一   导入依赖

org.mybatis.spring.bootmybatis-spring-boot-starter2.1.3mysqlmysql-connector-java8.0.21org.projectlomboklomboktrue

二    编写配置文件

appliction.yml中添加如下配置

spring:datasource:url: jdbc:mysql://127.0.0.1:3306/mydb?useSSL=false&useUnicode=true&characterEncoding=UTF-8&serverTimezOne=Asia/Shanghaidriver-class-name: com.mysql.cj.jdbc.Driverusername: rootpassword: rootmybatis:mapper-locations: classpath:mybatis/*.xmltype-aliases-package: com.msb.pojo


mapper-locations: classpath:mybatis/*.xml  mapper映射文件包扫描

type-aliases-package:实体类别名包扫描

三   编写功能代码

1.在启动类上添加注解@MapperScan("com.msb.mapper")，表示mapper接口所在位置

@SpringBootApplication@MapperScan("com.msb.mapper")public class MyApplication {public static void main(String[] args) {SpringApplication.run(MyApplication.class,args);}

2 .定义mapper接口

如果不在MyApplication启动类上添加@MapperScan必须在UserMapper接口上添加@Mapper注解。

//@Mapperpublic interface UserMapper {List selectAll();}


3 定义mapper.xml映射文件

在resource下新建mybatis文件夹，mapper.xml文件名没有要求了，不需要和接口名完全对应了，是根据namespace去找接口。但是最好还是和接口名字保持一致

 4 .controller层代码

@Controller@RequestMapping("/user")public class UserController {@Autowiredprivate UserService userService;@RequestMapping("/findAll")@ResponseBodypublic List findAll(){return userService.findAll();}}


 5.service层代码

@Servicepublic class UserServiceImpl implements UserService {@Autowiredprivate UserMapper userMapper;@Overridepublic List findAll() {return userMapper.findAll();}}


6. idea中往往会误报代码错误,如果我们确定代码无问题,可以通过降低idea检查代码的严格程度来消除报错

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