=====点下面JSP文件进入index.jsp=====
<%--投票系统首页--%>
<%@page contentType="text/html; charset=GBK" %>
<%@page language="java" import="java.sql.*" %>
<jsp:useBean id="connDbBean" scope="page" class="vote.VoteConn" />
<html>
<head>
<title>网上调查表</title>
<link rel="stylesheet" type="text/css" href="style.css">
</head>
<%
ResultSet rs = connDbBean.executeQuery("select * from vote");
%>
<body bgcolor="#ffffff">
<center>
<h2><font color="#0000FF">请您投票：</font></h2>
<Table border bgcolor="#00ffff">
<form action="vote.jsp">
<% while(rs.next()) { %>
<tr>
<td><input type="radio" name="type" value=<%=rs.getString("id")%>><%=rs.getString("note")%></td>
</tr>
<% }
rs.close();
%>
<tr align="center"><td><input type="submit" value="投票"></td></tr>
</form>
<tr><td><A href="details.jsp">查看投票</A></td></tr>
</Table>
</center>
</body>
</html>
=====出错页面：===== 地址：http://127.0.0.1:8080/j8/4/=====
HTTP Status 500 -
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:358)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:301)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:248)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
root cause
java.lang.NullPointerException
org.apache.jsp._4.index_jsp._jspService(index_jsp.java:69)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:133)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:311)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:301)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:248)
javax.servlet.http.HttpServlet.service(HttpServlet.java:856)
note The full stack trace of the root cause is available in the Tomcat logs.
Apache Tomcat/5.0.19
參考答案:一楼，你们老师是sb