JSF级联下拉列表无法正常工作

Question

我正在尝试根据第一个列表中选择的值执行级联下拉列表，第二个列表中的值应该更改。下面是代码

XHTML：

<td width="42.5%" style="background-color: #DDEEF5;"><h:selectOneMenu
                            value="#{loginBean.dropDownValue}" itemValue="#{dropDownValue}">
                            <f:selectItem itemValue="****select***" />
                            <f:selectItems value="#{loginBean.testDropDown}"/>
                             <f:ajax event="change" listner="#{loginBean.getTestDropDownTwo}" render="testDropDownTwo" />
                        </h:selectOneMenu></td>
                    <td width="42.5%" style="background-color: #DDEEF5;">If model
                        users are shared with regulators please select the names(s) of the
                        regulator</td>
                </tr>
                <tr>
                    <td width="15%" background="red" style="background-color: #9ABDE7;">
                        <b>Regulator Area*</b>
                    </td>
                    <td width="42.5%" style="background-color: #DDEEF5;"><h:selectOneMenu
                            value="#{loginBean.dropDownTwoValue}" id="testDropDownTwo">
                            <f:selectItem itemValue="****select***" />
                            <f:selectItems value="#{loginBean.testDropDownTwo}" />
                        </h:selectOneMenu></td>

Bean代码：

/ **  * LoginBean.java  *  * /

package com.tutorial;

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

import javax.faces.model.SelectItem;
public class LoginBean
{
    private String name;
    private String password;
    private String dropDownValue;
    private String dropDownTwoValue;
    List<SelectItem> testDropDown = new ArrayList<SelectItem>();
    List<SelectItem> testDropDownTwo = new ArrayList<SelectItem>();

    public String getDropDownValue() {
        return dropDownValue;
    }


    public void setDropDownValue(String dropDownValue) {
        this.dropDownValue = dropDownValue;
    }


    public String getDropDownTwoValue() {
        return dropDownTwoValue;
    }


    public void setDropDownTwoValue(String dropDownTwoValue) {
        this.dropDownTwoValue = dropDownTwoValue;
    }


    public List<SelectItem> getTestDropDown() {
        testDropDown.add(new SelectItem("One"));
        testDropDown.add(new SelectItem("Two"));
        testDropDown.add(new SelectItem("Three"));
        testDropDown.add(new SelectItem("Four"));
        return testDropDown;
    }


    public List<SelectItem> getTestDropDownTwo() {
        String dp = getDropDownValue();
        if(dp != null) {
            System.out.println("**********************getTestDropDownTwo********************************"+dp);
            if(dp.equalsIgnoreCase("One")) {
                testDropDownTwo.add(new SelectItem("One - One"));
                testDropDownTwo.add(new SelectItem("One - Two"));
                testDropDownTwo.add(new SelectItem("One - Three"));
                testDropDownTwo.add(new SelectItem("One - Four"));
            } else if(dp.equalsIgnoreCase("Two")) {
                testDropDownTwo.add(new SelectItem("Two - One"));
                testDropDownTwo.add(new SelectItem("Two - Two"));
                testDropDownTwo.add(new SelectItem("Two - Three"));
                testDropDownTwo.add(new SelectItem("Two - Four"));
            }else if(dp.equalsIgnoreCase("Two")) {
                testDropDownTwo.add(new SelectItem("Three - One"));
                testDropDownTwo.add(new SelectItem("Three - Two"));
                testDropDownTwo.add(new SelectItem("Three - Three"));
                testDropDownTwo.add(new SelectItem("Three - Four"));
            }else {
                testDropDownTwo.add(new SelectItem("Four - One"));
                testDropDownTwo.add(new SelectItem("Four - Two"));
                testDropDownTwo.add(new SelectItem("Four - Three"));
                testDropDownTwo.add(new SelectItem("Four - Four"));
            }
        }
        return testDropDownTwo;
    }


    public void setTestDropDownTwo(List<SelectItem> testDropDownTwo) {
        this.testDropDownTwo = testDropDownTwo;
    }


    public void setTestDropDown(List<SelectItem> testDropDown) {

        this.testDropDown = testDropDown;
    }

    public String getName ()
    {
        return name;
    }


    public void setName (final String name)
    {
        this.name = name;
    }


    public String getPassword ()
    {
        return password;
    }


    public void setPassword (final String password)
    {
        this.password = password;
    }
    public String submit() {
        // Do your thing here.
        // ...
        System.out.println("****LoginBean***submit***");
        return "login";
    }
}

请在这方面帮助我