 会根据所选位置使用从 DB 获取的一些值进行更新。接下来，我想从 Volo 选择中获取一个值，并使用 ID="HE" 更新另一个面板（即名为 HotelEsc 的面板）。 我在“Volo”中的 selectionMenu 遇到了麻烦，因为我无法将值放入其中。总是给出 NullPointException 错误。问题可能是我试图了解更新和渲染是如何工作的，而我对这些操作有误解。希望得到您的帮助，谢谢。
xhtml代码：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<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:ui="http://java.sun.com/jsf/facelets"
xmlns:p="http://primefaces.org/ui">
<h:head>
<title>Add a Default Package</title>
</h:head>
<h:body>
<h:form id="form">
<p:panel header="DefaultPackage Form">
<h:panelGrid columns="3" id="regGrid">
<h:outputLabel for="Name">Name:</h:outputLabel>
<p:inputText id="Name"
value="#{addDefaultPackageBean.defpackDTO.name}" />
<p:message for="Name" />
<h:outputLabel for="location">Locations Available:</h:outputLabel>
<h:selectOneMenu for="location"
value="#{addDefaultPackageBean.defpackDTO.location}">
<f:ajax listener="#{addDefaultPackageBean.Search()}" render="Volo" />
<f:selectItems id="location"
value="#{addDefaultPackageBean.availableLocations}" />
</h:selectOneMenu>
</h:panelGrid>
</p:panel>
<p:panel header="Voli Disponibili per la location selezionata"
id="Volo">
<h:outputLabel for="Fly">Volo:</h:outputLabel>
<h:selectOneMenu for="Fly" value="#{addDefaultPackageBean.fly}">
<f:selectItems id="Fly" value="#{addDefaultPackageBean.elelisfly}"
var="ElementDTO" itemValue="#{ElementDTO.name}"
itemLabel="#{ElementDTO.name}" />
</h:selectOneMenu>
<p:commandButton action="#{addDefaultPackageBean.sel()}" value="HE" render=":form,:form:regularGrid,:form:Volo" update=":form:Volo" process="form:regGrid,@this"></p:commandButton>
</p:panel>
<p:panel header="HotelEsc" id="HotelEscursioni">
<h:panelGrid columns="3" id="regularGrid">
<h:outputLabel for="Hotel">Hotel:</h:outputLabel>
<h:selectOneMenu for="Hotel" value="#{addDefaultPackageBean.hotel}">
<f:selectItems id="Hotel"
value="#{addDefaultPackageBean.elelishotel}" var="ElementDTO"
itemValue="#{ElementDTO.name}" itemLabel="#{ElementDTO.name}" />
</h:selectOneMenu>
<p:message for="Hotel" />
<h:outputLabel for="Escursion">Escursioni:</h:outputLabel>
<f:facet name="header">Clicca su view per vedere i dettagli</f:facet>
<p:dataTable id="Escursion" var="esc"
value="#{addDefaultPackageBean.elelisescursion}"
rowKey="#{esc.name}"
selection="#{addDefaultPackageBean.selectedEscursions}"
selectionMode="multiple">
<p:column headerText="Nome"> #{esc.name} </p:column>
<p:column headerText="Costo"> #{esc.cost} </p:column>
<p:column headerText="Data Iniziale"> #{esc.startingDate} </p:column>
<p:column headerText="Data Fine"> #{esc.endingDate} </p:column>
<f:facet name="footer">
</f:facet>
</p:dataTable>
</h:panelGrid>
</p:panel>
</h:form>
</h:body>
</html>
相关bean的代码：
package beans;
import java.awt.Event;
import java.io.Serializable;
import java.util.ArrayList;
import javax.annotation.PostConstruct;
import javax.ejb.EJB;
import javax.enterprise.context.SessionScoped;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import javax.faces.view.ViewScoped;
import elementManagement.ElementMgr;
import elementManagementDTO.ElementDTO;
import DefaultPackageManagement.DefaultPackageMgr;
import DefaultPackageManagementDTO.DefaultPackageDTO;
@ManagedBean(name="addDefaultPackageBean") //come viene richiamato
@ViewScoped
public class AddDefaultPackageBean{
/**
*
*/
@EJB
private DefaultPackageMgr defpackMgr;
private DefaultPackageDTO defpackDTO;
private ArrayList<ElementDTO> elelisfly;
private ArrayList<ElementDTO> elelishotel;
private ArrayList<ElementDTO> elelisescursion;
private ArrayList<ElementDTO> elelis;
private ElementDTO[] selectedEscursions;
private String fly;
private String hotel;
private boolean flag=true;
private boolean flagdopo=true;
private ArrayList<String> availableLocations;
private ElementDTO flyElem;
@EJB
private ElementMgr elemMgr;
public ElementDTO[] getSelectedEscursions() {
return selectedEscursions;
}
public void setSelectedEscursions(ElementDTO[] selectedEscursions) {
this.selectedEscursions = selectedEscursions;
}
public AddDefaultPackageBean() {
defpackDTO = new DefaultPackageDTO();
}
@PostConstruct
public void init()
{
this.elelisfly=new ArrayList<ElementDTO>();
this.elelishotel=new ArrayList<ElementDTO>();
this.elelisescursion=new ArrayList<ElementDTO>();
this.setElelis(elemMgr.getAllElements());
this.availableLocations=new ArrayList<String>();
this.flyElem=new ElementDTO();
for(ElementDTO e:elelis)
{
if (this.availableLocations.contains(e.getLocation())==false)
{
this.availableLocations.add(e.getLocation());
}
}
}
public String add() {
this.AssignElemFlyFromSelection();
this.AssignElemHotelFromSelection();
this.AssignElemEscursionFromSelection();
defpackMgr.save(defpackDTO);
return "/employee/index?faces-redirect=true";
}
public void sel()
{
System.out.print("ehila" );
this.setElelis(this.elemMgr.getAllElementsByLocation(this.defpackDTO.getLocation()));
for(ElementDTO e:elelis)
{
System.out.print("elemento della location Haiti "+e.getName());
}
this.AssignElemFlyFromSelection();
System.out.print(this.fly+"Il volo selezionato per la location è "+this.getFlyElem().getName() );
this.elelisescursion.clear();
this.elelishotel.clear();
for(ElementDTO e:elelis)
{
if(e.getType().equals("Hotel"))
{
System.out.print("ho un hotel tra gli elementi "+e.getName() );
if(e.getStartingDate().after(this.flyElem.getStartingDate())&&((e.getEndingDate().before(this.flyElem.getEndingDate()))))
{
System.out.print("ho un hotel tra gli elementi con le date giuste"+e.getName());
this.getElelishotel().add(e);
}
}
else
{
if(e.getType().equals("Escursion"))
{
if(e.getStartingDate().after(this.flyElem.getStartingDate())&&(e.getEndingDate().before(this.flyElem.getEndingDate())))
{
this.getElelishotel().add(e);
}
}
}
}
this.setFlag(true);
this.setFlagdopo(true);
}
public DefaultPackageDTO getDefpackDTO() {
return defpackDTO;
}
public void setDefpackDTO(DefaultPackageDTO defpackDTO) {
this.defpackDTO = defpackDTO;
}
public ArrayList<ElementDTO> getElelisfly() {
return elelisfly;
}
public void setElelisfly(ArrayList<ElementDTO> elelisfly) {
this.elelisfly = elelisfly;
}
public ArrayList<ElementDTO> getElelishotel() {
return elelishotel;
}
public void setElelishotel(ArrayList<ElementDTO> elelishotel) {
this.elelishotel = elelishotel;
}
public ArrayList<ElementDTO> getElelisescursion() {
return elelisescursion;
}
public void setElelisescursion(ArrayList<ElementDTO> elelisescursion) {
this.elelisescursion = elelisescursion;
}
public String getFly() {
return fly;
}
public void setFly(String fly) {
this.fly = fly;
}
public String getHotel() {
return hotel;
}
public void setHotel(String hotel) {
this.hotel = hotel;
}
private void AssignElemFlyFromSelection()
{
for (ElementDTO elem:this.elelisfly)
{
if(elem.getName().equals(this.fly))
{
this.flyElem=elem;
}
}
}
private void AssignElemHotelFromSelection()
{
for (ElementDTO elem:this.elelishotel)
{
if(elem.getName().equals(this.hotel))
{
this.defpackDTO.getElem().add(elem);
}
}
}
private void AssignElemEscursionFromSelection()
{
for(int i=0;i<selectedEscursions.length;i++)
{
this.defpackDTO.getElem().add(selectedEscursions[i]);
}
}
public void Search(){
String s=defpackDTO.getLocation();
System.out.print("luogo scelto "+s);
this.setElelis(this.elemMgr.getAllElementsByLocation(s));
for(ElementDTO e:elelis)
{
System.out.print("aggiungo volo "+e.getName());
if(e.getType().equals("Flight"))
{
this.getElelisfly().add(e);
System.out.print("aggiungo volo "+e.getName());
}
}
this.setFlag(true);
}
public ArrayList<ElementDTO> getElelis() {
return elelis;
}
public void setElelis(ArrayList<ElementDTO> elelis) {
this.elelis = elelis;
}
public ArrayList<String> getAvailableLocations() {
return availableLocations;
}
public void setAvailableLocations(ArrayList<String> availableLocations) {
this.availableLocations = availableLocations;
}
public Boolean getFlag() {
return flag;
}
public void setFlag(Boolean flag) {
this.flag = flag;
}
public boolean isFlagdopo() {
return flagdopo;
}
public void setFlagdopo(boolean flagdopo) {
this.flagdopo = flagdopo;
}
public ElementDTO getFlyElem() {
return flyElem;
}
public void setFlyElem(ElementDTO flyElem) {
this.flyElem = flyElem;
}
}
【问题讨论】：
标签： jsf jsf-2 primefaces