Using TransactionProxyFactoryBean with Spring and Hibernate

Question

I have an old project that I'm trying to upgrade to spring 4 / hibernate 4.

We use this approach to configuring our transactions.

That is to say, in XML we define a transaction manager like:

<bean id="abstractTransactionProxy"
abstract="true"
class="org.springframework.transaction.interceptor.TransactionProxyFactoryBean">
<property name="transactionManager" ref="hibernateTransactionManager"/>
<property name="transactionAttributes">
    <props>
        <prop key="create*">PROPAGATION_REQUIRED</prop>
        <prop key="update*">PROPAGATION_REQUIRED</prop>
        <prop key="delete*">PROPAGATION_REQUIRED</prop>
        <prop key="*">PROPAGATION_SUPPORTS,readOnly</prop>
    </props>
</property>

and

<bean id="MySessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    <property name="dataSource"     ref="myDataSource" />
    <property name="configLocation" value="WEB-INF/hibernate.cfg.xml" />
</bean>

and then each of our service beans are defined like:

<bean id="customerService" parent="abstractTransactionProxy">
    <property name="target" ref="customerTarget"/>
    <property name="personDAO" ref="personDAO" />
</bean>

and the DAOs are defined like:

    <alias name="personDaoImpl" alias="personDAO"/>
<bean id="personDaoImpl" 
    class="com.foo.bar.hibernate.PersonDaoImpl">
    <property name="sessionFactory" ref="MySessionFactory" />
</bean>

PersonDaoImpl (and all the other DAOs) have many methods that look like this (all of the DAOs extend HibernateDaoSupport):

    public List<Person> getPersonByCriteria(final String criteria) {
    List<Person> results = 
        (List<Person>) this.getHibernateTemplate().executeFind(new HibernateCallback<List<Person>>(){

        public List<Person> doInHibernate(Session session) throws HibernateException, SQLException {
            List<Person> results = (List<Person>) session.createQuery(MYSQLHERE).setString("criteria", criteria).list();
            return results;
        }
    });
    return results;
}

Now, the problem I Face at this point is getting rid of our dependency on extending our DAOs from HibernateDaoSupport, and by extension, on using it's HibernateTemplate helper object.

Here's the steps I've taken:

• Simply remove them from the DAO methods - don't extend HibernateDaoSupport, remove the HibernateTemplate callback. This looks like:

      public List<Person> getPersonByCriteria(final String criteria) {
          List<Person> results = (List<Person>) getSessionFactory().getCurrentSession().createQuery(MYSQLHERE).setString("criteria", criteria).list();
  
          return results;
      }
  

Of course this gives me compile-time errors because 'getSessionFactory' was part of the base class 'HibernateDaoSupport' which I just removed.

• So I implemented a 'MyHibernateDaoSupport' Class, and had my DAO extend that instead. It looks like:

  public class MyHibernateDaoSupport {
  
      private SessionFactory sessionFactory;
      protected Session session;
      protected static Logger logger = Logger.getLogger(MyHibernateDaoSupport.class);
  
      public void setSessionFactory(SessionFactory sessionFactory) {
          this.sessionFactory = sessionFactory;
          session = this.sessionFactory.getCurrentSession();
      }
  
      public SessionFactory getSessionFactory() {
      return this.sessionFactory;
      }
  
      public Session getHibernateTemplate() {
          session = this.sessionFactory.getCurrentSession();
          return session;
      }
  
      public MyHibernateDaoSupport() {
      }
  

  }

Now I can build, deploy and run and I hit this error message:

No session available in this thread

How can I make this work?

• In simple terms, what was the 'hibernateCallback()', and it's anoymous inner class actually doing?

• How can I make my project's transactions work as before, without using HibernateDaoSupport and HibernateTemplate classes?

I've tried tagging my 'CustomerService' (the business logic object that calls 'PersonDao') with @transactional but (A) I see the same error regardless and (B) I'd really prefer to be able to do this programmatically, to reduce the scale of changes to the way the code works now. I also tried putting the transactions at the DAO level instead, and met the same issue.

Apologies if that was way too much detail for the Stack overflow format.

Answer 1

1. You need to inject the SessionFactory into your DAO classes:

   @Repository
   public class PersonDAOImpl implements PersonDAO {
   
       @Autowired
       private SessionFactory sessionFactory;
   
       public List<Person> getPersonByCriteria(final String criteria) {
           List<Person> results = (List<Person>) getSessionFactory().getCurrentSession().createQuery(MYSQLHERE).setString("criteria", criteria).list();
           return results;
       }
   }
   

2. Add @Transactional to your service methods

3. Add HibernateTransactionManager

4. Instruct Spring to use declarative transactions:

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

5. Make sure you use LocalSessionFactoryBean for creating the SessionFactory

Here's a detailed step-by-step tutorial for configuring Spring and Hibernate 4