JSF ajax监听器不适用于下拉列表

Question

我正在尝试为下拉列表添加ajax，我在xhtml中添加了以下代码，但是一旦发生更改，就不会调用listner。

XHTML代码：

<h:selectOneMenu
                            value="#{loginBean.dropDownValue}" itemValue="#{dropDownValue}">
                            <f:selectItem itemValue="****select***" />
                            <f:selectItems value="#{loginBean.testDropDown}"/>
                             <f:ajax event="change" listner="#{loginBean.changeDropDownOne}" render="testDropDownTwoValue" />
                        </h:selectOneMenu>

bean中的方法：

public List<SelectItem> changeDropDownOne() {
        System.out.println("$$$$$$$$$$");
        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;
    }