Use embedded database for test in spring boot

Question

I have a spring boot application, it has a couple of @Entity classes and @RepositoryRestResource repositort interfaces for them. Now I want to write some tests, where I can check that I can add a new record into my database using those repositories, but I don't want to use my configured MySQL database for it, but instead I want to use some embedded db like H2. At the moment I have an application.properties file, which looks like this:

spring.jpa.hibernate.ddl-auto=create
spring.datasource.url=jdbc:mysql://localhost:3306/mydb
spring.datasource.username=root
spring.datasource.password=qwerty123

Question: How do I configure my app to use other db for tests? I have no xml in my project, everything is based on annotations. I tried to define @Configuration class with @Bean to create DataSource and then use it with @ContextConfiguration annotation on test class, but it says that it can't load context.

Answer 1

If you are using a Maven project, you can add a application.properties file into your src/test/resources, for example with the following content.

# Create DDL
spring.jpa.hibernate.ddl-auto=create

# H2 in local file system allowing other simultaneous connections
spring.datasource.url=jdbc:h2:~/test;AUTO_SERVER=TRUE

Also, you need to include H2 as dependency (pom.xml):

<dependency>
   <groupId>com.h2database</groupId>
   <artifactId>h2</artifactId>
   <version>1.4.193</version>
</dependency>