求助。。。rs cannot be resolved错误怎么办

[zfrmypicture]

package com.gdupt.servlet;

import java.io.IOException;
import java.sql.*;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.gdupt.db.DataAccess;
import com.sun.org.apache.regexp.internal.RE;

public class LoginServlet extends HttpServlet {





@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
//获得用户输入
String userno=req.getParameter("userno");
String userpsw=req.getParameter("userpsw");
//数据库连接对象
Connection conn=DataAccess.getConnection();

String sql="select * from tbluser where userno=? and userpsw?";


try{
//创建查询对象
PreparedStatement prest= conn.prepareStatement(sql);
prest.setString(1, userno);
prest.setString(2, userpsw);



//处理查询结果
if(rs.next()) {
PrintWriter out=resp.getWriter();
out.print("Welcome");

} else {
resp.sendRedirect("index.jsp");
}
rs.close();
prest.close();
}catch (SQLException e) {
resp.sendRedirect("index.jsp");
}

}
}

[zfrmypicture]

嗯，对，但是改了之后，剩下PrintWriter还是有问题啊？
//处理查询结果
if(rs.next()) {
PrintWriter out=resp.getWriter();
out.print("Welcome");

[ylovep]

userpsw? 这个拼写错了啊

[wang7535067]

rs都没看到定义。还有这里and userpsw?";
也有问题，
应该写成这样String sql="select * from tbluser where userno=? and userpsw=?";

然后在prest.setString(2, userpsw);下面写
ResultSet rs=prest.executeQuery();

[凡人之玲珑]

2 楼正解

[wang7535067]

if(rs.next()) {
PrintWriter out=resp.getWriter();
out.print("Welcome");
改成
if(rs.next()) {
out.print(rs.getString(1));
out.print(rs.getString(2));
out.print("Welcome");

[zfrmypicture]

改成if(rs.next()) {
out.print(rs.getString(1));
out.print(rs.getString(2));
out.print("Welcome");
又变成out有问题了“out cannot be resolved”怎么办 啊？？？

[「已注销」]

[Quote=引用 2 楼 wang7535067 的回复:]

rs都没看到定义。还有这里and userpsw?";
也有问题，
应该写成这样String sql="select * from tbluser where userno=? and userpsw=?";

然后在prest.setString(2, userpsw);下面写
ResultSet rs=prest.executeQuery();
[/Quote]
楼主看这个

[凡人之玲珑]

重新贴 改之后的代码。。

[zfrmypicture]

package com.gdupt.servlet;

import java.io.IOException;
import java.sql.*;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.gdupt.db.DataAccess;
import com.sun.org.apache.regexp.internal.RE;

public class LoginServlet extends HttpServlet {





@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
//获得用户输入
String userno=req.getParameter("userno");
String userpsw=req.getParameter("userpsw");
//数据库连接对象
Connection conn=DataAccess.getConnection();

String sql="select * from tbluser where userno=? and userpsw=?";


try{
//创建查询对象
PreparedStatement prest= conn.prepareStatement(sql);
prest.setString(1, userno);
prest.setString(2, userpsw);
ResultSet rs=prest.executeQuery();




//处理查询结果
if(rs.next()) {
out.print(rs.getString(1));
out.print(rs.getString(2));
out.print("Welcome");

} else {
resp.sendRedirect("index.jsp");
}
rs.close();
prest.close();
}catch (SQLException e) {
resp.sendRedirect("index.jsp");
}

}
}
错误是“out cannot be resolved”！！！

[forgetsam]

这是个P错误，这是最基本的变量声明赋值都没弄明白。

out是什么，上文里有吗？你要写jsp，out应该是response的Writer

你是不是只会复制粘贴？“人家粘了好使，我粘了不好使”，连复制粘贴你都粘不全。

[zfrmypicture]

楼上大哥所言甚是，小弟确实要恶补下基础。。。。