JarCastingIntroduction
spring-testcontainer provides integration between the Spring (Data JPA) testing framework and Testcontainer library to easily test your application with different containerized database instances.
Configuration
The simplest way to start is to use the annotation @SpringContainerTestDatabase on your test class and add a static container attribute that exposes a JDBC connection:
@Container
static MySQLContainer container = new MySQLContainer("mysql");
and another one that will setup the Spring context:
@AnnotationContextCustomizer
static ContextCustomizer customizer = new JdbcDbContainerContextCustomizer(container);
The lifecycle of the container is managed by the Testcontainer library itself.
Don't forget to add as dependencies the Testcontainers library of the db you want to use and the associated JDBC driver library, for instance for MySQL:
<dependency>
<groupId>org.testcontainers</groupId>
<artifactId>mysql</artifactId>
<version>1.15.0</version>
<scope>test</scope>
</dependency>
Driver dependency:
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.22</version>
</dependency>
If you want to customize the properties datasource, you can extend and override JdbcDbContainerContextCustomizer#getProperties.
Example
@Transactional
@SpringContainerTestDatabase
class TestMySQL {
@Container
static MySQLContainer container = new MySQLContainer("mysql");
@AnnotationContextCustomizer
static ContextCustomizer customizer = new JdbcDbContainerContextCustomizer(container);
@Autowired
CustomerRepository customerRepository;
@Test
void test() {
Customer c = new Customer();
c.setFirstname("admin");
c.setLastname("admin");
this.customerRepository.save(c);
Assertions.assertEquals(1, this.customerRepository.findAll().size()); // Whatever...
}
}
Maven
To add a dependency on spring-testcontainer using Maven, use the following:
<dependency>
<groupId>me.paulbares</groupId>
<artifactId>spring-testcontainer</artifactId>
<version>1.0.1</version>
</dependency>
Important
Per test class, only one field annotated with @Container is expected and this field must be static meaning only one docker container will be started for all the tests within this class. DON'T FORGET to add a ContextCustomizer to your class otherwise your datasource will be misconfigured and Spring will fall back to an embedded in-memory H2 database.
FAQ
- How can I check my test is correctly setup? You can verify in your test the connection url with the datasource:
@Autowired
DataSource dataSource;
...
String url = this.dataSource.getConnection().getMetaData().getURL(); // Value is jdbc:mysql://localhost:33349/test for a mysql db.