关于springboot:SpringBoot使用Thymeleaf模板实现一个小项目

1. 创立 SpringBoot 我的项目，引入依赖

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>ems-thymeleaf</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>ems-thymeleaf</name>
    <description>ems-thymeleaf</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
            <version>2.5.1</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.26</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.6</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.2.0</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

2. 批改配置文件 application.yml

server:
  port: 8989
  servlet:
    context-path: /ems
spring:
  thymeleaf:
    cache: false
    suffix: .html
    prefix: classpath:/templates/
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource
    url: jdbc:mysql://localhost:3306/mydata?useUnicode=true&characterEncoding=UTF-8
    username: root
    password: 835081
  web:
    #裸露哪些资源能够通过我的项目名拜访
    resources:
      static-locations: classpath:/static/,file:${img.file.dir}
logging:
  level:
    root: info
    com.example.emsthymeleaf: debug
mybatis:
  mapper-locations: classpath:/mapper/*.xml
  type-aliases-package: com.example.emsthymeleaf.entity
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
# 上传文件门路
img:
  file:
    dir: D:\develop\javademo\baizhidemo\ems-thymeleaf\file

3. 创立 Config 文件，将对 html 文件的拜访对应到 Controller

这样做的目标是为了简化拜访 thymeleaf 的 html 文件，不用为每个 html 文件独自创立 controller 申请

package com.example.emsthymeleaf.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration
public class MvcConfig implements WebMvcConfigurer {
    // 不必再为每一个 thymeleaf 模板独自开发一个 controller 申请了
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        //viewController: 申请门路，viewName: 跳转视图
        registry.addViewController("login").setViewName("login");
        registry.addViewController("regist").setViewName("regist");
    }
}

4. 设置随机图形验证码

1. 引入验证码生成工具VerifyCodeUtils
2. 在 controller 中创立生成验证码实例

package com.example.emsthymeleaf.controller;

import com.example.emsthymeleaf.utils.VerifyCodeUtils;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.IOException;

@Controller
@RequestMapping("/user")
public class UserController {@GetMapping("/generateImageCode")
    public void generateImageCode(HttpServletResponse response, HttpSession session) throws IOException {
        // 生成随机数
        String code = VerifyCodeUtils.generateVerifyCode(4);
        // 存入 session
        session.setAttribute("code",code);
        // 依据随机数生成随即图片
        response.setContentType("image/png");
        ServletOutputStream outputStream = response.getOutputStream();
        VerifyCodeUtils.outputImage(220,60,outputStream,code);

    }
}

3. 在 thymeleaf 的 html 文件中设置拜访随机验证码

<td valign="middle" align="right">
   验证码:
   <img id="num" th:src="@{/user/generateImageCode}" />
   <a href="javascript:;" onclick="changeImageCode()"> 换一张 </a>
   <script>
      function changeImageCode(){document.getElementById("num").src='[[@{/user/generateImageCode}]]?' + (new Date()).getTime()}
   </script>
</td>

5. 用户注册

1. 引入 lombok

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.20</version>
</dependency>

2. 创立实体类 User

package com.example.emsthymeleaf.entity;

import lombok.Data;

@Data
public class User {
    private Integer id;
    private String username;
    private String realname;
    private String password;
    private boolean gender;
}

3. controller

@PostMapping("/regist")
public String regist(User user, String code,HttpSession session) throws UnsupportedEncodingException {log.debug("用户信息：" + user);
    log.debug("验证码：" + code);
    try {userSerivce.regist(user,code,session);
    }catch (Exception ex){return "redirect:/regist?err=" + URLEncoder.encode(ex.getMessage(),"UTF-8");
    }

    return "redirect:/login";
}

4. service

package com.example.emsthymeleaf.service;

import com.example.emsthymeleaf.entity.User;

import javax.servlet.http.HttpSession;

public interface UserSerivce {void regist(User user, String code, HttpSession session);
}

5. serviceImpl

package com.example.emsthymeleaf.service;

import com.example.emsthymeleaf.dao.UserDao;
import com.example.emsthymeleaf.entity.User;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.DigestUtils;

import javax.servlet.http.HttpSession;
import java.nio.charset.StandardCharsets;

@Service
@Transactional
public class UserServiceImpl implements UserSerivce {private static final Logger log = LoggerFactory.getLogger(UserServiceImpl.class);
    private UserDao userDao;

    @Autowired
    public UserServiceImpl(UserDao userDao) {this.userDao = userDao;}

    @Override
    public void regist(User user, String code, HttpSession session) {
        // 判断用户输出的验证码和 session 中存储的验证码是否雷同
        log.debug("session code: {}",session.getAttribute("code"));
        if (!code.equalsIgnoreCase(session.getAttribute("code").toString())) {throw new RuntimeException("验证码谬误！");
        }
        // 判断用户名是否已注册过
        if (userDao.getUserByUserName(user.getUsername()) != null) {throw new RuntimeException("用户名已注册过了！");
        }
        // 给明码加密
        user.setPassword(DigestUtils.md5DigestAsHex(user.getPassword().getBytes(StandardCharsets.UTF_8)));
        // 将输出插入到数据表
        userDao.save(user);

    }
}

6. dao

package com.example.emsthymeleaf.dao;

import com.example.emsthymeleaf.entity.User;

public interface UserDao {void save(User user);
    User getUserByUserName(String username);
}

7. xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.emsthymeleaf.dao.UserDao">
    <insert id="save" parameterType="User" useGeneratedKeys="true" keyProperty="id">
        insert into user values(#{id},#{username},#{realname},#{password},#{gender})
    </insert>
    <select id="getUserByUserName" parameterType="String" resultType="User">
        select id,username,realname,password,gender from user where username=#{username}
    </select>
</mapper>

8. 注册页面.html

<div id="content">
    <p id="whereami">
    </p>
    <h1>
        注册 <span style="color: darkred;" th:text="${#request.getParameter('err')}"></span>
    </h1>
    <form th:action="@{/user/regist}" method="post">
        <table cellpadding="0" cellspacing="0" border="0"
               class="form_table">
            <tr>
                <td valign="middle" align="right">
                    用户名:
                </td>
                <td valign="middle" align="left">
                    <input type="text" class="inputgri" name="username" />
                </td>
            </tr>
            <tr>
                <td valign="middle" align="right">
                    实在姓名:
                </td>
                <td valign="middle" align="left">
                    <input type="text" class="inputgri" name="realname" />
                </td>
            </tr>
            <tr>
                <td valign="middle" align="right">
                    明码:
                </td>
                <td valign="middle" align="left">
                    <input type="password" class="inputgri" name="password" />
                </td>
            </tr>
            <tr>
                <td valign="middle" align="right">
                    性别:
                </td>
                <td valign="middle" align="left">
                    男
                    <input type="radio" class="inputgri" name="gender" value="0" checked="checked"/>
                    女
                    <input type="radio" class="inputgri" name="gender" value="1"/>
                </td>
            </tr>

            <tr>
                <td valign="middle" align="right">
                    验证码:
                    <img id="num" th:src="@{/user/generateImageCode}" />
                    <a href="javascript:;" onclick="changeImageCode()"> 换一张 </a>
                    <script>
                        function changeImageCode(){document.getElementById("num").src='[[@{/user/generateImageCode}]]?' + (new Date()).getTime()}
                    </script>
                </td>
                <td valign="middle" align="left">
                    <input type="text" class="inputgri" name="code" />
                </td>
            </tr>
        </table>
        <p>
            <input type="submit" class="button" value="立刻注册 &raquo;" />
            <a th:href="@{/user/generateImageCode}"> 已有账号, 返回登录 </a>
        </p>
    </form>
</div>

6. 用户登录和退出

6.1 用户登录

controller

@RequestMapping("/login")
public String login(String username, String password, HttpSession session) throws UnsupportedEncodingException {
    try {User user = userSerivce.login(username, password);
        session.setAttribute("user", user);
    } catch (Exception e) {e.printStackTrace();
        return "redirect:/login?err=" + URLEncoder.encode(e.getMessage(), "UTF-8");
    }
    return "redirect:/employee/list";

}

service

@Override
public User login(String username, String password) {User user = userDao.getUserByUserName(username);
    if (ObjectUtils.isEmpty(user)) throw new RuntimeException("用户不存在");
    String newPassword = DigestUtils.md5DigestAsHex(password.getBytes(StandardCharsets.UTF_8));
    if (!user.getPassword().equals(newPassword)) throw new RuntimeException(("明码输出谬误"));
    return user;
}

html

<div id="content">
   <p id="whereami">
   </p>
   <h1>
      欢送进入, 请登录!
   </h1>
   <p style="color:red;" th:if="${#request.getParameter('err')}" th:text="' 谬误：' + ${#request.getParameter('err')}"></p>
   <form th:action="@{/user/login}" method="post">
      <table cellpadding="0" cellspacing="0" border="0"
         class="form_table">
         <tr>
            <td valign="middle" align="right">
               用户名:
            </td>
            <td valign="middle" align="left">
               <input type="text" class="inputgri" name="username" />
            </td>
         </tr>
         <tr>
            <td valign="middle" align="right">
               明码:
            </td>
            <td valign="middle" align="left">
               <input type="password" class="inputgri" name="password" />
            </td>
         </tr>
      </table>
      <p>
         <input type="submit" class="button" value="点我登录 &raquo;" />
         &nbsp;&nbsp;
         <a th:href="@{/regist}"> 还没有账号, 立刻注册 </a>
      </p>
   </form>
</div>

6.2 用户退出

controller

// 用户退出
@RequestMapping("/logout")
public String logout(HttpSession session){session.invalidate();
    return "redirect:/login";
}

html

<a th:href="@{/user/logout}"> 平安退出 </a>

7. 员工治理

7.1 增加员工

1. 批改 config 文件，通过浏览器可能拜访到 addEmp.html 页面

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration
public class MvcConfig implements WebMvcConfigurer {
    // 不必再为每一个 thymeleaf 模板独自开发一个 controller 申请了
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        //viewController: 申请门路，viewName: 跳转视图
        registry.addViewController("login").setViewName("login");
        registry.addViewController("regist").setViewName("regist");
        registry.addViewController("addEmp").setViewName("addEmp");
    }
}

2. 增加员工的 controller

package com.example.emsthymeleaf.controller;

import com.example.emsthymeleaf.entity.Employee;
import com.example.emsthymeleaf.service.EmployeeService;
import org.apache.commons.io.FilenameUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

@Controller
@RequestMapping("/employee")
public class EmployeeController {

    @Autowired
    private EmployeeService employeeService;

    private static final Logger log = LoggerFactory.getLogger(EmployeeController.class);

    @Value("${img.file.dir}")
    private String realPath;

    @RequestMapping("/save")
    public String save(Employee employee, MultipartFile img) throws IOException {log.debug("employee: {}",employee);
        log.debug("file name: {}", img.getOriginalFilename());
        // 创立新文件名
        String newImgName = setNewImgName(img);

        // 将头像文件存储到文件夹
        img.transferTo(new File(realPath,newImgName));
        // 存储新的文件名
        employee.setPhoto(newImgName);
        // 存储员工信息
        employeeService.save(employee);
        return "redirect:/employee/list";
    }
    // 生成新的文件名
    private String setNewImgName(MultipartFile img) {
        // 前缀
        String fileNamePrefix = new SimpleDateFormat("yyyyMMddHHmmssSSS").format(new Date());
        // 后缀
        String fileNameSuffix = FilenameUtils.getExtension(img.getOriginalFilename());
        // 新文件名
        String newImgName = fileNamePrefix + "." + fileNameSuffix;
        return newImgName;
    }
}

如何确定文件的上传门路

在 application.yml 中确定文件的上传门路

# 上传文件门路
img:
  file:
    dir: D:\develop\javademo\baizhidemo\ems-thymeleaf\file

在 java 文件中援用它

@Value("${img.file.dir}")
    private String realPath;

serviceImpl

@Override
public void save(Employee employee) {employeeDao.save(employee);
}

dao

void save(Employee employee);

dao.xml

<insert id="save" parameterType="Employee" useGeneratedKeys="true" keyProperty="id">
    insert into employee values (#{id},#{name},#{photo},#{salary},#{birthday})
</insert>

html

<form th:action="@{/employee/save}" method="post" enctype="multipart/form-data">
   <table cellpadding="0" cellspacing="0" border="0"
      class="form_table">
      <tr>
         <td valign="middle" align="right">
            姓名:
         </td>
         <td valign="middle" align="left">
            <input type="text" class="inputgri" name="name" />
         </td>
      </tr>
      <tr>
         <td valign="middle" align="right">
            头像:
         </td>
         <td valign="middle" align="left">
            <input type="file" width=""name="img" />
         </td>
      </tr>
      <tr>
         <td valign="middle" align="right">
            工资:
         </td>
         <td valign="middle" align="left">
            <input type="text" class="inputgri" name="salary" />
         </td>
      </tr>
      <tr>
         <td valign="middle" align="right">
            生日:
         </td>
         <td valign="middle" align="left">
            <input type="text" class="inputgri" name="birthday" />
         </td>
      </tr>
   </table>
   <p>
      <input type="submit" class="button" value="确认增加" />
      <input type="submit" class="button" value="返回列表" />
   </p>
</form>

7.2 员工列表

controller

@RequestMapping("list")
public String list(Model model) {model.addAttribute("list", employeeService.list());
    return "emplist";
}

serviceImpl

@Override
public List<Employee> list() {return employeeDao.list();
}

dao

List<Employee> list();

dao.xml

<select id="list" resultType="Employee">
    select id, name, photo, salary, birthday from `employee`
</select>

html

<div id="content">
   <p id="whereami">
   </p>
   <h1>
      欢送 小陈!
   </h1>
   <table class="table">
      <tr class="table_header">
         <td>
            编号
         </td>
         <td>
            姓名
         </td>
         <td>
            头像
         </td>
         <td>
            工资
         </td>
         <td>
            生日
         </td>
         <td>
            操作
         </td>
      </tr>
      <tr class="row1" th:each="emp:${list}">
         <td>
            <span th:text="${emp.id}"></span>
         </td>
         <td>
            <span th:text="${emp.name}"></span>
         </td>
         <td>
            <img th:src="@{/}+${emp.photo}" width="60">
         </td>
         <td>
            <span th:text="${emp.salary}"></span>
          </td>
          <td>
              <span th:text="${#dates.format(emp.birthday,'yyyy/MM/dd')}"></span>
          </td>
          <td>
              <a href="javascript:;" th:onclick="'deleteEmployee(' + ${emp.id} + ')'"> 删除 </a>
              <a th:href="@{/employee/details(id=${emp.id})}"> 更新 </a>
          </td>
       </tr>
       <script>
           function deleteEmployee(id){if(window.confirm("是否删除这条记录？")){location.href='[[@{/employee/delete?id=}]]' + id
               }
           }
       </script>
   </table>
   <p>
      <input type="button" class="button" value="增加" onclick="addEmp()"/>
      <script type="text/javascript">
         function addEmp() {window.location ='[[@{/addEmp}]]'
         }
      </script>
   </p>
</div>

thymeleaf 须要留神的点

1. 在 <img> 标签中获取以后门路的动态文件：<img th:src="@{/}+${emp.photo}" width="60">，将门路和文件名连接起来

2. 须要批改 application.yml 文件，裸露哪些资源能够通过我的项目名拜访

   resources:
         static-locations: classpath:/static/,file:${img.file.dir}

3. <a>标签链接到带参数的地址：<a href="localhost:8989/ems/employee/details?id=[从 th 参数中获取的 id 值]"> 更新 </a>，在 th 中应该写为：<a th:href="@{/employee/details(id=${emp.id})}"> 更新 </a>
4. 将标签中的链接改为响应 click 事件的 html 语句：

<a href="javascript:;" th:onclick="'deleteEmployee(' + ${emp.id} + ')'"> 删除 </a>
<script>
    function deleteEmployee(id){if(window.confirm("是否删除这条记录？")){location.href='[[@{/employee/delete?id=}]]' + id
        }
    }
</script>

7.3 编辑员工信息

7.3.1 依据 id 获取员工信息

controller

// 依据 id 获取员工信息
@RequestMapping("details")
public String details(Integer id, Model model) {log.debug("id:{}", id);
    Employee employee = employeeService.findById(id);
    model.addAttribute("employee", employee);
    return "updateEmp";
}

service&serviceImpl

Employee findById(Integer id);

@Override
public Employee findById(Integer id) {return employeeDao.findById(id);
}

dao

Employee findById(Integer id);

<select id="findById" parameterType="Integer" resultType="Employee">
    select id, name, photo, salary, birthday from employee where id = #{id}
</select>

html 显示编辑员工信息页面

<form th:action="@{/employee/update}" method="post" enctype="multipart/form-data">
   <table cellpadding="0" cellspacing="0" border="0"
      class="form_table">
      <tr>
         <td valign="middle" align="right">
            编号:
         </td>
         <td valign="middle" align="left">
            <span th:text="${employee.id}"></span>
            <input type="hidden" th:value="${employee.id}" name="id">
         </td>
      </tr>
      <tr>
         <td valign="middle" align="right">
            姓名:
         </td>
         <td valign="middle" align="left">
            <input type="text" class="inputgri" name="name" th:value="${employee.name}"/>
         </td>
      </tr>
      <tr>
         <td valign="middle" align="right">
            以后头像:
         </td>
         <td valign="middle" align="left">
            <img th:src="@{/} + ${employee.photo}" width="60">
            <input type="hidden" name="photo" th:value="${employee.photo}">
         </td>
      </tr>
      <tr>
         <td valign="middle" align="right">
            抉择新头像:
         </td>
         <td valign="middle" align="left">
            <input type="file" name="img" />
         </td>
      </tr>
      <tr>
         <td valign="middle" align="right">
            工资:
         </td>
         <td valign="middle" align="left">
            <input type="text" class="inputgri" name="salary" th:value="${employee.salary}"/>
         </td>
      </tr>
      <tr>
         <td valign="middle" align="right">
            生日:
         </td>
         <td valign="middle" align="left">
            <input type="text" class="inputgri" name="birthday" th:value="${#dates.format(employee.birthday,'yyyy/MM/dd')}"/>
         </td>
      </tr>
   </table>
   <p>
      <input type="submit" class="button" value="更新" />
      <input type="button" class="button" value="返回列表" />
   </p>
</form>

留神两个暗藏类型的 input，因为 <span> 和 <img> 标签的信息无奈通过申请传递，所以这两个标签上面须要设置暗藏类型的 input，用于传递属性值

7.3.2 更新员工信息

controller

// 更新员工信息
@RequestMapping("update")
public String update(Employee employee, MultipartFile img){log.debug("员工信息：{}",employee);
    // 判断是否更新了头像信息
    if (!img.isEmpty()){
        // 更新头像信息
        try {String newImgName = uploadImg(img);
            employee.setPhoto(newImgName);
        } catch (IOException e) {e.printStackTrace();
        }
    }
    employeeService.update(employee);
    return "redirect:/employee/list";
}

/**
 * 存储上传的文件并生成新的文件名
 * @param img
 * @return 返回新的文件名
 * @throws IOException
 */
private String uploadImg(MultipartFile img) throws IOException {
    // 前缀
    String fileNamePrefix = new SimpleDateFormat("yyyyMMddHHmmssSSS").format(new Date());
    // 后缀
    String fileNameSuffix = FilenameUtils.getExtension(img.getOriginalFilename());
    // 新文件名
    String newImgName = fileNamePrefix + "." + fileNameSuffix;
    // 将头像文件存储到文件夹
    img.transferTo(new File(realPath, newImgName));
    return newImgName;
}

service&serviceImpl

void update(Employee employee);

@Override
public void update(Employee employee) {employeeDao.update(employee);
}

dao

void update(Employee employee);

<update id="update" parameterType="Employee">
    update employee set name=#{name},photo=#{photo},salary=#{salary},birthday=#{birthday} where id = #{id}
</update>

7.3.3 删除员工信息

controller

// 删除员工信息
@RequestMapping("/delete")
public String delete(Integer id){log.debug("id={}",id);
    employeeService.delete(id);
    return "redirect:/employee/list";
}

service&serviceImpl

void delete(Integer id);

@Override
public void delete(Integer id) {employeeDao.delete(id);
}

dao

void delete(Integer id);

<delete id="delete" parameterType="Integer">
    delete from employee where id=#{id}
</delete>

8. 拦截器，拦挡未登录用户

定义拦截器

package com.example.emsthymeleaf.interceptors;

import org.springframework.web.servlet.HandlerInterceptor;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class MyInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {HttpSession session = request.getSession();
        if (session.getAttribute("user") == null){response.sendRedirect(request.getContextPath() + "/login");
            return false;
        }
        return true;
    }
}

配置拦截器

package com.example.emsthymeleaf.config;

import com.example.emsthymeleaf.interceptors.MyInterceptor;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
@Configuration
public class MvcConfig implements WebMvcConfigurer {
    // 配置拦截器
    @Override
    public void addInterceptors(InterceptorRegistry registry) {registry.addInterceptor(new MyInterceptor())
                .addPathPatterns("/**")
                .excludePathPatterns("/user/**","/login","regist");
    }

    // 不必再为每一个 thymeleaf 模板独自开发一个 controller 申请了
    @Override
    public void addViewControllers(ViewControllerRegistry registry) {
        //viewController: 申请门路，viewName: 跳转视图
        registry.addViewController("login").setViewName("login");
        registry.addViewController("regist").setViewName("regist");
        registry.addViewController("addEmp").setViewName("addEmp");
    }
}

9. 其余一些细节

• 在 html 中获取 session 中的用户名

  欢送 <span th:text="${#session.getAttribute('user').realname}"></span>!