1、

2、具体分析
mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <settings>
        <!--开启驼峰命名规则-->
        <setting name="mapUnderscoreToCamelCase" value="true" />
    </settings>
</configuration>

application.yml

spring:
  datasource:
    username: root
    password: root
    url: jdbc:mysql://127.0.0.1:3306/booksystem
    driver-class-name: com.mysql.jdbc.Driver
mybatis:
  config-location: classpath:mybatis/mybatis-config.xml
  mapper-locations: classpath:mybatis/mapper/*.xml

启动类上@MapperScan注解

这个value值是要扫描的mapper的包名
@MapperScan(value = "com.atgui.dao")

Service的实现类上的@Service注解，其中注入的是Mapper

@Service
public class BookServiceImpl implements BookService {
@Autowired
    BookMapper bookMapper;
    @Override
    public List<Book> findAllBook() {
        return bookMapper.findAllBook();
    }

}

控制层@Controller注解，其中注入的是service层的实现类

@Controller
public class BookController {
    @Autowired
    BookServiceImpl bookService;
}

添加依赖

需要什么添加什么

通常一个web项目，需要添加的依赖有
模板引擎的依赖

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

<thymeleaf.version>3.0.2.RELEASE</thymeleaf.version>
        <thymeleaf-layout-dialect.version>2.1.1</thymeleaf-layout-dialect.version>

分页插件的依赖

<dependency>
            <groupId>com.github.pagehelper</groupId>
            <artifactId>pagehelper-spring-boot-starter</artifactId>
            <version>1.2.2</version>
        </dependency>

数据源的依赖，后期会使用阿里云的druid

<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.8</version>
</dependency>