使用SpringBoot+MyBatis+MySQL完成面试题（部分）

1.先搭建项目，选择Web、MyBatis、MySQL等依赖。
整体项目格式：

配置文件：

spring.datasource.url=jdbc:mysql://localhost:3306/Interview?useUnicode=true&characterEncoding=utf8
spring.datasource.username=root
spring.datasource.password=123
#spring.datasource.driver-class-name=com.mysql.jdbc.Driver
mybatis.mapper-locations=classpath:mapper/*Mapper.xml
server.port=8081

注意，这里如果开启了

spring.datasource.driver-class-name=com.mysql.jdbc.Driver会报错：

Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.

2.创建好数据库和表。
3.在pom.xml文件里引入lombok依赖。

<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.16.10</version>
</dependency>

4.创建实体类ShopPojo：

package com.example.demo.Pojo;

import lombok.Data;
import lombok.ToString;

@Data
@ToString
public class ShopPojo {
private String id;
private String shopName;
}

5.ShopMapper.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.example.demo.Mapper.ShopMapper">
<resultMap id="shop" type="com.example.demo.Pojo.ShopPojo">
<id property="id" column="id"></id>
<result property="shopName" column="shopName"></result>
</resultMap>

<select id="findAllShops" resultMap="shop">
SELECT * FROM shop
</select>

</mapper>

ShopMapper接口：

package com.example.demo.Mapper;

import com.example.demo.Pojo.ShopPojo;
import org.apache.ibatis.annotations.Mapper;
import java.util.List;

@Mapper
public interface ShopMapper {
List<ShopPojo> findAllShops();
}

(@Mapper注意不要漏了)
6.ShopService 和 ShopServiceImpl:

package com.example.demo.Service;

import com.example.demo.Pojo.ShopPojo;
import java.util.List;

public interface ShopService {
List<ShopPojo> findAllShops();
}

package com.example.demo.Service.ServiceImpl;

import com.example.demo.Mapper.ShopMapper;
import com.example.demo.Pojo.ShopPojo;
import com.example.demo.Service.ShopService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;

@Service
public class ShopServiceImpl implements ShopService {

@Autowired
private ShopMapper shopMapper;

@Override
public List<ShopPojo> findAllShops() {
List<ShopPojo> shops = shopMapper.findAllShops();
for (ShopPojo shop : shops) {
System.out.println(shop);
}
return shops;
}
}

7.ShopController:

package com.example.demo.Controller;

import com.example.demo.Pojo.ShopPojo;
import com.example.demo.Service.ShopService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class ShopController {

@Autowired
private ShopService shopService;

@RequestMapping("/findAllShops")
public List<ShopPojo> findAllShops(){
return shopService.findAllShops(); }
}

@RestController:是@RequestBody和@Controller的合体。

8.测试结果：

遇到的问题：
数据库时区问题，可以这样解决：