SpringBoot（四）整合Mybatis-蒲公英云

SpringBoot（四）整合Mybatis

整合Mybatis

一、导入依赖

<!--mybatis启动器依赖-->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>3.0.0</version>
</dependency>
<!--mysql驱动-->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.27</version>
</dependency>

二、编写yml配置文件

spring:
  # 配置数据源
  datasource:
    url: jdbc:mysql://localhost:3306/mybatis_plus?useSSL=false&useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 123456
##配置mybatis
mybatis:
  #  mapper映射文件包扫描
  mapper-locations: classpath:/mapper/*.xml
  #  实体类别名包扫描
  type-aliases-package: com.yka.pojo

三、在启动类上添加注解，表示mapper接口所在位置

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

@SpringBootApplication
//@MapperScan("com.buba.mappers")
public class ApplicationStarter {
  public static void main(String[] args) {
      SpringApplication.run(ApplicationStarter.class,args);
  }

四、定义mapper接口

@Mapper
public interface TestMapper {
    List<String> selectNameAll();
}

五、定义mapper.xml映射文件

在resource下新建mappers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

<?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.buba.mappers.TestMapper">
    <select id="selectNameAll" resultType="string">
        select name from user
    </select>
</mapper>

六、service层

@Service
public class TestServiceImpl implements TestService {
    @Autowired
    private TestMapper testMapper;
    @Override
    public List<String> selectNameAll() {
        return testMapper.selectNameAll();
    }
}

七、controller层

@RestController
@RequestMapping("/test")
public class TestController {
@Autowired
private TestService testService;
@GetMapping("/selectNameAll")
public List<String> selectNameAll() {
    return testService.selectNameAll();
}
}