jsp查询ORACLE数据时，怎麽在页面上显示，帮忙分析我的错误原因？

代码
<%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.sql.*"%>
<html>
<body>
<%Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();
String url="jdbc:oracle:thin:@localhost:1521:mbl";
String user="system";
String password="manager";
Connection conn= DriverManager.getConnection(url,user,password);
Statement stmt=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
String sql="select * from test";
ResultSet rs=stmt.executeQuery(sql);
while(rs.next()) {%>
a<%=rs.getString(1)%>
b<%=rs.getString(2)%>
<%}%>
<%out.println("AAA");%>
<%rs.close();
stmt.close();
conn.close();
%>
</body>
</html>


在WEBLOGIC61运行时错误
Error 500--Internal Server Error
From RFC 2068 Hypertext Transfer Protocol -- HTTP/1.1:
10.5.1 500 Internal Server Error
The server encountered an unexpected condition which prevented it from fulfilling the request.