jsp 调用 javabean 出现下列错误

Question

意思是说
sqlbean.executeQuery("SELECT * FROM CARD_OPERATOR_TAB")返回的是一个void
而你是对一个ResultSet赋值，所以会出错 

Answer 1

是不是由于数据库为连接上，才返回一void值，我的意思是通过JAVABEAN 连接数据库，并读取值

Answer 2

jsp 程序
 <%@ page language="java" import="client.sql_data,java.sql.*" %>
<jsp:useBean id="sqlbean" scope="session" class="client.sql_data" />
<%
  
 ResultSet rs=sqlbean.executeQuery("SELECT * FROM CARD_OPERATOR_TAB");
 while (rs.next()){%><%=rs.getString(OPER_ID)%>
  <%=rs.getString(OPER_NAME)%>
  <%=rs.getString(CITY_CODE)%>
  <table boder=1 whith=80%>
  <tr>
  <td width=30%>ID:</td><td width=70%><%=OPER_ID%>
  </tr>
  <tr>
  <td width=30%>NAME:</td><td width=70%><a herf="<%=OPER_NAME%>"><%=OPER_NAME%></a></td>     
  </tr>
  <tr>
  <td width=30%>CITY_CODE:</td><td width=70%><%=CITY_CODE%></TD>
  <tr>
    
<%}
rs.close();
%>javabean程序
package client;
import oracle.jdbc.*;
import java.io.*;
import java.sql.*;public class sql_data
{
      String url="jdbc:oracle:thin:@202.107.51.243:1521:orcl";
      String userName="card";
      String passWord="card";
      Connection conn=null;
      ResultSet rs;
       public sql_data()
        {
          try
            {
              Class.forName ("oracle.jdbc.driver.OracleDriver");
            }
           catch(java.lang.ClassNotFoundException e)
             {
               System.err.println("sql_data():"+e.getMessage());
             }
         }
       public ResultSet executeQuery(String sql)
       {
       rs=null;
       try
       {
       conn = DriverManager.getConnection(url,userName,passWord);
       Statement stmt=conn.createStatement();
       rs=stmt.executeQuery(sql);
       }
       catch(SQLException ex)
       {
       System.err.println("sql_data.executeQuery"+ex.getMessage());
       }
      return rs;
       }}
以上程序有问题吗？

Answer 3

<%=rs.getString(OPER_ID)%>
<%=rs.getString(OPER_NAME)%>
<%=rs.getString(CITY_CODE)%>
应该是漏了标点吧？改为：
<%=rs.getString("OPER_ID")%>
<%=rs.getString("OPER_NAME")%>
<%=rs.getString("CITY_CODE")%>