1.使用通用mapper可以更快速的进行数据库的增删查改操作,加入springboot的管理,常规的SQL都可以复用
2.整合
　a)引入依赖

    tk.mybatismapper-spring-boot-starter2.0.2
org.mybatis.spring.bootmybatis-spring-boot-starter1.3.2
mysqlmysql-connector-java5.1.47
org.springframework.bootspring-boot-starter-weborg.springframeworkspring-coreorg.springframeworkspring-beans

．　1)注意:这里由于引入的依赖包含好多spring有关的依赖,导致spring的版本可能不兼容.因此还需要增加以下标签,实现对所有有关spring的依赖版本的管理,使版本一一致或兼容

org.springframework.bootspring-boot-starter-parent2.0.5.RELEASE

．b)配置文件

server:port: 8080
#jdbc
spring:datasource:driver-class-name: com.mysql.jdbc.Driverurl: jdbc:mysql://localhost:3306/project1?useUnicode=true&characterEncoding=utf8username: rootpassword: 123456
#mybatis
mybatis:type-aliases-package: com.brant.entity
#通用mapper配置
mapper:mappers: com.brant.basedao.IBaseDaoidentity: MYSQL

．c)配置启动类,这里需要注意MapperScan需要引入tk的包

@SpringBootApplication
@MapperScan({"com.brant.dao"})
public class MyApplication {public MyApplication() {}public static void main(String[] args) {SpringApplication.run(MyApplication.class, args);}
}

．d)建立src目录

e)生成数据库和表cities
1)sql

create table cities(id int primary key auto_increment,cityid varchar(20) not null,city varchar(20) not null,provinceid varchar(20) not null
);INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '110100', '市辖区', '110000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '110200', '县', '110000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '120100', '市辖区', '120000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '120200', '县', '120000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '130100', '石家庄市', '130000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '130200', '唐山市', '130000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '130300', '秦皇岛市', '130000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '130400', '邯郸市', '130000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '130500', '邢台市', '130000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '130600', '保定市', '130000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '130700', '张家口市', '130000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '130800', '承德市', '130000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '130900', '沧州市', '130000');
INSERT INTO `cities`(`id`, `cityid`, `city`, `provinceid`) VALUES (null, '131000', '廊坊市', '130000');

．ｅ)建立实体类映射,并实现序列化

@Repository
@Table(name = "cities")
public class Citiy implements Serializable {@Id@GeneratedValue(strategy = GenerationType.IDENTITY)@Column(name = "id")private Integer id;@Column(name = "cityid")private String cityId;@Column(name = "city")private String city;@Column(name = "provinceid")private String provinceId;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getCityId() {return cityId;}public void setCityId(String cityId) {this.cityId = cityId;}public String getCity() {return city;}public void setCity(String city) {this.city = city;}public String getProvinceId() {return provinceId;}public void setProvinceId(String provinceId) {this.provinceId = provinceId;}@Overridepublic String toString() {return "Cities{" +"id=" + id +", cityId='" + cityId + '\'' +", city='" + city + '\'' +", provinceId='" + provinceId + '\'' +'}';}
}

．ｆ)依次编写业务控制层,服务业务层和mapper层

@Controller
@RequestMapping("/city")
public class CityController {@Autowiredprivate ICityService iCityService;@Autowiredprivate Cities cities;@RequestMapping(method = RequestMethod.GET,path = "/selectAll")@ResponseBodypublic List selectAll(){return iCityService.selectAll();}@RequestMapping(method = RequestMethod.GET,path = "/selectOne/{id}")@ResponseBodypublic Cities selectOne(@PathVariable int id){cities.setId(id);return iCityService.selectOne(cities);}}

public interface ICityService {List selectAll();Cities selectOne(Cities cities);
}

@Service
public class CityServiceImpl implements ICityService {@Autowiredprivate ICityDao cityDao;@Overridepublic List selectAll() {return cityDao.selectAll();}@Overridepublic Cities selectOne(Cities cities) {return cityDao.selectOne(cities);}
}

/*** @author brant* @date 2023/3/5 01:38* 这里如果要使用mapper自己封装的方法,不要重写方法.否则会报错 Invalid bound statement (not found)*/
@Component
public interface ICityDao extends IBaseDao{}

public interface IBaseDao extends Mapper,MySqlMapper {
}

．　1)注意:由于这里使用了mapper的自己的方法,因此在写dao层时不需要重写方法了,否则spring会找不到mapper的方法.这时的dao也要添加@Component注解,交给spring管理
　ｇ)使用postman完成接口测试


．ｈ)总结,在使用通用mapper时需要注意以下几点
　　1)检查application.yml文件配置是否正确
　　2)检查dao方法(这里排查了1h,很难排查)
　　3)MapperScan导包tk
　　4)pom文件要加入springboot版本管理