Question

我已经实施了以下选项列表：

<p:pickList id="pickList" value="#{reportConfiguratorBean.dualListVars}" var="cRVariable" itemValue="#{cRVariable}" itemLabel="#{cRVariable.varName}" converter="#{cRImageTypeConverter}" immediate="true" rendered="true" >
    <f:facet name="sourceCaption">Available Variables</f:facet>
    <f:facet name="targetCaption">Associated Variables</f:facet>                
</p:pickList>                       
<f:facet name="footer"> 
    <p:commandButton id='varassociate' action="#{reportConfiguratorBean.setAssocImTypVariables()}" value='Associate' process="@this,pickList" />
</f:facet>

正确填充了选择列表（使用数据库中的getAssocImTypVariables（））。但是我的 ISSUE 是我无法捕获用户更改的选项列表值会改变源列表和目标列表。我试图使用commandButton方法“setAssocImTypVariables”捕获更改，如下所示：

public void setAssocImTypVariables() {      
    System.out.println(">>>>>>>>>>>>>>> entered");          
    List<CRVariable> sourceVariables = this.dualListVars.getSource();
    List<CRVariable> targetVariables = this.dualListVars.getTarget();       

    System.out.println(dualListVars.getSource());
    System.out.println(dualListVars.getTarget());

    for (CRVariable sourceVariable:sourceVariables) {
        System.out.println(">>>>>>>>>>>>> I am a source variable: " + sourceVariable.getVarName());
    }       
    for (CRVariable targetVariable:targetVariables) {
        System.out.println(">>>>>>>>>>>>> I am a target variable: " + targetVariable.getVarName());
    }       
    }

因此，如果我有一个带有INITIAL source =（Obj1，Obj2，Obj3，Obj5，Obj7）和target =（Obj4，Obj6）的选项列表，我在我的控制台中将“Obj1”从源移动到目标BUT ：

---------输入 [] []

所以我的dualListVars（源和目标）没有填充！我有两个关于源和目标的空列表......

所以我的方法无法察觉选项列表的变化......有什么想法吗？我是java + primefaces的新手，所以它可能是非常基础的东西：（

我还附加方法getAssocImTypesOnLoad（）：

public void getAssocImTypesOnLoad() {               
    Long imTypeId = Long.parseLong(virtualId);      
    List<CRVariable> source;
    List<CRVariable> target;        
    Session session = HibernateUtil.getSessionFactory().openSession();
    Transaction tx = null;      
    try 
    {
        tx = session.beginTransaction();            
        String hq3 = "select distinct v from CRVariable v join v.crimagetypes t where t.id in (:itid)";
        Query query3 = session.createQuery(hq3);
        query3.setParameter("itid",imTypeId);
        target = query3.list();
        String hq4 = "select v FROM CRVariable v WHERE v.id not in (" +
                "select distinct v1.id " +
                "from CRVariable v1 " +
                "join v1.crimagetypes t2 " +
                "where t2.id in (:itid))";
        Query query4 = session.createQuery(hq4);
        query4.setParameter("itid",imTypeId);
        source = query4.list();
        dualListVars = new DualListModel<CRVariable>(source, target);
        tx.commit();
    } 
    catch (Exception e) 
    {
        if (tx != null) 
        {
            e.printStackTrace();
        }
    } 
    finally 
    {
       session.close();
    }
}

Answer 1

仔细查看primefaces展示：Primefaces picklist

直接致电dualListVars。 #{reportConfiguratorBean.dualListVars}已解析为reportConfiguratorBean.getDualListVars()，因为dualListVars是一个属性（例如，带有getter和setter的属性）。

<p:pickList id="pickList" value="#{reportConfiguratorBean.dualListVars}" var="cRVariable" itemValue="#{cRVariable}" itemLabel="#{cRVariable.varName}" converter="#{cRImageTypeConverter}" immediate="true" rendered="true" >
    <f:facet name="sourceCaption">Available Variables</f:facet>
    <f:facet name="targetCaption">Associated Variables</f:facet>                
</p:pickList>

action属性适用于业务逻辑。你可以在这里找到源和目标列表。 process属性告诉JSF要处理哪些组件。在您的情况下，您希望处理组件picklist和commandButton。您还可以使用process="@form"处理整个表单。

<p:commandButton id='varassociate' action="#{reportConfiguratorBean.readMyAssocImTypVariables}" value='Associate' ajax='false' process="@this,pickList" immediate="true" />

readMyAssocImTypVariables函数：

 public void readMyAssocImTypVariables() {      
    List<CRVariable> sourceVariables = this.dualListVars.getSource();
    List<CRVariable> targetVariables = this.dualListVars.getTarget();       
    for (CRVariable sourceVariable:sourceVariables) {
        System.out.println(">>>>>>>>>>>>> I am a source variable: " + sourceVariable.getVarName());
    }       
    for (CRVariable targetVariable:targetVariables) {
        System.out.println(">>>>>>>>>>>>> I am a target variable: " + targetVariable.getVarName());
     }       
  }

无关：不要将业务逻辑放入getter / setter中！它们被JSF多次调用。

Answer 2

为什么在immediate=true上使用commandButton属性？

根据balusC的文章，如果我没记错的话 check it out here commandButton上的immediate=true应跳过apply model to values phase。

也许这就是为什么你的模型没有更新的原因？

（只是通过查看代码来猜测 - 我没有复制过这个。）

Answer 3

正在运行的选项列表示例 picklist.xhtml

<!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:p="http://primefaces.org/ui"
xmlns:ui="http://java.sun.com/jsf/facelets">


<h:head></h:head>

<h:body>
<h:form>
    <h3>Basic PickList</h3>
    <p:pickList value="#{pickListBean.cities}" var="city"
        itemLabel="#{city}" itemValue="#{city}" />
<p:commandButton  value="Submit" action="#{pickListBean.displayList}" />    


</h:form>

</h:body>
</html>

PickListBean.java

import java.util.ArrayList;
import java.util.List;

import javax.faces.bean.ManagedBean;
import org.primefaces.model.DualListModel;

@ManagedBean
public class PickListBean {

   private DualListModel<String> cities;

   public PickListBean() {

  //Cities
  List<String> citiesSource = new ArrayList<String>();
  List<String> citiesTarget = new ArrayList<String>();

  citiesSource.add("Istanbul");
  citiesSource.add("Ankara");
  citiesSource.add("Izmir");
  citiesSource.add("Antalya");
  citiesSource.add("Bursa");
//  citiesTarget.add("T1");


  cities = new DualListModel<String>(citiesSource, citiesTarget);
   }

   public DualListModel<String> getCities() {
      return cities;
   }
   public void setCities(DualListModel<String> cities) {
      this.cities = cities;
   }
   public void displayList(){

     System.out.println("values in list are" +cities.getTarget());


   }


}

primefaces如何从选项列表中检索更改的值

3 个答案: