Question

I am getting HibernateSystemException although I did everything that is mentioned on different forums.

Here is a part of applicationContext.xml

<bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource"/>
</bean>

I also placed @Transactional annotaion above my class.

@Transactional
public class MyClassImpl

Answer 1

A) this is the wrong transaction manager:

<bean id="transactionManager" 
class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
    <property name="dataSource" ref="dataSource"/>
</bean>

you need org.springframework.orm.hibernate3.HibernateTransactionManager, as you can see in 13.3.3 Hibernate > Declarative transaction demarcation.

DataSourceTransactionManager is for plain JDBC, not for Hibernate (see 12.3.8 JDBC > DataSourceTransactionManager).

B) you need this line also:

<tx:annotation-driven transaction-manager="transactionManager" />