springboot整合mybatis

1，引入依赖

<dependency>
  <groupId>mysql</groupId>
  <artifactId>mysql-connector-java</artifactId>
  <version>5.1.47</version>
  <scope>runtime</scope>
</dependency>

mysql驱动
https://mvnrepository.com/artifact/mysql/mysql-connector-java

<dependency>
    <groupId>org.mybatis.spring.boot</groupId>
    <artifactId>mybatis-spring-boot-starter</artifactId>
    <version>2.2.2</version>
</dependency>

3.0以上版本需要java17

2, 配置数据源

spring:
  datasource:
    url: jdbc:mysql://192.168.56.10:3306/demo?useUnicode=true&useSSL=false&characterEncoding=utf8
    username: root
    password: 123456
    driver-class-name: com.mysql.jdbc.Driver   // mysql5的版本使用这个驱动


mybatis:
  mapper-locations: classpath:mapper/*.xml    // 配置mapper路径

mybatis-spring-boot-starter会自动检测datasource数据源

3，启动类扫描mapper
@MapperScan("com.example.mapper")

4,用法
（1）数据表结构

CREATE TABLE `user` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

(2)user 实体类

import lombok.Data;

@Data
public class User {
    private Integer id;
    private String name;
}

（3）mapper接口

@Mapper
public interface UserMapper {
    public User getUser();
}

（4）service

public interface UserService {
    public User getUser();
}

(5) service实现类

@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserMapper userMapper;
    public User getUser() {
        User user = userMapper.getUser();
        return user;
    }
}

（6）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="top.lihenhao.myspring.mapper.UserMapper">
    <select id="getUser" resultType="top.lihenhao.myspring.model.User">
        select * from user limit 1;
    </select>
</mapper>

(7) controller

@Controller
public class HomeController {

    @Autowired
    private UserService userService;

    @GetMapping("/")
    @ResponseBody
    public User Home() {
        User user  = userService.getUser();
        return user;
    }
}