<!-- https://mvnrepository.com/artifact/com.h2database/h2 -->
<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <version>1.4.199</version>
    <scope>test</scope>
</dependency>

<!--springmvc-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--h2數(shù)據(jù)庫(kù)-->
<dependency>
    <groupId>com.h2database</groupId>
    <artifactId>h2</artifactId>
    <!--version:1.4.200-->
    <scope>compile</scope>
</dependency>
<!--mp-->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.2</version>
</dependency>
<!--mysql驅(qū)動(dòng)-->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.47</version>
</dependency>
<!--test-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
</dependency>
<!-- lombok -->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
</dependency>

server:
  port: 8888 # 端口號(hào)
spring:
  datasource:
    url: jdbc:h2:~/mydb  # 數(shù)據(jù)庫(kù)
    driver-class-name: org.h2.Driver
    username: root  
    password: test
  h2:
    console:
      path: /h2-console  #h2嵌入式數(shù)據(jù)庫(kù)控制臺(tái)，可以通過瀏覽器訪問
      enabled: true
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl # 開啟sql日志
    map-underscore-to-case: true # 開啟駝峰映射(mp默認(rèn)開啟)

package com.baidou.entity;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;
/**
 * 實(shí)體類
 *
 * @author 白豆五
 * @version 2023/04/4
 * @since JDK8
 */
@Data
@TableName(value = "tb_user")
public class User {
    private Integer id;
    private String username;
    private String pwd;
    private Integer salary;//以分為單位,避免浮點(diǎn)運(yùn)算精度丟失問題
    // 封裝數(shù)據(jù)
    public void setSalary(Integer salary) {
        this.salary = salary * 100;
    }
}

package com.baidou.mapper;
import com.baidou.entity.User;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;
//mapper接口
@Mapper
public interface UserMapper extends BaseMapper<User> {
}

package com.baidou.service;
import com.baidou.entity.User;
import com.baomidou.mybatisplus.extension.service.IService;
// service接口
public interface UserService extends IService<User> {
}

package com.baidou.service.impl;
import com.baidou.entity.User;
import com.baidou.mapper.UserMapper;
import com.baidou.service.UserService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.stereotype.Service;
/**
 * service接口實(shí)現(xiàn)類
 *
 * @author 白豆五
 * @version 2023/04/4
 * @since JDK8
 */
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {
}

DROP TABLE IF EXISTS tb_user;
CREATE TABLE tb_user(
    id INT(11) PRIMARY KEY  AUTO_INCREMENT COMMENT 'id',
    username VARCHAR(30) NOT NULL UNIQUE COMMENT '用戶名',
    pwd VARCHAR(10) NOT NULL COMMENT '密碼',
    salary  INT  NULL DEFAULT 0 COMMENT '薪資'
);

package com.baidou.config;
import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.core.io.Resource;
import org.springframework.stereotype.Component;
/**
 * 定義一個(gè)注冊(cè)器策略類,方便后續(xù)加載資源文件
 *
 * ApplicationContextAware是Spring框架提供的接口,也叫做spring上下文的增強(qiáng)器,在項(xiàng)目啟動(dòng)時(shí)執(zhí)行,會(huì)被spring處理
 * 當(dāng)一個(gè)bean實(shí)現(xiàn)了該接口,通過setApplicationContext方法可以直接獲取spring容器中的所有bean
 */
@Component
public class ApplicationContextRegister implements ApplicationContextAware {
    private ApplicationContext applicationContext = null;
    /**
     * Spring容器啟動(dòng)時(shí)，會(huì)回調(diào)setApplicationContext方法，并傳入ApplicationContext對(duì)象，之后就可對(duì)該對(duì)象進(jìn)行操作。（例如獲取spring容器中的所有bean）
     *
     * @throws BeansException
     */
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        this.applicationContext = applicationContext;
    }
    /**
     * 提供一個(gè)方法,用于加載sql腳本文件
     *
     * @param url sql文件位置
     * @return
     */
    public Resource getResource(String url) {
        return this.applicationContext.getResource(url);
    }
}

package com.baidou.config;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.core.io.Resource;
import org.springframework.jdbc.datasource.init.ScriptUtils;
import org.springframework.stereotype.Service;
import javax.annotation.PostConstruct;
import javax.sql.DataSource;
import java.io.File;
/**
 * 初始化h2數(shù)據(jù)庫(kù)
 */
@Slf4j
@Service
@AutoConfigureAfter(DataSource.class) //DataSource創(chuàng)建完后才初始化此類
public class H2DataSourceConfig {
    //初始化sql
    private static final String schema="classpath:db/schema-h2.sql";
    @Autowired
    DataSource dataSource;
    @Autowired
    ApplicationContextRegister applicationContextRegister; //自定義注冊(cè)器
    // JDK提供的注解,在方法上加該注解會(huì)在項(xiàng)目啟動(dòng)的時(shí)候執(zhí)行該方法,也可以理解為在spring容器初始化的時(shí)候執(zhí)行該方法
    @PostConstruct
    public  void init() throws Exception {
        //初始化本地?cái)?shù)據(jù)庫(kù)
        String userHome= System.getProperty("user.home");//獲取系統(tǒng)用戶目錄
        // 創(chuàng)建一個(gè)標(biāo)識(shí)文件,只有在第一次初始化數(shù)據(jù)庫(kù)時(shí)會(huì)創(chuàng)建,如果系統(tǒng)用戶目錄下有這個(gè)文件,就不會(huì)重新執(zhí)行sql腳本
        File f = new File(userHome+ File.separator+"my.lock");
        if(!f.exists()){
            log.info("--------------初始化h2數(shù)據(jù)----------------------");
            f.createNewFile();
            // 加載資源文件
            Resource resource= (Resource) applicationContextRegister.getResource(schema);
            // 手動(dòng)執(zhí)行SQL語句
            ScriptUtils.executeSqlScript(dataSource.getConnection(),resource);
        }
    }
}

package com.baidou.test;
import com.baidou.entity.User;
import com.baidou.service.UserService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import java.util.List;
/**
 * 使用MP操作H2數(shù)據(jù)庫(kù)
 *
 * @author 白豆五
 * @version 2023/04/4
 * @since JDK8
 */
@SpringBootTest
public class H2Test {
    @Autowired
    private UserService userService;
    @Test
    public void test1() {
        User user = new User();
        user.setId(1);
        user.setUsername("張三");
        user.setPwd("123456e");
        user.setSalary(10000); //10k
        boolean flag = userService.save(user);
        System.out.println(flag ? "插入成功" : "插入失敗");
    }
    @Test
    public void test2() {
        List<User> list = userService.list();
        System.out.println(list);
    }
}