华润混凝土有限公司:帮忙看 下这个JSP提示错误是什么意思,原因在哪?下边附有java文件和JSP代码

来源:百度文库 编辑:中科新闻网 时间:2024/04/29 17:25:44
An error occurred at line: 11 in the jsp file: /view.jsp

Generated servlet error:
C:\Tomcat 5.0\work\Catalina\localhost\exam\org\apache\jsp\view_jsp.java:58: cannot resolve symbol
symbol : class ResultSet
location: class org.apache.jsp.view_jsp
ResultSet rs=vote.executQuery("select * from vote");
^

An error occurred at line: 11 in the jsp file: /view.jsp

Generated servlet error:
C:\Tomcat 5.0\work\Catalina\localhost\exam\org\apache\jsp\view_jsp.java:58: cannot resolve symbol
symbol : method executQuery (java.lang.String)
location: class lei.voteconn
ResultSet rs=vote.executQuery("select * from vote");

调用的JAVA文件。
我不知道怎么个修改才能让我能通过页面访问数据库并且对数据库进行填加,修改,删除等操作
package lei;
import java.sql.*;
public class voteconn
{
Connection con;
ResultSet rs;
public voteconn()
{ try{Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
}
catch(ClassNotFoundException e){
System.err.println(e.getMessage());
}
}
public ResultSet executeQuery(String sql)
{ try{con=DriverManager.getConnection("jdbc:odbc:research","","");
Statement stm=con.createStatement();
rs=stm.executeQuery(sql);
}
catch(SQLException ex){
System.err.println(ex.getMessage());
}
return rs;
}
public int executeUpdate(String sql)
{ int result=0;
try{con=DriverManager.getConnection("jdbc:odbc:research","","");
Statement stmt=con.createStatement();
result=stmt.executeUpdate(sql);
}
catch(SQLException ex){
System.err.println(ex.getMessage());
}
return result;
}
}

JSP代码
<%@ page contentType="text/html;charset=GB2312"%>
<%@ page import="lei.voteconn" %>
<jsp:useBean id="vote" class="lei.voteconn" scope="page" />
<% int tot_num=0;int tmp_num=0; %>
<html>
<head>
<title>调查问卷结果</title>
</head>
<body>
<table width="90%" border="0" cellpadding="3" cellspacing="2">
<% ResultSet tmpRs=vote.executeQuery("select sum(num) AS totalnum from vote");
tmpRs.next();
tot_num=tmpRs.getInt("totalnum");
tmpRs.close();
ResultSet rs=vote.executQuery("select * from vote");
int i=1;
while(rs.next())
{%>
<tr bgcolor="#99ccff">
<td>选项<%= i %>:<%= rs.getString("content") %></td>
</tr>
<tr>
<% tmp_num=rs.getInt("num"); %>
<td>投票率:<img src="back.gif" width="<%= Math.floor(tmp_num*200/tot_num)%>" height="8">
<%= Math.floor(tmp_num*100/tot_num)%>%[得:<%= tmp_num %>票 共<%= tot_num %>票]
</td>
</tr>
<% i++;
}%>
</table>
<% rs.close(); %>
</body>
</html>

<% ResultSet tmpRs=vote.executeQuery("select sum(num) AS totalnum from vote");
用了ResultSet你必须在jsp页面里引入java.sql.*类包呀!在<%@ page import="lei.voteconn" %>
下加<%@ page import="java.sql.*" %>就可以了