javaweb--简单的login用户登录-蒲公英云

javaweb--简单的login用户登录

简单jsp前后台交互实现登录无数据库校验！

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2021/9/7 0007
  Time: 16:49
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>登录</title>
</head>
<body>
<form method="post" action="loginServlet">
    姓名: <input name="uname" type="txt"> <br>
    密码: <input name="upwd" type="password"><br>
    <button>提交</button>
    <%--获取后台设置在作用域中的数据并显示--%>
    <span style="color: red;font-size: 12px"><%=request.getAttribute("msg")%></span>
</form>
</body>
</html>

loginServlet.class

package com.liu.controller;
import sun.util.resources.cldr.ml.CalendarData_ml_IN;
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 java.io.IOException;
@WebServlet("/loginServlet")
public class loginServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
      //设置客户端编码
        request.setCharacterEncoding("UTF-8");
        //接受客户端传递的参数
        String uname = request.getParameter("uname");
        String upwd = request.getParameter("upwd");
        //判断参数是否为空
        if(uname == null || "".equals(uname.trim())){
            //提示用户信息
            request.setAttribute("msg","用户姓名不能为空！");
            //跳转回登录请求转发
            request.getRequestDispatcher("login.jsp").forward(request,response);
            return;
        }
        if(upwd == null || "".equals(upwd.trim())){
            //提示用户信息
            request.setAttribute("msg","用户密码不能为空！");
            //跳转回登录请求转发
            request.getRequestDispatcher("login.jsp").forward(request,response);
            return;
        }
        //判断账号密码是否正确 uname = admin ；admin = admin
        if (!"admin".equals(uname)||!"admin".equals(upwd)){
            request.setAttribute("msg","登录失败！");
            request.getRequestDispatcher("login.jsp").forward(request,response);
            return;
        }
        //登录成功
        //设置登录信息到session作用域
        request.getSession().setAttribute("uname",uname);
        //跳转到首页
       response.sendRedirect("index.jsp");
    }
}

index.jsp

<%--
  Created by IntelliJ IDEA.
  User: Administrator
  Date: 2021/9/7 0007
  Time: 16:14
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
  <head>
    <title>登录</title>
  </head>
  <body>
  <h2>欢迎<%=session.getAttribute("uname")%>登录！</h2>
  </body>
</html>