第一步 配置pom.xml

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jdbc</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.2</version>
</dependency>
<dependency>
    <groupId>icu.mhb</groupId>
    <artifactId>mybatis-plus-join</artifactId>
    <version>1.1.2</version>
</dependency>

<!--日志文件功能-->
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.7.25</version>
</dependency>
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>1.7.21</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-devtools</artifactId>
    <scope>runtime</scope>
    <optional>true</optional>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <optional>true</optional>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
    <exclusions>
        <exclusion>
            <groupId>org.junit.vintage</groupId>
            <artifactId>junit-vintage-engine</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<!-- 分页插件-->
<!--  分页插件  -->
<!-- http://repo1.maven.org/maven2/com/github/pagehelper/pagehelper/-->
<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper</artifactId>
    <version>5.1.2</version>
</dependency>
<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper-spring-boot-autoconfigure</artifactId>
    <version>1.2.5</version>
</dependency>

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper-spring-boot-starter</artifactId>
    <version>1.2.5</version>
    <exclusions>
        <exclusion>
            <artifactId>mybatis</artifactId>
            <groupId>org.mybatis</groupId>
        </exclusion>
        <exclusion>
            <artifactId>mybatis-spring</artifactId>
            <groupId>org.mybatis</groupId>
        </exclusion>
    </exclusions>
</dependency>

第二步 配置application.yml

spring:
  datasource:
    driverClassName: com.mysql.cj.jdbc.Driver
    url:  jdbc:mysql://localhost:3306/mybatis_use?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=UTC
    username: root
    password: root
  servlet:
    multipart:
      #上传文件总的最大值
      max-request-size: 10MB
      #上传文件的最大值
      max-file-size: 100MB
mybatis-plus:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.demo.mybatis_use.pojo
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
pagehelper:
  helper-dialect: mysql
  #设置为true时，pageNum<=0时会查询第一页，pageNum>pages时会查询最后一页
  reasonable: true
  support-methods-arguments: true
  params: count=countSql
server:
  # 服务端口
  port: 9080

补充信息

补充一 拦截器的使用

第一步 拦截器的创立

@Component
public class CrossDomainRequestInterceptor implements HandlerInterceptor {

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        String origin = request.getHeader("Origin");
        response.setHeader("Access-Control-Allow-Origin", origin);
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
        response.setHeader("Access-Control-Max-Age", "3600");
        // response.setHeader("Access-Control-Allow-Headers", "x-requested-with,Authorization");
        response.setHeader("Access-Control-Allow-Headers", "Content-Type,Access-Token"); // 解决vue-axios请求报错问题
        response.setHeader("Access-Control-Allow-Credentials", "true");

        return true;
    }
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
    }
}

第二步 拦截器的注册

@Resource
private CrossDomainRequestInterceptor crossDomainRequestInterceptor;

@Override
public void addInterceptors(InterceptorRegistry registry) {
    // TODO Auto-generated method stub
    registry.addInterceptor(crossDomainRequestInterceptor)
            // 拦截路劲
            .addPathPatterns("/**");

}