Spring profiles can be used for this. This would be a specific way:
Have environment specific properties files:
application.properties:
spring.profiles.active: dev
application-dev.properties
spring.jpa.database: MYSQL
spring.jpa.hibernate.ddl-auto: update
spring.datasource.url: jdbc:mysql://localhost:3306/dbname
spring.datasource.username: username
spring.datasource.password: password
application-test.properties
spring.jpa.database: HSQL
Have both MySQL and H2 drivers in pom.xml, like this:
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<scope>test</scope>
</dependency>
Last but not the least, annotate Test classes with @ActiveProfiles("test").