Transaction Management

In the TestContext framework, transactions are managed by the TransactionalTestExecutionListener, which is configured by default, even if you do not explicitly declare @TestExecutionListeners on your test class. To enable support for transactions, however, you must configure a PlatformTransactionManager bean in the ApplicationContext that is loaded with @ContextConfiguration semantics (further details are provided later). In addition, you must declare Spring’s @Transactional annotation either at the class or the method level for your tests.

Test-managed Transactions

Test-managed transactions are transactions that are managed declaratively by using the TransactionalTestExecutionListener or programmatically by using TestTransaction (described later). You should not confuse such transactions with Spring-managed transactions (those managed directly by Spring within the ApplicationContext loaded for tests) or application-managed transactions (those managed programmatically within application code that is invoked by tests). Spring-managed and application-managed transactions typically participate in test-managed transactions. However, you should use caution if Spring-managed or application-managed transactions are configured with any propagation type other than REQUIRED or SUPPORTS (see the discussion on transaction propagation for details).

Preemptive timeouts and test-managed transactions

Caution must be taken when using any form of preemptive timeouts from a testing framework in conjunction with Spring’s test-managed transactions.

Specifically, Spring’s testing support binds transaction state to the current thread (via a java.lang.ThreadLocal variable) before the current test method is invoked. If a testing framework invokes the current test method in a new thread in order to support a preemptive timeout, any actions performed within the current test method will not be invoked within the test-managed transaction. Consequently, the result of any such actions will not be rolled back with the test-managed transaction. On the contrary, such actions will be committed to the persistent store — for example, a relational database — even though the test-managed transaction is properly rolled back by Spring.

Situations in which this can occur include but are not limited to the following.

  • JUnit 4’s @Test(timeout = …​) support and TimeOut rule

  • JUnit Jupiter’s assertTimeoutPreemptively(…​) methods in the org.junit.jupiter.api.Assertions class

  • TestNG’s @Test(timeOut = …​) support

Enabling and Disabling Transactions

Annotating a test method with @Transactional causes the test to be run within a transaction that is, by default, automatically rolled back after completion of the test. If a test class is annotated with @Transactional, each test method within that class hierarchy runs within a transaction. Test methods that are not annotated with @Transactional (at the class or method level) are not run within a transaction. Note that @Transactional is not supported on test lifecycle methods — for example, methods annotated with JUnit Jupiter’s @BeforeAll, @BeforeEach, etc. Furthermore, tests that are annotated with @Transactional but have the propagation attribute set to NOT_SUPPORTED or NEVER are not run within a transaction.

Table 1. @Transactional attribute support
Attribute Supported for test-managed transactions

value and transactionManager

yes

propagation

only Propagation.NOT_SUPPORTED and Propagation.NEVER are supported

isolation

no

timeout

no

readOnly

no

rollbackFor and rollbackForClassName

no: use TestTransaction.flagForRollback() instead

noRollbackFor and noRollbackForClassName

no: use TestTransaction.flagForCommit() instead

Method-level lifecycle methods — for example, methods annotated with JUnit Jupiter’s @BeforeEach or @AfterEach — are run within a test-managed transaction. On the other hand, suite-level and class-level lifecycle methods — for example, methods annotated with JUnit Jupiter’s @BeforeAll or @AfterAll and methods annotated with TestNG’s @BeforeSuite, @AfterSuite, @BeforeClass, or @AfterClass — are not run within a test-managed transaction.

If you need to run code in a suite-level or class-level lifecycle method within a transaction, you may wish to inject a corresponding PlatformTransactionManager into your test class and then use that with a TransactionTemplate for programmatic transaction management.

Note that AbstractTransactionalJUnit4SpringContextTests and AbstractTransactionalTestNGSpringContextTests are preconfigured for transactional support at the class level.

The following example demonstrates a common scenario for writing an integration test for a Hibernate-based UserRepository:

  • Java

  • Kotlin

@SpringJUnitConfig(TestConfig.class)
@Transactional
class HibernateUserRepositoryTests {

	@Autowired
	HibernateUserRepository repository;

	@Autowired
	SessionFactory sessionFactory;

	JdbcTemplate jdbcTemplate;

	@Autowired
	void setDataSource(DataSource dataSource) {
		this.jdbcTemplate = new JdbcTemplate(dataSource);
	}

	@Test
	void createUser() {
		// track initial state in test database:
		final int count = countRowsInTable("user");

		User user = new User(...);
		repository.save(user);

		// Manual flush is required to avoid false positive in test
		sessionFactory.getCurrentSession().flush();
		assertNumUsers(count + 1);
	}

	private int countRowsInTable(String tableName) {
		return JdbcTestUtils.countRowsInTable(this.jdbcTemplate, tableName);
	}

	private void assertNumUsers(int expected) {
		assertEquals("Number of rows in the [user] table.", expected, countRowsInTable("user"));
	}
}
@SpringJUnitConfig(TestConfig::class)
@Transactional
class HibernateUserRepositoryTests {

	@Autowired
	lateinit var repository: HibernateUserRepository

	@Autowired
	lateinit var sessionFactory: SessionFactory

	lateinit var jdbcTemplate: JdbcTemplate

	@Autowired
	fun setDataSource(dataSource: DataSource) {
		this.jdbcTemplate = JdbcTemplate(dataSource)
	}

	@Test
	fun createUser() {
		// track initial state in test database:
		val count = countRowsInTable("user")

		val user = User()
		repository.save(user)

		// Manual flush is required to avoid false positive in test
		sessionFactory.getCurrentSession().flush()
		assertNumUsers(count + 1)
	}

	private fun countRowsInTable(tableName: String): Int {
		return JdbcTestUtils.countRowsInTable(jdbcTemplate, tableName)
	}

	private fun assertNumUsers(expected: Int) {
		assertEquals("Number of rows in the [user] table.", expected, countRowsInTable("user"))
	}
}

As explained in Transaction Rollback and Commit Behavior, there is no need to clean up the database after the createUser() method runs, since any changes made to the database are automatically rolled back by the TransactionalTestExecutionListener.

Transaction Rollback and Commit Behavior

By default, test transactions will be automatically rolled back after completion of the test; however, transactional commit and rollback behavior can be configured declaratively via the @Commit and @Rollback annotations. See the corresponding entries in the annotation support section for further details.

Programmatic Transaction Management

You can interact with test-managed transactions programmatically by using the static methods in TestTransaction. For example, you can use TestTransaction within test methods, before methods, and after methods to start or end the current test-managed transaction or to configure the current test-managed transaction for rollback or commit. Support for TestTransaction is automatically available whenever the TransactionalTestExecutionListener is enabled.

The following example demonstrates some of the features of TestTransaction. See the javadoc for TestTransaction for further details.

  • Java

  • Kotlin

@ContextConfiguration(classes = TestConfig.class)
public class ProgrammaticTransactionManagementTests extends
		AbstractTransactionalJUnit4SpringContextTests {

	@Test
	public void transactionalTest() {
		// assert initial state in test database:
		assertNumUsers(2);

		deleteFromTables("user");

		// changes to the database will be committed!
		TestTransaction.flagForCommit();
		TestTransaction.end();
		assertFalse(TestTransaction.isActive());
		assertNumUsers(0);

		TestTransaction.start();
		// perform other actions against the database that will
		// be automatically rolled back after the test completes...
	}

	protected void assertNumUsers(int expected) {
		assertEquals("Number of rows in the [user] table.", expected, countRowsInTable("user"));
	}
}
@ContextConfiguration(classes = [TestConfig::class])
class ProgrammaticTransactionManagementTests : AbstractTransactionalJUnit4SpringContextTests() {

	@Test
	fun transactionalTest() {
		// assert initial state in test database:
		assertNumUsers(2)

		deleteFromTables("user")

		// changes to the database will be committed!
		TestTransaction.flagForCommit()
		TestTransaction.end()
		assertFalse(TestTransaction.isActive())
		assertNumUsers(0)

		TestTransaction.start()
		// perform other actions against the database that will
		// be automatically rolled back after the test completes...
	}

	protected fun assertNumUsers(expected: Int) {
		assertEquals("Number of rows in the [user] table.", expected, countRowsInTable("user"))
	}
}

Running Code Outside of a Transaction

Occasionally, you may need to run certain code before or after a transactional test method but outside the transactional context — for example, to verify the initial database state prior to running your test or to verify expected transactional commit behavior after your test runs (if the test was configured to commit the transaction). TransactionalTestExecutionListener supports the @BeforeTransaction and @AfterTransaction annotations for exactly such scenarios. You can annotate any void method in a test class or any void default method in a test interface with one of these annotations, and the TransactionalTestExecutionListener ensures that your before transaction method or after transaction method runs at the appropriate time.

Any before methods (such as methods annotated with JUnit Jupiter’s @BeforeEach) and any after methods (such as methods annotated with JUnit Jupiter’s @AfterEach) are run within a transaction. In addition, methods annotated with @BeforeTransaction or @AfterTransaction are not run for test methods that are not configured to run within a transaction.

Configuring a Transaction Manager

TransactionalTestExecutionListener expects a PlatformTransactionManager bean to be defined in the Spring ApplicationContext for the test. If there are multiple instances of PlatformTransactionManager within the test’s ApplicationContext, you can declare a qualifier by using @Transactional("myTxMgr") or @Transactional(transactionManager = "myTxMgr"), or TransactionManagementConfigurer can be implemented by an @Configuration class. Consult the javadoc for TestContextTransactionUtils.retrieveTransactionManager() for details on the algorithm used to look up a transaction manager in the test’s ApplicationContext.

Demonstration of All Transaction-related Annotations

The following JUnit Jupiter based example displays a fictitious integration testing scenario that highlights all transaction-related annotations. The example is not intended to demonstrate best practices but rather to demonstrate how these annotations can be used. See the annotation support section for further information and configuration examples. Transaction management for @Sql contains an additional example that uses @Sql for declarative SQL script execution with default transaction rollback semantics. The following example shows the relevant annotations:

  • Java

  • Kotlin

@SpringJUnitConfig
@Transactional(transactionManager = "txMgr")
@Commit
class FictitiousTransactionalTest {

	@BeforeTransaction
	void verifyInitialDatabaseState() {
		// logic to verify the initial state before a transaction is started
	}

	@BeforeEach
	void setUpTestDataWithinTransaction() {
		// set up test data within the transaction
	}

	@Test
	// overrides the class-level @Commit setting
	@Rollback
	void modifyDatabaseWithinTransaction() {
		// logic which uses the test data and modifies database state
	}

	@AfterEach
	void tearDownWithinTransaction() {
		// run "tear down" logic within the transaction
	}

	@AfterTransaction
	void verifyFinalDatabaseState() {
		// logic to verify the final state after transaction has rolled back
	}

}
@SpringJUnitConfig
@Transactional(transactionManager = "txMgr")
@Commit
class FictitiousTransactionalTest {

	@BeforeTransaction
	fun verifyInitialDatabaseState() {
		// logic to verify the initial state before a transaction is started
	}

	@BeforeEach
	fun setUpTestDataWithinTransaction() {
		// set up test data within the transaction
	}

	@Test
	// overrides the class-level @Commit setting
	@Rollback
	fun modifyDatabaseWithinTransaction() {
		// logic which uses the test data and modifies database state
	}

	@AfterEach
	fun tearDownWithinTransaction() {
		// run "tear down" logic within the transaction
	}

	@AfterTransaction
	fun verifyFinalDatabaseState() {
		// logic to verify the final state after transaction has rolled back
	}

}
Avoid false positives when testing ORM code

When you test application code that manipulates the state of a Hibernate session or JPA persistence context, make sure to flush the underlying unit of work within test methods that run that code. Failing to flush the underlying unit of work can produce false positives: Your test passes, but the same code throws an exception in a live, production environment. Note that this applies to any ORM framework that maintains an in-memory unit of work. In the following Hibernate-based example test case, one method demonstrates a false positive, and the other method correctly exposes the results of flushing the session:

  • Java

  • Kotlin

// ...

@Autowired
SessionFactory sessionFactory;

@Transactional
@Test // no expected exception!
public void falsePositive() {
	updateEntityInHibernateSession();
	// False positive: an exception will be thrown once the Hibernate
	// Session is finally flushed (i.e., in production code)
}

@Transactional
@Test(expected = ...)
public void updateWithSessionFlush() {
	updateEntityInHibernateSession();
	// Manual flush is required to avoid false positive in test
	sessionFactory.getCurrentSession().flush();
}

// ...
// ...

@Autowired
lateinit var sessionFactory: SessionFactory

@Transactional
@Test // no expected exception!
fun falsePositive() {
	updateEntityInHibernateSession()
	// False positive: an exception will be thrown once the Hibernate
	// Session is finally flushed (i.e., in production code)
}

@Transactional
@Test(expected = ...)
fun updateWithSessionFlush() {
	updateEntityInHibernateSession()
	// Manual flush is required to avoid false positive in test
	sessionFactory.getCurrentSession().flush()
}

// ...

The following example shows matching methods for JPA:

  • Java

  • Kotlin

// ...

@PersistenceContext
EntityManager entityManager;

@Transactional
@Test // no expected exception!
public void falsePositive() {
	updateEntityInJpaPersistenceContext();
	// False positive: an exception will be thrown once the JPA
	// EntityManager is finally flushed (i.e., in production code)
}

@Transactional
@Test(expected = ...)
public void updateWithEntityManagerFlush() {
	updateEntityInJpaPersistenceContext();
	// Manual flush is required to avoid false positive in test
	entityManager.flush();
}

// ...
// ...

@PersistenceContext
lateinit var entityManager:EntityManager

@Transactional
@Test // no expected exception!
fun falsePositive() {
	updateEntityInJpaPersistenceContext()
	// False positive: an exception will be thrown once the JPA
	// EntityManager is finally flushed (i.e., in production code)
}

@Transactional
@Test(expected = ...)
void updateWithEntityManagerFlush() {
	updateEntityInJpaPersistenceContext()
	// Manual flush is required to avoid false positive in test
	entityManager.flush()
}

// ...
Testing ORM entity lifecycle callbacks

Similar to the note about avoiding false positives when testing ORM code, if your application makes use of entity lifecycle callbacks (also known as entity listeners), make sure to flush the underlying unit of work within test methods that run that code. Failing to flush or clear the underlying unit of work can result in certain lifecycle callbacks not being invoked.

For example, when using JPA, @PostPersist, @PreUpdate, and @PostUpdate callbacks will not be called unless entityManager.flush() is invoked after an entity has been saved or updated. Similarly, if an entity is already attached to the current unit of work (associated with the current persistence context), an attempt to reload the entity will not result in a @PostLoad callback unless entityManager.clear() is invoked before the attempt to reload the entity.

The following example shows how to flush the EntityManager to ensure that @PostPersist callbacks are invoked when an entity is persisted. An entity listener with a @PostPersist callback method has been registered for the Person entity used in the example.

  • Java

  • Kotlin

// ...

@Autowired
JpaPersonRepository repo;

@PersistenceContext
EntityManager entityManager;

@Transactional
@Test
void savePerson() {
	// EntityManager#persist(...) results in @PrePersist but not @PostPersist
	repo.save(new Person("Jane"));

	// Manual flush is required for @PostPersist callback to be invoked
	entityManager.flush();

	// Test code that relies on the @PostPersist callback
	// having been invoked...
}

// ...
// ...

@Autowired
lateinit var repo: JpaPersonRepository

@PersistenceContext
lateinit var entityManager: EntityManager

@Transactional
@Test
fun savePerson() {
	// EntityManager#persist(...) results in @PrePersist but not @PostPersist
	repo.save(Person("Jane"))

	// Manual flush is required for @PostPersist callback to be invoked
	entityManager.flush()

	// Test code that relies on the @PostPersist callback
	// having been invoked...
}

// ...

See JpaEntityListenerTests in the Spring Framework test suite for working examples using all JPA lifecycle callbacks.