<%--
Created by IntelliJ IDEA.
User: Dell
Date: 2021/4/10
Time: 14:34
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<form action="dologin.jsp" method="post">
用户名：<input type="text" name="username"/><br/>
密码：<input type="password" name="password"/><br/>
验证码：<input type="text" name="inputVcode"/><img src="/WebProject_war_exploded/createCode"><br/>
<input type="submit" value="登录">
</form>
</body>
</html>
dologin.jsp
<%@ page import="java.sql.*" %><%--
Created by IntelliJ IDEA.
User: Dell
Date: 2021/4/10
Time: 14:38
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<%
String uname = request.getParameter("username");
String upwd = request.getParameter("password");
String inputVcode = request.getParameter("inputVcode").toLowerCase();
String realInputVcode =(String) session.getAttribute("codes");
String realUname="";
String reaslPassword = "";
Class.forName("com.mysql.jdbc.Driver");
Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/mysql","root","root");
PreparedStatement preparedStatement =connection.prepareStatement("SELECT * FROM dl where uname = ?");
preparedStatement.setString(1,uname);
ResultSet rs = null;
try {
rs = preparedStatement.executeQuery();
} catch (SQLException e) {
e.printStackTrace();
}
//如果有数据，rs.next()返回true
while(rs.next()){
realUname = rs.getString("uname");
reaslPassword = rs.getString("upwd");
}
if(uname.equals(realUname)&&upwd.equals(reaslPassword)&&inputVcode.equals(inputVcode)){
HttpSession httpSession = request.getSession();
httpSession.setAttribute("username",uname);
httpSession.setAttribute("password",upwd);
response.sendRedirect("success.jsp");
}else {
response.sendRedirect("login.jsp");
}
%>
</body>
</html>
success.jsp
<%--
Created by IntelliJ IDEA.
User: Dell
Date: 2021/4/10
Time: 15:20
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<%
String username =(String) session.getAttribute("username");
if(username==null){
response.sendRedirect("login.jsp");
}
%>
欢迎你<%=username %>
</body>
</html>
package com.dx.yzm;
import cn.dsna.util.images.ValidateCode;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;
@WebServlet(name = "CreateCodeController",value = "/createCode")
public class CreateCodeController extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//1.创建验证码图片
ValidateCode code = new ValidateCode(200,30,4,20);
String codes = code.getCode();
HttpSession session = request.getSession();
session.setAttribute("codes",codes);
//2.验证码图片响应给客户端
code.write(response.getOutputStream());
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doPost(request,response);
}
}