spring+hibernate clear database after tests

I am trying to test adding Entity classes into database. But currently I can do it only once((( The second time I launch test, it fails((( Also I noticed that data is not cleared after test finished((( So next test just crashes because previuos data is still there. Code and message trace are below:

 @RunWith(SpringJUnit4ClassRunner.class)
    @ContextConfiguration(locations = {"classpath:application-context-test.xml"})
    @TestExecutionListeners({ DependencyInjectionTestExecutionListener.class,
        DirtiesContextTestExecutionListener.class,
        TransactionalTestExecutionListener.class,
        DbUnitTestExecutionListener.class })

@Transactional
public class HibernateAddingToBase {
    @Autowired
    SessionFactory sessionfactory;
    Session session;

    @Autowired
    DataSource dataSource;

    @Before
    public void setUp() throws MalformedURLException, SQLException, DatabaseUnitException {
        session = sessionfactory.getCurrentSession();
    }

    @Test
    @Rollback(false)
    @DatabaseSetup(value = "classpath:sampleData.xml") 
    @ExpectedDatabase(
            value = "classpath:ExpectedAddedCategories.xml",
            assertionMode = DatabaseAssertionMode.NON_STRICT
            )
    @DirtiesContext
    public void testAddCategories() {
        Category cat = new Category("sport");
        Category cat2 = new Category("art");
        Category cat3 = new Category("video");

        session.persist(cat);
        session.persist(cat2);
        session.persist(cat3);
    }

Exceptions:

org.hibernate.AssertionFailure: null id in data.Category entry (don't flush the Session after an exception occurs)
    at org.hibernate.event.internal.DefaultFlushEntityEventListener.checkId(DefaultFlushEntityEventListener.java:77)
    at org.hibernate.event.internal.DefaultFlushEntityEventListener.getValues(DefaultFlushEntityEventListener.java:192)
    at org.hibernate.event.internal.DefaultFlushEntityEventListener.onFlushEntity(DefaultFlushEntityEventListener.java:152)
    at org.hibernate.event.internal.AbstractFlushingEventListener.flushEntities(AbstractFlushingEventListener.java:231)
    at org.hibernate.event.internal.AbstractFlushingEventListener.flushEverythingToExecutions(AbstractFlushingEventListener.java:102)
    at org.hibernate.event.internal.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:55)
    at org.hibernate.internal.SessionImpl.flush(SessionImpl.java:1258)
    at org.hibernate.internal.SessionImpl.managedFlush(SessionImpl.java:425)
    at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.beforeTransactionCommit(JdbcTransaction.java:101)
    at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.commit(AbstractTransactionImpl.java:177)
    at org.springframework.orm.hibernate4.HibernateTransactionManager.doCommit(HibernateTransactionManager.java:584)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:761)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:730)
    at org.springframework.test.context.transaction.TransactionContext.endTransaction(TransactionContext.java:128)
    at org.springframework.test.context.transaction.TransactionalTestExecutionListener.afterTestMethod(TransactionalTestExecutionListener.java:218)
    at org.springframework.test.context.TestContextManager.afterTestMethod(TestContextManager.java:313)
    at org.springframework.test.context.junit4.statements.RunAfterTestMethodCallbacks.evaluate(RunAfterTestMethodCallbacks.java:93)
    at org.springframework.test.context.junit4.statements.SpringRepeat.evaluate(SpringRepeat.java:86)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:241)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:87)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:180)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192)

I tried to clean database with all suggested on inet solutions (@DirtiesContext, empty dataset file and so on) - they dont work here((( So my task is to make this test work each time I launch it. Any ideas?