Spring Boot 利用注解方式整合 MyBatis

<!--     springboot mybatis 整合包   -->
<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.1.3</version>
</dependency>
<!--    mysql 驱动    -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <scope>runtime</scope>
</dependency>

CREATE TABLE `user` (
  `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '主键',
  `name` varchar(50) DEFAULT NULL COMMENT '姓名',
  `age` int(11) DEFAULT NULL COMMENT '年龄',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;

INSERT INTO  user values (1,"村雨遥",25);
INSERT INTO  user values (2,"张三",26);
INSERT INTO  user values (3,"李四",27);

# 数据库配置
spring.datasource.username=root
spring.datasource.password=0908
spring.datasource.url=jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <optional>true</optional>
</dependency>

package com.cunyu.pojo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
/**
 * @author : cunyu
 * @version : 1.0
 * @className : User
 * @date : 2020/7/26 20:44
 * @description : User 实体类
 */
@Data
@NoArgsConstructor
@AllArgsConstructor
public class User {
    private Long id;
    private String name;
    private Integer age;
}

package com.cunyu.dao;
import com.cunyu.pojo.User;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Select;

/**
 * @InterfaceName : UserDao
 * @Author : cunyu
 * @Date : 2020/7/26 20:47
 * @Version : 1.0
 * @Description : User 类对应接口
 **/
@Mapper
public interface UserDao {
    /**
     * @param id 用户 id
     * @return 对应 id 的用户
     * @description 根据用户 id 查询用户
     * @date 2020/7/26 20:48
     * @author cunyu1943
     * @version 1.0
     */

    @Select("SELECT id,name,age FROM user where id = #{id}")
    User getUserById(Long id);
}

package com.cunyu.service;
import com.cunyu.pojo.User;
/**
 * @author : cunyu
 * @version : 1.0
 * @className : UserService
 * @date : 2020/7/26 20:57
 * @description : User service 接口
 */
public interface UserService {
    /**
     * @param id 用户 iD
     * @return 对应 id 的用户
     * @description 根据 id 查找用户
     * @date 2020/7/26 20:58
     * @author cunyu1943
     * @version 1.0
     */
    User getUserById(Long id);
}

package com.cunyu.service.impl;
import com.cunyu.dao.UserDao;
import com.cunyu.pojo.User;
import com.cunyu.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
/**
 * @description : service 接口实现类
 */
@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserDao userDao;
    @Override
    public User getUserById(Long id) {
        return userDao.getUserById(id);
    }
}

package com.cunyu.controller;
import com.cunyu.pojo.User;
import com.cunyu.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class UserController {
    /**
     * 自动注入
     */
    @Autowired
    private UserService userService;

    @GetMapping("/user")
    public User getUserById() {
        User user = userService.getUserById(1L);
        return user;
    }
}

package com.cunyu;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@MapperScan(basePackages = "com.cunyu.dao")
@SpringBootApplication
public class MybatisXmlApplication {
    public static void main(String[] args) {
        SpringApplication.run(MybatisXmlApplication.class, args);
    }
}