开发环境搭建

创建工程

application.yml:

server:
  port: 80
spring:
  application:
    name: reggie_take
  datasource:
      type: com.alibaba.druid.pool.DruidDataSource
      driver-class-name: com.mysql.cj.jdbc.Driver
      url: jdbc:mysql://localhost:3306/reggie
      username: root
      password: 123


mybatis-plus:
  configuration:
    #是否
    map-underscore-to-camel-case: true
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
  global-config:
    db-config:
      id-type: ASSIGN_ID

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>3.0.0</version>
      <relativePath/> <!-- lookup parent from repository -->
   </parent>
   <groupId>com.itheima</groupId>
   <artifactId>reggie_take</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <name>reggie_take</name>
   <description>reggie_take</description>
   <properties>
      <java.version>18</java.version>
   </properties>
   <dependencies>

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

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

      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-web</artifactId>
         <scope>compile</scope>
      </dependency>

      <dependency>
         <groupId>com.baomidou</groupId>
         <artifactId>mybatis-plus-boot-starter</artifactId>
         <version>3.4.2</version>
      </dependency>

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

      <dependency>
         <groupId>com.alibaba</groupId>
         <artifactId>fastjson</artifactId>
         <version>1.2.76</version>
      </dependency>

      <dependency>
         <groupId>commons-lang</groupId>
         <artifactId>commons-lang</artifactId>
         <version>2.6</version>
      </dependency>

      <dependency>
         <groupId>mysql</groupId>
         <artifactId>mysql-connector-java</artifactId>
         <scope>runtime</scope>
      </dependency>

      <dependency>
         <groupId>com.alibaba</groupId>
         <artifactId>druid-spring-boot-starter</artifactId>
         <version>1.2.8</version>
      </dependency>
   </dependencies>

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

</project>

我们的静态资源没有放在static包里，所以要做相应的映射

后台登录功能开发(springboot 不要用3.0.0)

controller:

@Slf4j
@RestController
@RequestMapping("/employee")
public class EmployeeController {
    @Resource
    private EmployeeService employeeService;

    /**
     * 员工登录
     * @param
     * @param employee
     * @return
     */
    @PostMapping("/login")
    public R login(HttpServletRequest request, @RequestBody Employee employee){
        //将页面提交的密码加密
        String password =employee.getPassword();
        password= DigestUtils.md5DigestAsHex(password.getBytes());
        //2.根据页面提交的用户名查询数据库
        LambdaQueryWrapper<Employee> queryWrapper =new LambdaQueryWrapper<>();
        queryWrapper.eq(Employee::getUsername,employee.getUsername());
        Employee emp =employeeService.getOne(queryWrapper);
        //如果没查询到就返回登录失败
        if(emp == null) {
            return new R(0,"登录失败",null);

        }
        //查到了就进行密码比对
        if (!emp.getPassword().equals(password)){
            return new R(0,"登录失败");
        }
        //比对成功  查看员工状态是否为禁用
        if(emp.getStatus()==0){
            return new R(0,"账号已禁用");
        }
        //登录成功，将员工id存入Session 并返回登录成功结果
        request.getSession().setAttribute("employee",emp.getId());
        return new R(1,"登录成功",emp);
    }


    @PostMapping("/logout")
    public R logout(HttpServletRequest request){
        request.getSession().removeAttribute("employee");
        return new R(1,"退出成功");
    }
}

问题：当前我们虽然完成了功能，但是用户不登录，还是能访问系统首页，是不合理的

所以用户没有登录，必须要跳转到登录页面

答案就是使用过滤器或者拦截器，在过滤器或者拦截器中判断用户是否已经完成登录，如果没有登录则跳转到登录页面。

@WebFilter(filterName = "loginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    public static final AntPathMatcher PATH_MATCHER =new AntPathMatcher();
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request =(HttpServletRequest) servletRequest;
        HttpServletResponse response =(HttpServletResponse) servletResponse;
      log.info("拦截到请求：{}",request.getRequestURI());
    //1.获取本次请求的URI
        String requestURI =request.getRequestURI();
        //定义不需要处理的请求路径
        String[] urls= new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "/front/**"
        };
        //判断本次请求是否需要处理
        boolean check =check(urls,requestURI);

        //如果不需要处理则直接放行
        if(check){
            log.info("本次请求{}不需要处理",requestURI);
            filterChain.doFilter(request,response);
            return;
        }
        //判断登录状态，如果已登录，则直接放行
        if(request.getSession().getAttribute("employee")!=null){
            log.info("用户已登录，id为：{}",request.getSession().getAttribute("employee"));
            filterChain.doFilter(request,response);
            return;
        }
        log.info("未登录");
        //如果未登录则返回未登录结果，通过输出流的方式像客户端页面响应数据
        response.getWriter().write(JSON.toJSONString((new R(0,"NOTLOGIN"))));
        return;

    }


    /**
     * 路径匹配，检查请求是否需要放行
     * @param urls
     * @return
     */

    public boolean check(String[] urls,String requestURI){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match){
                return true;
            }

        }
        return false;
    }
}