前端页面：
用户登录首页：
<!doctype html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport"content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0"><meta http-equiv="X-UA-Compatible" content="ie=edge"><title>用户登录首页</title>
</head><body>登录人: <span id="loginUser"></span><script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.4/jquery.min.js"></script><script></script>
</body></html>登录页面：
<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><title>登录页面</title>
</head><body><h1>用户登录</h1>用户名：<input name="userName" type="text" id="userName"><br>密码：<input name="password" type="password" id="password"><br><input type="button" value="登录" onclick="login()"><script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.4/jquery.min.js"></script><script>function login() {}</script>
</body></html>
后端代码：
@RestController
@RequestMapping("/user")
public class UserController {@RequestMapping("/login")public boolean login(String userName, String password , HttpSession session){if (userName==null || userName.length()==0 || password==null || password.length()==0){return false;}if ("admin".equals(userName) && "admin".equals(password)){//设置sessionsession.setAttribute("username","admin");return true;}return false;}@RequestMapping("/getUserInfo")public String getUserInfo(HttpServletRequest request){//从session获取登录用户HttpSession session = request.getSession(false);String userName=null;if (session !=null){userName = (String)session.getAttribute("username");}return "当前登录用户:"+userName;}
}前端代码：
<!DOCTYPE html>
<html lang="en"><head><meta charset="UTF-8"><title>登录页面</title>
</head><body>
<h1>用户登录</h1>
用户名：<input name="userName" type="text" id="userName"><br>
密码：<input name="password" type="password" id="password"><br>
<input type="button" value="登录" onclick="login()"><script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.4/jquery.min.js"></script>
<script>function login() {console.log("登录")$.ajax({url:"user/login",type:"post",data:{"userName":$("#userName").val(),"password":$("#password").val()},success:function(result){if(result){location.href="/index.html";//location.assign();}else{alert("密码错误！");}}});}</script>
</body></html>
<!doctype html>
<html lang="en"><head><meta charset="UTF-8"><meta name="viewport"content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0"><meta http-equiv="X-UA-Compatible" content="ie=edge"><title>用户登录首页</title>
</head><body>
登录人: <span id="loginUser"></span><script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.4/jquery.min.js"></script>
<script>//页面加载时，就去调用后端请求$.ajax({url:"/user/getUserInfo",type:"get",success:function(username){$("#loginUser").text(username);}});</script>
</body></html>
成果展示：
简洁版用户登录
