Spring commits when it should not ? (related to Oracle autocommit)

Question

I have an interface like below

public interface FooDAO {
  public void callA(String x);
}

and an implementation as below deliberately making readonly true and not supported

public class FooDAOImpl implements FooDAO {

  //for testing
  @Transactional(readOnly = true, propagation = Propagation.NOT_SUPPORTED) 
  public void callA(String x) {
     //sql update method
  }
}

In my spring context, I declared the Datasource transaction manager and the tx:annotation-driven. I wrote a Junit4 test that looks like

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(...)
@TransactionConfiguration(transactionManager="txManager", defaultRollback=true)
public class MyTest {

    @Resource
    FooDAO fooDAO;

    @Test
    public void testRegisterWorker() {
        fooDAO.callA("")
    }
}

I would have expected the record to not be inserted into the database at all. However I see that the row has infact been inserted into the DB. I do use the Oracle database so I think the autocommit is set to true by default (I think). But shouldn't the spring transactional tags override them?

Can someone tell me what is going wrong here?

Answer 1

Hi Calm Storm,

Autocommit is a "feature" of JDBC, not Oracle (in Oracle all DML statements are part of a transaction, and thus are only commited when the application issues a commit).

Most drivers make autocommit the default when creating a connection to a database. You can change the behaviour of your connection by calling the setAutoCommit method.

Answer 2

In order to use @TransactionConfiguration you should annotate either your test class or test method @Transactional. Also your DAO method probably runs without transaction due to propagation = Propagation.NOT_SUPPORTED.

Answer 3

Autocommit probably is on by default. With DataSourceTransactionManager, autocommit is only changed if a transaction is actually started. Neither NOT_SUPPORTED or SUPPORTS start a transaction, so whatever default state the Connection is in will remain.

Consider setting autocommit off by default in your Spring xml file. If it is enabled, Spring will have to change it before each tx and restore it afterwards, which may be expensive in Oracle (not sure). This also prevents you from accidentally committing outside of a transaction.

For the details, see org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin() which manages the autocomit and isolation level of the Connection. doBegin() is only called by AbstractPlatformTransactionManager.getTransaction() and handleExistingTransaction() if the propagation is REQUIRED, REQUIRES_NEW or PROPAGATION_NESTED.

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You probably want to take a look at org.springframework.test.context.junit4.AbstractTransactionalJUnit4SpringContextTests. This is a Spring aware base class you can use for your test classes. It will rollback any transactions at the end of each test case. This way there is no need to change the annotations just for test. You can set your @Transactional the way they should be in prod and rely on the rollbacks to make sure nothing is actually changed in the db during the test.