安装MySQL数据库，建立用户表 uid uname upwd 并插入3条数据 2.制作jsp登录页面 index.jsp 提交到ok.jsp，使用jdbc连数据库，判断输入的用户名密码是否存在 3.如果存在，把用户名保存，跳转到yes.jsp
数据库
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<html>
<body>
<form action="ok.jsp" method=post>
用户名： <input type="text" name="uname" /> <br> 密 码 ： <input
type="text" name="upwd" /><br> 验证码： <input type="text"
name="yzm" /> 11+30=?<br> <input type="submit" name="dl"
value="登录" /> <br>
</form>
<% %>
<script> //弹窗提示
alert('输入密码或用户名错误');
</script>
</body>
</html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page import="java.sql.*"%>
<html>
<body>
<%
request.setCharacterEncoding("utf-8");
String name = request.getParameter("uname");
String pwd = request.getParameter("upwd");
String yz = request.getParameter("yzm");
//request.getRequestDispatcher("index.jsp").forward(request,response);
PreparedStatement pre = null;
Connection con = null;
Statement sql;
ResultSet rs;
request.setCharacterEncoding("utf-8");
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (Exception e) {
out.print("<h1>加载错误" + e);
}
String user = "root";
String password = "root";
con = DriverManager.getConnection(
"jdbc:mysql://127.0.0.1:3306/mysql", user, password);
try {
sql = con.createStatement();
String SQLL = "select * from sjk where uname=? and upwd=?";
pre = con.prepareStatement(SQLL);
pre.setString(1, name);
pre.setString(2, pwd);
rs = pre.executeQuery();
if (rs.next()) {
String na = rs.getString(2);
session.setAttribute("uname", na);
response.sendRedirect("yes.jsp");
} else {
response.sendRedirect("index.jsp");
}
} catch (SQLException e) {
out.print("<h1>查询错误" + e);
}
%>
</body>
</html>
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%> <html> <body> 欢迎 <%=session.getAttribute("uname")%> 来到你的世界！ </body> </html>
