麻烦讲解下这段JSP代码是什么意思？

这个很简单吧
String sqlxtgg="select * from dx where leibie='系统公告'";
——准备SQL查询语句，就是选择出所有类别为系统公告的记录
ResultSet RS_resultxtgg=connDbBean.executeQuery(sqlxtgg);
——执行查询，并得到结果数据集
while(RS_resultxtgg.next()) {
—— 用next()循环（或称滚动）该结果集
out.print(RS_resultxtgg.getString("content"));
——获取content字段的内容，并输出
}

在myeclipse中这行显示有错
ResultSet RS_resultxtgg=connDbBean.executeQuery(sqlxtgg);
是怎么回事呢

检查一下SQL语句有没有问题啊，比如“系统公告”的引号应该是英文的，别弄成中文了

我觉得应该如果是ResultSet这里报错就应该是没导包 java.sql.ResultSet如果是connDbBean这里报错的话应该是在这之前没声明这个变量. 其实我也不太懂，我也是初学者，坐等一楼来解答......

<%@ page language="java" contentType="text/html; charset=gb2312"
pageEncoding="gb2312" session="true" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>Insert title here</title>
<SCRIPT language=javascript1.2>
function showsubmenu(sid)
{
whichEl = eval("submenu" + sid);
if (whichEl.style.display == "none")
{
eval("submenu" + sid + ".style.display=\"\";");
}
else
{
eval("submenu" + sid + ".style.display=\"none\";");
}
}
</SCRIPT><META content="MSHTML 6.00.2800.1106" name=GENERATOR>
<style type="text/css">

</style>
</HEAD>
<table id="__01" width="220" height="532" border="0" cellpadding="0" cellspacing="0">
              <tr>
                <td colspan="2"><img src="qtimages/img_02_01_01.gif" width="220" height="3" alt=""></td>
              </tr>
              <tr>
                <td width="9" height="100%" rowspan="3" background="qtimages/img_02_01_02.gif"> </td>
                <td width="211" height="150" valign="middle" background="qtimages/img_02_01_03.gif">
                  <p> </p>
  <%

if((String)request.getSession().getAttribute("username")==null || (String)request.getSession().getAttribute("username")=="")  //判断用户是否已经登陆，如果没有，则给出登陆框，如果有则显示当前用户信息
{
%>
                  <table width="94%" height="103" border="0" align="center" cellpadding="0" cellspacing="0"><form name="form1" method="post" action="userlog_post.jsp">
                    <tr>
                      <td>用户名:</td>
                      <td><input name="username" type="text" id="username" size="18"></td>
                    </tr>
                    <tr>
                      <td>密码:</td>
                      <td><input name="pwd1" type="password" id="pwd1" size="18"></td>
                    </tr>
                    <tr>
                      <td>权限：</td>
                      <td><select name="cx" id="cx">
                        <option value="注册会员">注册会员</option>
                        <option value="旅行社">旅行社</option>
                      </select></td>
                    </tr>
                    <tr>
                      <td> </td>
                      <td><input type="image" name="imageField" src="qtimages/1.gif">
                        <img src="qtimages/2.gif" width="68" height="24" onClick="javascript:form1.reset();"></td>
                    </tr> </form>
                  </table>

   <%}
    else
    {
     %>
  <table width="94%" height="103" border="0" align="center" cellpadding="0" cellspacing="0">
                    <tr>
                      <td width="40%">用户名:</td>
                      <td width="60%"><%=request.getSession().getAttribute("username") %></td>
                    </tr>
                    <tr>
                      <td>您的角色:</td>
                      <td><%= request.getSession().getAttribute("cx")%></td>
                    </tr>
                    <tr>
                      <td align="center"><img src="qtimages/5.gif" width="68" height="24" onClick="javascript:location.href='main.jsp';"></td>
                      <td align="center">
                        <img src="qtimages/4.gif" width="68" height="24" onClick="javascript:location.href='logout.jsp';"></td>
                    </tr>
                  </table>

   <%} %>
                </td>
              </tr>
              <tr>
                <td height="183"><table id="__01" width="211" height="183" border="0" cellpadding="0" cellspacing="0">
                  <tr>
                    <td width="211" height="29" background="qtimages/img_02_01_04_01.gif"><table width="88%" border="0" align="center" cellspacing="0">
                      <tr>
                        <td width="71%"><span class="unnamed2_14 STYLE2 STYLE1">系统公告</span></td>
                        <td width="29%"> </td>
                      </tr>
                    </table></td>
                  </tr>
                  <tr>
                    <td width="211" height="154" background="qtimages/img_02_01_04_02.gif"><marquee border="0" direction="up" height="130" onMouseOut="start()" onMouseOver="stop()"
                scrollamount="1" scrolldelay="50"><TABLE cellSpacing=5
      cellPadding=0 width="92%" align=center
            border=0><TBODY><TR><TD><P>
<%
String sqlxtgg="select * from dx where leibie='系统公告'";
ResultSet RS_resultxtgg=connDbBean.executeQuery(sqlxtgg);
while(RS_resultxtgg.next())
{
out.print(RS_resultxtgg.getString("content"));
}
%>
</P></TD></TR></TBODY></TABLE></marquee></td>
                  </tr>
                </table></td>
              </tr>
              <tr>
                <td height="183"><table id="__01" width="211" height="183" border="0" cellpadding="0" cellspacing="0">
                  <tr>
                    <td width="211" height="29" background="qtimages/img_02_01_04_01.gif"><table width="88%" border="0" align="center" cellspacing="0">
                        <tr>
                          <td width="71%"><span class="unnamed2_14 STYLE2 STYLE1">友情连接</span></td>
                          <td width="29%"> </td>
                        </tr>
                    </table></td>
                  </tr>
                  <tr>
                    <td width="211" height="154" background="qtimages/img_02_01_04_02.gif"><table width="92%" border="0" align="center" cellpadding="0" cellspacing="0">
                      <%
        String sql2="";
  sql2="select top 5 * from youqinglianjie where 1=1";
  sql2=sql2+" order by id desc";
ResultSet RS_result2=connDbBean.executeQuery(sql2);
String wangzhanmingcheng="";String wangzhi="";
//int i=0;
while(RS_result2.next()){
//i=i+1;
wangzhanmingcheng=RS_result2.getString("wangzhanmingcheng");wangzhi=RS_result2.getString("wangzhi");         %>
                      <tr valign="middle">
                        <td width="83%" height="24" align="left"><img src="qtimages/3.gif" border="0"> <a href="<%= wangzhi%>" class="b" target="_blank"><%= wangzhanmingcheng%></a></td>
                      </tr>

                      <%} %>

                    </table></td>
                  </tr>
                </table></td>
              </tr>

              <tr>
                <td height="10" colspan="2" background="qtimages/img_02_01_07.gif"> </td>
              </tr>
            </table>
            </html>

你代码写的好乱啊，后台数据库查询怎么都写在前台了。而且ResultSet RS_result2=connDbBean.executeQuery(sql2); 这个变量connDbBean我从头到尾没看到定义，请你解释下

数据库连接的函数connDbBean没有看到。如果没有有参考下面的函数：import java.sql.*;
import java.lang.*;public class connDbBean {
String sDBDriver = "oracle.jdbc.driver.OracleDriver";
String sConnStr="jdbc:oracle:thin:@localhost:1521:myorcl"; //你的数据库连接地址和sid
Connection conn = null;
ResultSet rs = null; public connDbBean() {
try {
Class.forName(sDBDriver);
} catch (java.lang.ClassNotFoundException e) {
System.err.println("sql_data():" + e.getMessage());
}
} public ResultSet executeQuery(String sql) {
rs = null;
try {
conn = DriverManager.getConnection(sConnStr, "oraName", "oraPswd");
Statement stmt = conn.createStatement();
rs = stmt.executeQuery(sql);
} catch (SQLException ex) {
System.err.println("connDbBean.executeQuery:" + ex.getMessage());
}
return rs;
}
}

<%@ page language="java" contentType="text/html; charset=gb2312"
pageEncoding="gb2312" session="true" %>
<%@ page language="java" import="java.sql.*" %>
<jsp:useBean id="connDbBean" scope="page" class="db.db"/>
在你的jsp头，添加后面的两句 db.db 为你的连接数据库的java类的包名.类名
希望能帮到你

调试易

麻烦讲解下这段JSP代码是什么意思？

解决方案 »