Primefaces。綁定數據模型不起作用。 ListDataModel.getWrappedData（）返回null

Question

我在Tomcat 7.0.23上嘗試這個example。 由於getWrappedData（）返回null，因此對話框「dialog」和「multiDialog」在填充行時未填充。這是CarDataModel的getRowData方法中的一行List<Car> cars = (List<Car>) getWrappedData();。

如果我使用rowKey屬性而不是綁定，它的工作原理。

<p:dataTable id="cars" var="car" value="#{tableBean.cars}" paginator="true" rows="10" 
       selection="#{tableBean.selectedCar}" 
       rowKey="#{car.model}"> 

什麼問題？

這裏是我的pom.xml

<dependency> 
    <groupId>org.primefaces</groupId> 
    <artifactId>primefaces</artifactId> 
    <version>3.4</version> 
</dependency> 
<dependency> 
    <groupId>com.sun.faces</groupId> 
    <artifactId>jsf-api</artifactId> 
    <version>2.1.13</version> 
    <scope>compile</scope> 
</dependency> 
<dependency> 
    <groupId>com.sun.faces</groupId> 
    <artifactId>jsf-impl</artifactId> 
    <version>2.1.13</version> 
    <scope>compile</scope> 
</dependency> 

我CarDataModel

package data; 
import java.io.Serializable; 
import java.util.List; 
import javax.faces.model.ListDataModel; 
import org.primefaces.model.SelectableDataModel; 

public class CarDataModel extends ListDataModel<Car> implements SelectableDataModel<Car>, Serializable{  
    private static final long serialVersionUID = -6094333899604122284L; 

    public CarDataModel() { 
    } 

    public CarDataModel(List<Car> data) { 
     super(data); 
    } 

    @Override 
    @SuppressWarnings("unchecked") 
    public Car getRowData(String rowKey) { 
     //In a real app, a more efficient way like a query by rowKey should be implemented to deal with huge data 
     List<Car> cars = (List<Car>) getWrappedData(); 
     for (Car car : cars) { 
      if (car.getModel().equals(rowKey)) 
       return car; 
     } 
     return null; 
    } 

    @Override 
    public Object getRowKey(Car car) { 
     return car.getModel(); 
    } 
} 

我TableBean

package data; 
import java.io.Serializable; 
import java.util.ArrayList; 
import java.util.List; 
import java.util.UUID; 
import javax.faces.bean.ManagedBean; 
import javax.faces.bean.ViewScoped; 

@ManagedBean 
@ViewScoped 
public class TableBean implements Serializable { 
    private static final long serialVersionUID = 2213388781051004157L; 

    private final static String[] colors; 

    private final static String[] manufacturers; 

    static { 
     colors = new String[10]; 
     colors[0] = "Black"; 
     colors[1] = "White"; 
     colors[2] = "Green"; 
     colors[3] = "Red"; 
     colors[4] = "Blue"; 
     colors[5] = "Orange"; 
     colors[6] = "Silver"; 
     colors[7] = "Yellow"; 
     colors[8] = "Brown"; 
     colors[9] = "Maroon"; 

     manufacturers = new String[10]; 
     manufacturers[0] = "Mercedes"; 
     manufacturers[1] = "BMW"; 
     manufacturers[2] = "Volvo"; 
     manufacturers[3] = "Audi"; 
     manufacturers[4] = "Renault"; 
     manufacturers[5] = "Opel"; 
     manufacturers[6] = "Volkswagen"; 
     manufacturers[7] = "Chrysler"; 
     manufacturers[8] = "Ferrari"; 
     manufacturers[9] = "Ford"; 
    } 

    private List<Car> cars; 

    private Car selectedCar; 

    private Car[] selectedCars; 

    private CarDataModel mediumCarsModel; 

    public TableBean() { 
     cars = new ArrayList<Car>(); 

     populateRandomCars(cars, 50); 

     mediumCarsModel = new CarDataModel(cars); 
    } 

    public Car[] getSelectedCars() { 
     return selectedCars; 
    } 
    public void setSelectedCars(Car[] selectedCars) { 
     this.selectedCars = selectedCars; 
    } 

    public Car getSelectedCar() { 
     return selectedCar; 
    } 

    public void setSelectedCar(Car selectedCar) { 
     this.selectedCar = selectedCar; 
    } 

    private void populateRandomCars(List<Car> list, int size) { 
     for(int i = 0 ; i < size ; i++) 
      list.add(new Car(getRandomModel(), getRandomYear(), getRandomManufacturer(), getRandomColor())); 
    } 

    private int getRandomYear() { 
     return (int) (Math.random() * 50 + 1960); 
    } 

    private String getRandomColor() { 
     return colors[(int) (Math.random() * 10)]; 
    } 

    private String getRandomManufacturer() { 
     return manufacturers[(int) (Math.random() * 10)]; 
    } 

    private String getRandomModel() { 
     return UUID.randomUUID().toString().substring(0, 8); 
    } 

    public CarDataModel getMediumCarsModel() { 
     return mediumCarsModel; 
    } 

    public List<Car> getCars() { 
     return cars; 
    } 
} 

我datatableRowSelectionRadioCheckbox.xhtml

<?xml version="1.0" encoding="UTF-8"?> 
<ui:composition xmlns="http://www.w3.org/1999/xhtml" 
    xmlns:ui="http://java.sun.com/jsf/facelets" 
    xmlns:f="http://java.sun.com/jsf/core" 
    xmlns:h="http://java.sun.com/jsf/html" 
    xmlns:p="http://primefaces.org/ui" 
    template="/WEB-INF/templates/template.xhtml"> 
    <ui:define name="title">DataTable - RadioCheckbox</ui:define> 
    <ui:define name="content"> 
     <h:form id="form"> 

      <p:dataTable id="cars" var="car" value="#{TableBean.mediumCarsModel}" paginator="true" rows="10" 
       selection="#{TableBean.selectedCar}"> 

       <f:facet name="header"> 
        RadioButton Based Selection 
       </f:facet> 

       <p:column selectionMode="single" style="width:18px" /> 

       <p:column headerText="Model"> 
        #{car.model} 
       </p:column> 

       <p:column headerText="Year"> 
        #{car.year} 
       </p:column> 

       <p:column headerText="Manufacturer" > 
        #{car.manufacturer} 
       </p:column> 

       <p:column headerText="Color"> 
        #{car.color} 
       </p:column> 

       <f:facet name="footer"> 
        <p:commandButton id="viewCommand" value="View" icon="ui-icon-search" 
            update=":form:displaySingle" oncomplete="singleCarDialog.show()"/> 
       </f:facet> 
      </p:dataTable> 

      <p:dataTable id="multiCars" var="car" value="#{TableBean.mediumCarsModel}" paginator="true" rows="10" 
       selection="#{TableBean.selectedCars}"> 

       <f:facet name="header"> 
        Checkbox Based Selection 
       </f:facet> 

       <p:column selectionMode="multiple" style="width:18px" /> 

       <p:column headerText="Model"> 
        #{car.model} 
       </p:column> 

       <p:column headerText="Year"> 
        #{car.year} 
       </p:column> 

       <p:column headerText="Manufacturer" > 
        #{car.manufacturer} 
       </p:column> 

       <p:column headerText="Color"> 
        #{car.color} 
       </p:column> 

       <f:facet name="footer"> 
        <p:commandButton id="multiViewButton" value="View" icon="ui-icon-search" 
            update=":form:displayMulti" oncomplete="multiCarDialog.show()"/> 
       </f:facet> 
      </p:dataTable> 

      <p:dialog id="dialog" header="Car Detail" widgetVar="singleCarDialog" resizable="false" 
         showEffect="fade" hideEffect="explode"> 

       <h:panelGrid id="displaySingle" columns="2" cellpadding="4"> 

        <f:facet name="header"> 
         <ui:param name="resourceName" value="images:cars/#{TableBean.selectedCar.manufacturer}.jpg"/> 
         <p:graphicImage value="#{resource[resourceName]}"/> 
        </f:facet> 

        <h:outputText value="Model:" /> 
        <h:outputText value="#{TableBean.selectedCar.model}" /> 

        <h:outputText value="Year:" /> 
        <h:outputText value="#{TableBean.selectedCar.year}" /> 

        <h:outputText value="Manufacturer:" /> 
        <h:outputText value="#{TableBean.selectedCar.manufacturer}" /> 

        <h:outputText value="Color:" /> 
        <h:outputText value="#{TableBean.selectedCar.color}" /> 
       </h:panelGrid> 
      </p:dialog> 

      <p:dialog id="multiDialog" header="Car Detail" widgetVar="multiCarDialog" 
         height="300" showEffect="fade" hideEffect="explode"> 

       <p:dataList id="displayMulti" 
         value="#{TableBean.selectedCars}" var="selectedCar"> 
        Model: #{selectedCar.model}, Year: #{selectedCar.year} 
       </p:dataList> 

      </p:dialog> 

     </h:form> 
    </ui:define> 
</ui:composition> 

片段

我的template.xhtml

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd" 
[ 
    <!ENTITY nbsp "&#160;"> 
]> 
<html xmlns="http://www.w3.org/1999/xhtml" 
    xmlns:h="http://java.sun.com/jsf/html" 
    xmlns:ui="http://java.sun.com/jsf/facelets"> 
<ui:insert name="metadata"/> 
<h:head> 
    <title>My Primefaces</title> 
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
    <h:outputStylesheet name="css/default.css" /> 
    <h:outputStylesheet name="css/primefaces.css" /> 
    <h:outputStylesheet name="css/syntaxhighlighter.css" /> 
    <h:outputStylesheet name="css/theme.css" /> 
</h:head> 
<h:body> 
    <div id="header" class="ui-widget ui-widget-header"> 
      <div id="logo"> 
       <img src="#{resource['images:logo.png']}" alt="Logo" /> 
      </div> 
    </div> 
    <div id="page" class="ui-widget"> 
     <ui:include src="/sidebar/mainmenu.xhtml"/> 

     <div id="content"> 
      <div class="post"> 
       <h1 class="title ui-widget-header ui-corner-all"><ui:insert name="title">Title</ui:insert></h1> 
       <div class="entry" style="line-height:200%"> 
        <ui:insert name="content">Main Content</ui:insert> 

       </div> 
      </div> 
     </div> 
     <div style="clear: both;">&nbsp;</div> 
    </div> 

    <div id="footer" class="ui-widget ui-widget-header ui-corner-all"> 
     <p class="copyright">My test of PrimeFaces-3.4</p> 
    </div> 
</h:body> 
</html> 

Answer 1

它是由的context-param STATE_SAVING_METHOD =客戶端造成的。它必須是「服務器」。