数据显示

用struts2  为什么从数据库中读取的数据在页面中无法显示
从数据库中读取问题信息的代码如下：
package teachinves.db;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;import teachinves.bean.question;
import teachinves.bean.teacher;
import DBConn.Odb;public class lessonDAO {
   Odb odb=new Odb();
   
     public List<question> allquestion(){
   List<question> list=new ArrayList<question>();
   String sql="select * from QUESTION_LIST";
   try{
   PreparedStatement ps=odb.getConnection().prepareStatement(sql);
   ResultSet rs=ps.executeQuery(sql);
   while(rs.next()){
   question que=new question();
   que.setVquestionid(rs.getString("vquestionid"));
   que.setVquestiontitle(rs.getString("vquestiontitle"));
   que.setVquestioncontent(rs.getString("vquestioncontent"));
   que.setDquestiontime(rs.getDate("dquestiontime"));
   que.setVlessonid(rs.getString("vlessonid"));
   que.setVteacherid(rs.getString("vteacherid"));
   que.setVquizstudentid(rs.getString("vquizstudentid"));
   que.setVlabelid(rs.getString("vlabelid"));
   que.setIstateid(rs.getInt("istateid"));
   que.setVquestionstatid(rs.getString("vquestionstatid"));
   que.setVmerat(rs.getInt("vmerat"));
   que.setVdescription(rs.getString("vdescription"));
   que.setVevaluate(rs.getString("vevaluate"));
   que.setVsuggestion(rs.getString("vsuggestion"));
       list.add(que);

   
   }
   }catch (Exception e){
   e.printStackTrace();
   }finally{
   odb.close();
   }
return list;
   
   }
   }
其中的action代码如下：
package teacher.action;import java.util.ArrayList;
import java.util.List;import javax.management.Query;import DBConn.test;import com.bean.statistic;
import com.opensymphony.xwork2.ActionSupport;import teachinves.bean.question;
import teachinves.bean.teacher;
import teachinves.db.lessonDAO;
import teachinves.db.statisticDao;public class QuestionAction extends ActionSupport {
        private static final String SUCCESS = null;
      private List<question> allquestion;
  public List<question> getAllquestion() {
return allquestion;
} public void setAllquestion(List<question> allquestion) {
this.allquestion = allquestion;
}
        public String excute(){
         lessonDAO ld=new lessonDAO();
       
         ld.allquestion();
        
         return SUCCESS;
        }
          
}struts.xml文件配置：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.1//EN" "http://struts.apache.org/dtds/struts-2.1.dtd">
<struts>
   <include file="struts-default.xml"></include> 
    <package name="struts2" extends="struts-default" >    
       <action name="allquestion" class="teacher.action.QuestionAction" method="getAllquestion">
         <result name="success">/index.jsp</result>
       </action>
    </package>
</struts>    
最后jsp页面：
<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<%@ taglib uri="/struts-tags" prefix="s" %>
<%@ page import="DBConn.Odb" %>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'index.jsp' starting page</title>
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">    
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<!--
<link rel="stylesheet" type="text/css" href="styles.css">
-->
  </head>
  
  <body>
   <s:iterator value="allquestion" status="st">
     <ul class="allul">
       <li class="allli"><s:property value="vquestionid"/></li>
       <li class="allli"><s:property value="vquestiontitle"/></li>
     </ul>
     </s:iterator>
     
  </body>
</html>数据可以读出来，但不知道为什么不能在页面中显示