Spring Test helpfully rolls back any changes made to the database within a test method. This means that it is not necessary to take the time to delete/reload the test data
Methods annotated with @BeforeTransaction run, like its name suggests, before the transaction of each test is started. If in such method you can detect if the test data is loaded, then one can load the data when needed.
Beware though that the data is left in your (in-memory) database for all subsequent tests.
We use this to load "static" data that would, in a production environment, also be bootstrapped into our database when starting it. This way we actually use exactly the same code and data for our tests, rather than relying on (DbUnit) exports that might become outdated.
We use DBUnit in conjunction with Spring Test extensively. But we do not use the DBUnit functionality to delete data at the end of the test.
We put a bunch of DBUnit inserts for our test data in the @Before method to initialise the test. Then when the test is complete we let the spring rollback functionality bring the database back to its original state.
The biggest problem we have with this is that the DBUnit data has to be loaded before each test, which can be a major performance hit. Most of our tests using DBUnit are read only, testing the behaviour of the application based on certain predefined behaviour. So we have a habit of creating master tests that then run all the fine grain tests in a batch within the same transaction.
One approach that works is to create a "data initialiser" class, add it to a test Spring application context that also has your data source, and wire this application context into your tests. This relies on the fact that Spring caches the application context between test invocations.
For example, a test superclass:
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations={"classpath:test-application-context.xml"})
@Transactional
public abstract class DataLoadingTest {
@Autowired
protected DatabaseInitialiser databaseInitialiser;
}
With test-application-context.xml
:
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="dataSource" .../>
<bean class="DatabaseInitialiser">
<property name="dataSource" ref="dataSource"/>
</bean>
</beans>
And
public class DatabaseInitialiser extends JdbcDaoSupport {
@PostConstruct
public void load() {
// Initialise your database here: create schema, use DBUnit to load data, etc.
}
}
In this example:
DataLoadingTest
;DatabaseInitialiser.load()
, via the @PostConstruct
annotation;DatabaseInitialiser
from the application context, which is already cached;Likewise, DatabaseInitialiser
can have a method annotated @PostDestroy
to perform any rollback necessary at the end of the whole test run.
Spring Test and DbUnit is two excellent frameworks. But it doesn't make sense to combine them. Since Spring Test execute a rollback on the connection, it cleans up afterwards, while DbUnit cleans up and insert test data in the @Before
method.
Use Spring if you're not dependent on any dynamic data and dbUnit otherwise.