<!--配置通用Mapper start-->
        <dependency>
            <groupId>tk.mybatis</groupId>
            <artifactId>mapper-spring-boot-starter</artifactId>
            <version>2.1.5</version>
        </dependency>
        <!--通用Mapper end-->

@Repository
public interface UserDao extends Mapper<User> {
 
}

@Service("userService")
public calss UserServiceImpl implements UserService{
    @Autowired
    private UserDao userDao;

    @Override
    public List<User> list(){
    return userDao.selectALL();
    }

}
    

import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;

public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer id;
    private  String name;
    private  Integer age;

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getAge() {
        return age;
    }

    public void setAge(Integer age) {
        this.age = age;
    }

}

import tk.mybatis.spring.annotation.MapperScan;//把MapperScan的导入路径换成tk.mybatis.spring.annotation.MapperScan
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.transaction.annotation.EnableTransactionManagement;

@SpringBootApplication
@EnableTransactionManagement //开启书屋管理注解模式 最新的版本可以省略
@MapperScan("com.xz.springboot.mapper") //扫描该包下所有的接口并为该接口生成实现类
public class Springboot01Application {

    public static void main(String[] args) {
        SpringApplication.run(Springboot01Application.class, args);
    }

}