使用环境：
winxp
Tomcat/5.5.26
j2sdk 1.5
SQL server 2000 打了SP4补丁
安装了Microsoft SQL Server 2000 Driver for JDBC sp3
WEB-INF\lib下也放了jar包。平常的数据库连接都可以。
这是个书中的例子，做时出现问题：
<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" %>
<jsp:useBean id="conn" scope="page" class="com.ConnDB"/>
<%
String sql="select * from tb_branch";
ResultSet rs=conn.executeQuery(sql);
%>
<html>
<head>
<title>选择所有列 </title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<link href="CSS/style.css" rel="stylesheet">
</head>
<body>
<table width="600" height="201" border="0" align="center" cellpadding="0" cellspacing="0" bgcolor="#FFFFFF">
<tr>
<td height="201" valign="top">
<table width="100%" height="77" border="1" cellpadding="0" cellspacing="0" bordercolor="#FFFFFF" bordercolordark="#FFFFFF" bordercolorlight="#666666">
<tr style="padding:5px;">
<td height="24" colspan="4" align="center" bgcolor="#CCCCCC">≡≡≡ 部门全部信息 ≡≡≡ </td>
</tr>
<tr>
<td width="18%" height="27" align="center"> ID号 </td>
<td width="36%" align="center">部门名称 </td>
<td width="20%" align="center">联系电话 </td>
<td width="8%" align="center">备注 </td>
</tr>
<%
try{
while(rs.next()){
%>
<tr style="padding:5px;">
<td height="24" align="center"> <%=rs.getInt("id")%> </td>
<td align="center"> <%=rs.getString("name")%> </td>
<td align="center"> <%=rs.getString("tel")%> </td>
<td align="center"> <%=rs.getString("memo")%> </td>
</tr>
<%
}
}catch(Exception e){}
%>
</table> </td>
</tr>
</table>
</body>
</html>
错误如下：
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: Unable to load class for JSP
org.apache.jasper.JspCompilationContext.load(JspCompilationContext.java:599)
org.apache.jasper.servlet.JspServletWrapper.getServlet(JspServletWrapper.java:137)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:314)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:329)