После некоторых экспериментов, это кажется проблемой при использовании bean-компонента CDI и не имеет ничего общего с PrimeFaces, как я и предполагал изначально.

Если я изменю TableBeanLazy на управляемый компонент с использованием @ManagedBean, то конструктор и метод @PostConstruct будут вызываться только один раз, как я и ожидал.

Кто-нибудь может пролить свет на это?

================================================== знак равно

Я довольно новичок в JSF и PrimeFaces, поэтому любые рекомендации будут с благодарностью. Я искал другие публикации и прочитал несколько похожих, но не могу найти решение.

Я пытаюсь получить пример Lazy Loading Data Table на сайте PrimeFaces Showcase, работающий в моем проекте, но у меня возникают проблемы из-за того, что класс bean-компонентов ведет себя не так, как я ожидал.

Я сделал несколько изменений в примере кода с сайта PrimeFaces: - переименовал класс TableBean в TableBeanLazy; добавлены аннотации к классу; выделенные статические массивы String; переместил инициализацию из конструктора в метод @PostConstruct initialise (); выделилмашины переменная-член.

Я также добавил сообщения трассировки в конструктор и метод @PostConstruct, которые показывают, что оба они вызываются несколько раз при первом отображении таблицы, несколько раз при каждом щелчке значка поиска и несколько раз при каждой записи символа в поле фильтра.

Это приводит к тому, что случайный список объектов Car воссоздается каждый раз, когда предпринимается какое-либо действие, поэтому сортировка и фильтрация никогда не приведут к ожидаемым результатам - что они делают при запуске примера непосредственно на сайте PrimeFaces Showcase.

Хотя я первоначально использовал @ViewScoped, я также попробовал @RequestScoped и, наконец, @SessionScoped, но все ведут себя одинаково.

Является ли несколько вызовов конструктора и @PostConstruct ожидаемым поведением для компонента?

Если да, то как может работать пример кода, представленный на сайте PrimeFaces Showcase?

Как мне решить это?

Окружающая обстановка

PrimeFaces 3.5
JSF 2.1
JDK 1.7
GlassFish Server Open Source Edition 3.1.2.2 (build 5)
Mojarra 2.1.6 (SNAPSHOT 20111206)
Netbeans IDE 7.3
Windows 7 Pro x64

MyTable.xhtml

<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE composition PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<ui:composition xmlns="http://www.w3.org/1999/xhtml"
  xmlns:ui="http://java.sun.com/jsf/facelets"
  template="./resources/templates/platform_tpl.xhtml"
  xmlns:p="http://primefaces.org/ui"
  xmlns:h="http://java.sun.com/jsf/html"
  xmlns:f="http://java.sun.com/jsf/core">

  <ui:define name="body">
    <h2 style="margin-top: 0px; padding-top: 0px;">Cars List</h2>

    <h:form id="form">
      <p:dataTable var="car" value="#{tableBeanLazy.lazyModel}" paginator="true" rows="10"
        paginatorTemplate="{RowsPerPageDropdown} {FirstPageLink} {PreviousPageLink} {CurrentPageReport} {NextPageLink} {LastPageLink}"
        rowsPerPageTemplate="5,10,15" selectionMode="single" selection="#{tableBeanLazy.selectedCar}" id="carTable" lazy="true">

      <p:column headerText="Model" sortBy="#{car.model}" filterBy="#{car.model}">
        <h:outputText value="#{car.model}" />
      </p:column>

      <p:column headerText="Year" sortBy="#{car.year}" filterBy="#{car.year}">
        <h:outputText value="#{car.year}" />
      </p:column>

      <p:column headerText="Manufacturer" sortBy="#{car.manufacturer}" filterBy="#{car.manufacturer}">
        <h:outputText value="#{car.manufacturer}" />
      </p:column>

      <p:column headerText="Color" sortBy="#{car.color}" filterBy="#{car.color}">
        <h:outputText value="#{car.color}" />
      </p:column>
      </p:dataTable>
    </h:form> 
  </ui:define>
</ui:composition>

TableBeanLazy.java

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package BackEnd;

import java.util.ArrayList;
import java.util.List;  
import javax.annotation.PostConstruct;
import javax.faces.bean.SessionScoped;
import javax.inject.Named;

import org.primefaces.model.LazyDataModel;  

@Named(value = "tableBeanLazy")
@SessionScoped
public class TableBeanLazy
{
  static String[] colors = new String[10];
  static String[] manufacturers = new String[10];
  static String[] models = new String[5];

  private LazyDataModel<Car> lazyModel;  

  private Car selectedCar;  

  private List<Car> cars;  

  static
  {
    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[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";

    models[0] = "Sports";
    models[1] = "Saloon";
    models[2] = "SUV";
    models[3] = "Hybrid";
    models[4] = "Estate";
  }  

  public TableBeanLazy()
  {
    System.out.println("-->  In constructor for TableBeanLazy");
  }

  @PostConstruct
  public void initialise()
  {
    System.out.println("-->  In initialise for TableBeanLazy");

    cars = new ArrayList<Car>();

    populateRandomCars(cars, 5);

    lazyModel = new LazyCarDataModel(cars);  
  }

  public Car getSelectedCar()
  {
    return selectedCar;
  }  

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

  public LazyDataModel<Car> getLazyModel()
  {
    return lazyModel;
  }

  private void populateRandomCars(List<Car> list, int size)
  {
    System.out.println("-->  In populateRandomCars for TableBeanLazy");

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

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

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

  private String getRandomModel()
  {
    return models[(int)(Math.random() * 5)];
  }

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

Вывод на начальный показ таблицы

INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy

Вывод при нажатии на значок поиска

INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: java.lang.ArithmeticException: / by zero
java.lang.ArithmeticException: / by zero
  at org.primefaces.model.LazyDataModel.setRowIndex(LazyDataModel.java:62)
  at org.primefaces.component.api.UIData.setRowModel(UIData.java:409)
  at org.primefaces.component.api.UIData.setRowIndex(UIData.java:401)
  at org.primefaces.component.api.UIData.processChildren(UIData.java:289)
  at org.primefaces.component.api.UIData.processPhase(UIData.java:261)
  at org.primefaces.component.api.UIData.processDecodes(UIData.java:227)
  at com.sun.faces.context.PartialViewContextImpl$PhaseAwareVisitCallback.visit(PartialViewContextImpl.java:506)
  at com.sun.faces.component.visit.PartialVisitContext.invokeVisitCallback(PartialVisitContext.java:183)
  at org.primefaces.component.api.UIData.visitTree(UIData.java:639)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIForm.visitTree(UIForm.java:344)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at com.sun.faces.context.PartialViewContextImpl.processComponents(PartialViewContextImpl.java:376)
  at com.sun.faces.context.PartialViewContextImpl.processPartial(PartialViewContextImpl.java:252)
  at javax.faces.context.PartialViewContextWrapper.processPartial(PartialViewContextWrapper.java:183)
  at javax.faces.component.UIViewRoot.processDecodes(UIViewRoot.java:931)
  at com.sun.faces.lifecycle.ApplyRequestValuesPhase.execute(ApplyRequestValuesPhase.java:78)
  at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
  at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
  at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
  at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1550)
  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
  at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
  at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161)
  at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331)
  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
  at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317)
  at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
  at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860)
  at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:757)
  at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1056)
  at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:229)
  at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
  at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
  at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
  at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
  at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
  at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
  at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
  at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
  at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
  at java.lang.Thread.run(Thread.java:722)

INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: java.lang.ArithmeticException: / by zero
java.lang.ArithmeticException: / by zero
  at org.primefaces.model.LazyDataModel.setRowIndex(LazyDataModel.java:62)
  at org.primefaces.component.api.UIData.setRowModel(UIData.java:409)
  at org.primefaces.component.api.UIData.setRowIndex(UIData.java:401)
  at org.primefaces.component.api.UIData.processChildren(UIData.java:289)
  at org.primefaces.component.api.UIData.processPhase(UIData.java:261)
  at org.primefaces.component.api.UIData.processValidators(UIData.java:241)
  at com.sun.faces.context.PartialViewContextImpl$PhaseAwareVisitCallback.visit(PartialViewContextImpl.java:508)
  at com.sun.faces.component.visit.PartialVisitContext.invokeVisitCallback(PartialVisitContext.java:183)
  at org.primefaces.component.api.UIData.visitTree(UIData.java:639)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIForm.visitTree(UIForm.java:344)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at com.sun.faces.context.PartialViewContextImpl.processComponents(PartialViewContextImpl.java:376)
  at com.sun.faces.context.PartialViewContextImpl.processPartial(PartialViewContextImpl.java:252)
  at javax.faces.context.PartialViewContextWrapper.processPartial(PartialViewContextWrapper.java:183)
  at javax.faces.component.UIViewRoot.processValidators(UIViewRoot.java:1170)
  at com.sun.faces.lifecycle.ProcessValidationsPhase.execute(ProcessValidationsPhase.java:76)
  at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
  at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
  at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
  at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1550)
  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
  at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
  at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161)
  at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331)
  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
  at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317)
  at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
  at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860)
  at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:757)
  at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1056)
  at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:229)
  at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
  at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
  at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
  at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
  at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
  at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
  at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
  at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
  at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
  at java.lang.Thread.run(Thread.java:722)

INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: java.lang.ArithmeticException: / by zero
java.lang.ArithmeticException: / by zero
  at org.primefaces.model.LazyDataModel.setRowIndex(LazyDataModel.java:62)
  at org.primefaces.component.api.UIData.setRowModel(UIData.java:409)
  at org.primefaces.component.api.UIData.setRowIndex(UIData.java:401)
  at org.primefaces.component.api.UIData.processChildren(UIData.java:289)
  at org.primefaces.component.api.UIData.processPhase(UIData.java:261)
  at org.primefaces.component.api.UIData.processUpdates(UIData.java:253)
  at org.primefaces.component.datatable.DataTable.processUpdates(DataTable.java:550)
  at com.sun.faces.context.PartialViewContextImpl$PhaseAwareVisitCallback.visit(PartialViewContextImpl.java:510)
  at com.sun.faces.component.visit.PartialVisitContext.invokeVisitCallback(PartialVisitContext.java:183)
  at org.primefaces.component.api.UIData.visitTree(UIData.java:639)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIForm.visitTree(UIForm.java:344)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at javax.faces.component.UIComponent.visitTree(UIComponent.java:1601)
  at com.sun.faces.context.PartialViewContextImpl.processComponents(PartialViewContextImpl.java:376)
  at com.sun.faces.context.PartialViewContextImpl.processPartial(PartialViewContextImpl.java:252)
  at javax.faces.context.PartialViewContextWrapper.processPartial(PartialViewContextWrapper.java:183)
  at javax.faces.component.UIViewRoot.processUpdates(UIViewRoot.java:1229)
  at com.sun.faces.lifecycle.UpdateModelValuesPhase.execute(UpdateModelValuesPhase.java:78)
  at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
  at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
  at javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
  at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1550)
  at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:281)
  at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
  at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:655)
  at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:595)
  at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:161)
  at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:331)
  at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:231)
  at com.sun.enterprise.v3.services.impl.ContainerMapper$AdapterCallable.call(ContainerMapper.java:317)
  at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:195)
  at com.sun.grizzly.http.ProcessorTask.invokeAdapter(ProcessorTask.java:860)
  at com.sun.grizzly.http.ProcessorTask.doProcess(ProcessorTask.java:757)
  at com.sun.grizzly.http.ProcessorTask.process(ProcessorTask.java:1056)
  at com.sun.grizzly.http.DefaultProtocolFilter.execute(DefaultProtocolFilter.java:229)
  at com.sun.grizzly.DefaultProtocolChain.executeProtocolFilter(DefaultProtocolChain.java:137)
  at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:104)
  at com.sun.grizzly.DefaultProtocolChain.execute(DefaultProtocolChain.java:90)
  at com.sun.grizzly.http.HttpProtocolChain.execute(HttpProtocolChain.java:79)
  at com.sun.grizzly.ProtocolChainContextTask.doCall(ProtocolChainContextTask.java:54)
  at com.sun.grizzly.SelectionKeyContextTask.call(SelectionKeyContextTask.java:59)
  at com.sun.grizzly.ContextTask.run(ContextTask.java:71)
  at com.sun.grizzly.util.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:532)
  at com.sun.grizzly.util.AbstractThreadPool$Worker.run(AbstractThreadPool.java:513)
  at java.lang.Thread.run(Thread.java:722)

INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy
INFO: -->  In constructor for TableBeanLazy
INFO: -->  In initialise for TableBeanLazy
INFO: -->  In populateRandomCars for TableBeanLazy