现在多系统的登陆都采用单点登陆了，emmmm......后期再更单点登陆的，这次由于只是个小demo，所以我们采用Session和EL表达式实现登陆验证。
1.业务流程
用户在login登录页输入用户名密码----->使用用户名和密码登陆验证------>验证成功，跳转欢迎页/验证失败，重新输入提示。
2.数据库设计
这里就用到了一张表User表。
image.png
3.项目架构（MVC）
image.png
4.效果预览
预览.gif
5.代码实现
View层:
Login.jsp：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort()
+ path + "/";
%>
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="renderer" content="webkit">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
<title>法律法规管理系统</title>
<link rel="stylesheet" href="/public/frame/layui/css/layui.css">
<link rel="stylesheet" href="/public/frame/static/css/style.css">
</head>
<body background="/public/frame/static/image/1.jpg">
<div class="login-main">
<header class="layui-elip">
<h3 style="color: bisque">法律法规管理系统</h3>
</header>
<form class="layui-form">
<div class="layui-input-inline">
<input id="username" type="text" name="username" required lay-verify="required" placeholder="账号" autocomplete="off" class="layui-input">
</div>
<div class="layui-input-inline">
<input id="password" type="password" name="password" required lay-verify="required" placeholder="密码" autocomplete="off" class="layui-input">
</div>
<div class="layui-input-inline login-btn">
<button type="button" class="layui-btn">登录</button>
</div>
<hr/>
</form>
</div>
<script src="/public/frame/layui/layui.js"></script>
<script type="text/javascript">
var path = '<%=basePath%>';
layui.use(['form', 'layer'], function() {
// 操作对象
var form = layui.form,
$ = layui.jquery,
layer = layui.layer;
// you code ...
function dologin() {
var username = $('input[name="username"]').val();
if(username==null||username==""){
layer.tips('用户名不可为空', '#username');
return ;
}
var password = $('input[name="password"]').val();
if( password==null||password==""){
layer.tips('密码不可为空', '#password');
return ;
}
if (!/[a-zA-Z0-9]{2,}/g.test(username)) {
layer.tips('请输入正确的账号', '#username');
} else if (!/[a-zA-Z0-9_]{4,}/g.test(password)) {
layer.tips('请输入正确的密码', '#password');
} else {
var url = path+"Login/dologin";
var data = {
code: username,
password: password
}
$.post(url, data, function(data) {
if (data.code == 1) {
window.location.href = path+"Index/index";
} else {
layer.msg('用户名或密码输入错误', {
icon: 5
});
}
}, "json");
}
}
//点击登录
$('button[type="button"]').click(function() {
dologin();
});
$('input').keydown(function(e) {
if (e.keyCode == 13) {
dologin();
}
});
});
</script>
</body>
</html>
AI 代码解读
Controller层:
LoginController.java：
@Controller
@RequestMapping(value="Login")
public class LoginController {
@Autowired
private UserService userService;
Api api=new Api();
@RequestMapping(value="/login")
@ResponseBody
public ModelAndView login(){
ModelAndView modelAndView=new ModelAndView();
modelAndView.setViewName("/login.jsp");
return modelAndView;
}
@RequestMapping(value="/dologin")
@ResponseBody
public Map<String,Object> dologin(HttpServletRequest request){
String username = request.getParameter("code");
String password = request.getParameter("password");
if ("".equals(username)){
return api.returnJson(2,"登陆失败,账号密码不能为空");
}
User user=new User();
user.setUsername(username);
user.setPassword(password);
User user1=new User();
user1=userService.findByNameAndPs(user);
if (user1!=null) {
HttpSession session = request.getSession();
session.setAttribute(Const.SESSION_USERNAME, user1.getUsername());
session.setAttribute(Const.SESSION_ID, user1.getUserId());
session.setAttribute(Const.SESSION_USERPASSWORD, user1.getPassword());
return api.returnJson(1,"登陆成功");
}
return api.returnJson(2,"登陆失败");
}
}
AI 代码解读
用户点击登陆按钮，请求到dologin方法。使用账号密码查询数据库数据，看是否有匹配。
以下DAO层:
UserMapper:
package com.example.sl.layer.dao;
import com.example.sl.layer.model.User;
import java.util.List;
public interface UserMapper {
int deleteByPrimaryKey(String userId);
int insert(User record);
User selectByPrimaryKey(String userId);
List<User> selectAll();
int updateByPrimaryKey(User record);
User selectByUnameAndPs(User record);
}
AI 代码解读
Service层:
UserService：
package com.example.sl.layer.service;
import com.example.sl.layer.model.User;
public interface UserService {
public User findByNameAndPs(User user);
}
AI 代码解读
UserServiceImpl:
package com.example.sl.layer.service;
import com.example.sl.layer.dao.LayerMapper;
import com.example.sl.layer.dao.UserMapper;
import com.example.sl.layer.model.User;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import javax.annotation.Resource;
@Service("userService")
@Transactional
public class UserServiceImpl implements UserService{
@Resource
private UserMapper userMapper;
@Override
public User findByNameAndPs(User user) {
return userMapper.selectByUnameAndPs(user);
}
}
AI 代码解读
最后对应到mybatis的UserMapper.xml的sql:
<select id="selectByUnameAndPs" resultMap="BaseResultMap" parameterType="com.example.sl.layer.model.User" >
select user_id, username, password
from user
where username = #{username,jdbcType=VARCHAR}
AND password=#{password,jdbcType=VARCHAR}
</select>
AI 代码解读
然后登陆的时候，我们存入了Session
HttpSession session = request.getSession();
session.setAttribute(Const.SESSION_USERNAME, user1.getUsername());
session.setAttribute(Const.SESSION_ID, user1.getUserId());
session.setAttribute(Const.SESSION_USERPASSWORD, user1.getPassword());
AI 代码解读
这是为了方便我们在JSP中使用EL表达式，如下图:
image.png
对应的代码为:
欢迎,${sessionScope.username}
AI 代码解读
如果登出的话，将Session清空即可。
喜欢就给颗小吧~
