jsf 下拉列表错误

harkue 2008-07-23 05:45:06

我的Bean：

Person.java



import java.util.ArrayList;

import java.util.List;



import javax.faces.event.ValueChangeEvent;

import javax.faces.model.SelectItem;



public class Person {

	private String name = "test";



	private String value = "test";



	private List names = new ArrayList();



	private List values = new ArrayList();

	

	// 这个方法什么也没写,主要就是刷新页面用

	public void onChangeName(ValueChangeEvent event) {

	}



	public String getName() {

		return name;

	}



	public void setName(String name) {

		this.name = name;

	}



	public List getNames() {

		names.add(new SelectItem("bb","bb"));

		names.add(new SelectItem("cc","cc"));

		return names;

	}



	public void setNames(List names) {

		this.names = names;

	}



	public String getValue() {

		return value;

	}



	public void setValue(String value) {

		this.value = value;

	}



	public void setValues(List values) {

		this.values = values;

	}



	// 在values的getValues方法中来处理数据

	public List getValues() {

		// 设置初始值

		// 当name取值为bb时,赋值,此处可以从数据库取值

		if (name.equals("bb"))

			values.add("BB");

		// 当name取值为cc时,赋值,此处可以从数据库取值

		if (name.equals("cc"))

			values.add("CC");



		return values;

	}



}

页面person.jsp:



<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h"%>

<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f"%>

<%@ page language="java" pageEncoding="gb2312"%>



<html>

<head>

<title>Person</title>

</head>



<body>

<f:view>

	<h:form>

		<table border="1">

			<tr>

				<td><h:selectOneMenu value="#{person.name}"

					onchange="this.form.submit();"

					valueChangeListener="#{person.onChangeName}">

					<f:selectItems value="#{person.names}"/>

				</h:selectOneMenu></td>

			</tr>

		</table>

	</h:form>

</f:view>

</body>

</html>

配置文件faces-config.xml：
<managed-bean>
<managed-bean-name>person</managed-bean-name>
<managed-bean-class>de.laliluna.tutorial.library.Person</managed-bean-class>
<managed-bean-scope>session</managed-bean-scope>
</managed-bean>

然后一直报错：
javax.servlet.ServletException: javax.servlet.jsp.JspException: "{2}" Conversion Error setting value ''{0}'' for ''{1}''.
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:821)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:758)
org.apache.jsp.person_jsp._jspService(person_jsp.java:81)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:322)
com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:147)
com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:87)
com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:200)
com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:117)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:198)

root cause

java.lang.IllegalArgumentException: "{2}" Conversion Error setting value ''{0}'' for ''{1}''.
com.sun.faces.util.Util.getSelectItems(Util.java:610)
com.sun.faces.renderkit.html_basic.MenuRenderer.getOptionNumber(MenuRenderer.java:488)
com.sun.faces.renderkit.html_basic.MenuRenderer.renderSelect(MenuRenderer.java:465)
com.sun.faces.renderkit.html_basic.MenuRenderer.encodeEnd(MenuRenderer.java:430)
javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:712)
javax.faces.webapp.UIComponentTag.encodeEnd(UIComponentTag.java:616)
javax.faces.webapp.UIComponentTag.doEndTag(UIComponentTag.java:539)
com.sun.faces.taglib.html_basic.SelectOneMenuTag.doEndTag(SelectOneMenuTag.java:505)
org.apache.jsp.person_jsp._jspx_meth_h_selectOneMenu_0(person_jsp.java:171)
org.apache.jsp.person_jsp._jspx_meth_h_form_0(person_jsp.java:138)
org.apache.jsp.person_jsp._jspx_meth_f_view_0(person_jsp.java:107)
org.apache.jsp.person_jsp._jspService(person_jsp.java:71)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.sun.faces.context.ExternalContextImpl.dispatch(ExternalContextImpl.java:322)
com.sun.faces.application.ViewHandlerImpl.renderView(ViewHandlerImpl.java:147)
com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:87)
com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:200)
com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:117)
javax.faces.webapp.FacesServlet.service(FacesServlet.java:198)

网上搜索说，names为空值，但是显然不会啊·~~~~
到底是什么错误？

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