流程：
Springboot开发过程
还有一个是mybatis的依赖
测试接口
@RestController
public class Hello {
@RequestMapping("/hello")
public String hello(){
return "helloworld";
}
}***.yml文件配置
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/student?useUnicode=true&useSSL=false&characterEncoding=utf8&serverTimezone=Asia/Shanghai
username: root
password: 123456
mybatis:
mapper-locations: classpath:mapper/*.xml数据库字段：
pojo
@Data
public class User {
private int id ;
private String name;
private int age;
private String email;
*****剩下的就是get和set方法自行完成
mapper
@Mapper
public interface UserMapper {
List<User> findAll();
}如果是springboot,在启动类中使用@MapperScan(“mapper接口所在包全名”)即可，不用一个一个的在Mapper接口中加@Mapper注解。@Mapper注解是识别他为mybatis的mapper接口，会自动的把 加@Mapper 注解的接口生成动态代理类。
让springboot认识你的mapper层，也可以在启动类上面加MapperScan(“mapper层所在包的全名”)
mapper.xml
<?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.liuyang.mapper.UserMapper">
<select id="findAll" resultType="com.liuyang.entity.User">
SELECT * FROM user
</select>
</mapper>controller
@RestController
public class UserController {
@Autowired
//把userService实例化
private UserService userService;
@RequestMapping("/user")
public List<User> getUser(){
return userService.findAll();
}
}注意一定要把userService 注入到容器中
数据成功拿到
