Spring 3, Hibernate 4 AutoWired sessionFactory with Generic DAO - spring-mvc

Question

Using Spring MVC 3 & Hibernate 4 I'm getting:
java.lang.NullPointerException
com.daniel.rr.dao.common.DAOImpl.getSession(DAOImpl.java:22)
com.daniel.rr.dao.common.DAOImpl.save(DAOImpl.java:27)
com.daniel.rr.controller.HelloController.printWelcome(HelloController.java:30)
This is the relevant spring configuration:
<context:annotation-config />
<tx:annotation-driven transaction-manager="transactionManager" />
<bean id="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
<property name="packagesToScan">
<list>
<value>com.daniel.rr.model</value>
<value>com.daniel.rr.dao</value>
<value>com.daniel.rr.dao.common</value>
<value>com.daniel.rr.controller</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
<prop key="hibernate.show_sql">true</prop>
<prop key="hibernate.hbm2ddl.auto">update</prop>
</props>
</property>
<property name="dataSource" ref="dataSource" />
</bean>
<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="url" value="jdbc:mysql://localhost:3306/rr" />
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="username" value="root" />
<property name="password" value="" />
</bean>
<bean name="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
<property name="sessionFactory" ref="sessionFactory" />
</bean>
Generic DAO:
public interface DAO<T> {
T save(T t);
void delete(T t);
}
#Transactional
public abstract class DAOImpl<T> implements DAO<T> {
#Autowired
private SessionFactory sessionFactory;
public void setSessionFactory(SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
public Session getSession() {
return sessionFactory.getCurrentSession();
}
#Override
public T save(T t) {
getSession().persist(t);
return t;
}
#Override
public void delete(T t) {
getSession().delete(t);
}
}
AccountDAO:
public class AccountDAO extends DAOImpl<Account> implements DAO<Account> {
}
MVC Controller:
public class HelloController {
#RequestMapping(method = RequestMethod.GET)
public String printWelcome(ModelMap model) {
//System.out.println("is null? " + sessionFactory);
AccountDAO dao = new AccountDAO();
Account account = new Account();
account.setUsername("hello");
account.setPassword("test");
dao.save(account);
model.addAttribute("message", "Hello world!");
return "hello";
}
}
I've searched thru StackOverflow and Google but I cannot find anything that helps.
I've tried using a Transaction on DAOImpl.save(T t) but it still has the same issue.
public T save(T t) {
Transaction tr = getSession().getTransaction();
tr.begin();
getSession().persist(t);
tr.commit();
return t;
}

Answer 1

Annotations are not inherited.
Add the transactional annotation to the concrete dao, not the abstract class.
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