H2 不香么? 为什么使用MariaDB4J ?

谈到在测试中使用内存数据库，估计首先想到的就是H2了。使用时也非常方便，只要在下述SpringBoot的配置文件里修改一下datasource即可。application.propertiesspring.datasource.url=jdbc:h2:mem:testdb

spring.datasource.driverClassName=org.h2.Driver

spring.datasource.username=sa

spring.datasource.password=

spring.jpa.database-platform=org.hibernate.dialect.H2Dialect

然后一个名字为testdb的数据库就就绪了。如果要导入数据库表和基础数据的话，也只要在src/test/resouces下面提供如下两个文件

schema.sql – 创建schema和表

data.sql – 导入基础数据

看上去是不是很方便呢？

不过随着在项目中使用的深入，就发现了一些问题语法上兼容性(如注释)以及产品功能上的问题(如多层临时表)，具体可以关注笔者之前整理的一个list。如果选择继续使用H2,就需要团队为H2去维护另外一套H2专用的schema。因此，使用MySQL的团队需要额外寻找一个H2的替代品，一个更兼容MySQL的内存数据库。

经过一番搜索，MariaDB4J 终于走进了团队的视野。https://github.com/vorburger/MariaDB4j这个开源项目的目标就是让用户use MariaDB (MySQL(R)) from Java without ANY installation / external dependencies

在SpringBoot项目中使用

来看看如何使用它。以下是一个测试专用的App基类package com.testlink4j;

import org.mybatis.spring.annotation.MapperScan;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.context.annotation.Configuration;

import ch.vorburger.mariadb4j.springframework.MariaDB4jSpringService;

@Configuration

@SpringBootApplication

// mapper 接口类扫描包配置

@MapperScan("com.testlink4j.dao")

public class TestApplication{//extends Application {

public static void main(String[] args){

SpringApplication.run(TestApplication.class,args);

}

private final MariaDB4jSpringService mariaDB4JSpringService;

@Autowired

public TestApplication (MariaDB4jSpringService mariaDB4JSpringService){

this.mariaDB4JSpringService= mariaDB4JSpringService;

}

}

通过给Spring应用提供一个测试用的TestApplication，并提供一个带有MariaDB4jSpringService 作为入参，就可以实现数据库的启动了。. ____ _ __ _ _

/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \

( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \

\\/ ___)| |_)| | | | | || (_| | ) ) ) )

' |____| .__|_| |_|_| |_\__, | / / / /

=========|_|==============|___/=/_/_/_/

:: Spring Boot :: (v2.2.5.RELEASE)

INFO 7264 --- [ main] c.t.s.impl.TestProjectServiceImplTest : No active profile set, falling back to default profiles: default

.s.d.r.c.RepositoryConfigurationDelegate : Finished Spring Data repository scanning in 35ms. Found 0 JPA repository interfaces.

INFO 7264 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat initialized with port(s): 0 (http)

INFO 7264 --- [ main] o.apache.catalina.core.StandardService : Starting service [Tomcat]

INFO 7264 --- [ main] org.apache.catalina.core.StandardEngine : Starting Servlet engine: [Apache Tomcat/9.0.31]

INFO 7264 --- [ main] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring embedded WebApplicationContext

INFO 7264 --- [ main] o.s.web.context.ContextLoader : Root WebApplicationContext: initialization completed in 7118 ms

INFO 7264 --- [ main] ch.vorburger.mariadb4j.DB : Installation complete.

INFO 7264 --- [ main] ch.vorburger.mariadb4j.DB : Starting up the database...

INFO 7264 --- [ main] ch.vorburger.mariadb4j.DB : Database startup complete.

INFO 7264 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...

INFO 7264 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed.

INFO 7264 --- [ main] o.s.b.w.embedded.tomcat.TomcatWebServer : Tomcat started on port(s): 51602 (http) with context path ''

INFO 7264 --- [ main] c.t.s.impl.TestProjectServiceImplTest : Started TestProjectServiceImplTest in 21.636 seconds (JVM running for 24.737)

INFO 7264 --- [ main] c.t.s.impl.TestProjectServiceImplTest :

我们可以看到，在Spring容器启动初期，会安装、启动一个mariadb4j并装载schema和data。

SpringBoot中的配置

在application-test.properties文件中使用如下配置，#Location of db files. delete this directory if you need to recreate from scratch

mariaDB4j.dataDir=./data/local

#Default is 3306, so using 3307 just in case it is already running on this machine

mariaDB4j.port=3307

app.mariaDB4j.databaseName=testdb

spring.datasource.url=jdbc:mariadb://localhost:3307/

spring.datasource.username=root

spring.datasource.password=

spring.datasource.driver-class-name=org.mariadb.jdbc.Driver

spring.jpa.database-platform=org.hibernate.dialect.MySQL5InnoDBDialect