getSession hibernate sempre NULL utilizando Spring @Autowired

public interface DaoI<T> {
	
	public void persistir(T objeto);
	
	public void excluir (T objeto);
	
	public T get(Integer id);
	
	public List<T> listar(int de, int ate);

}

	public void addUsuario(Usuario usuario);
	
	public void removerUsuario(Usuario usuario);
	
	public Usuario getUsuario(Integer id);
	
	public void atualizaUsuario(Usuario usuario);
	
	public List<Usuario> getUsuarios();

}

@Transactional(propagation=Propagation.SUPPORTS)
public abstract class DaoGenerico<T> implements DaoI<T> {
	
	@Autowired
	private SessionFactory sessionFactory;
	
	private Session getSession(){return getSessionFactory().getCurrentSession();}

	public SessionFactory getSessionFactory() {return sessionFactory;}

	public void setSessionFactory(SessionFactory sessionFactory) {this.sessionFactory = sessionFactory;}
	
	@SuppressWarnings("rawtypes")
	protected abstract Class getClazz();

	public void persistir(T objeto) {
		getSession().persist(objeto);
	}

	public void excluir(T objeto) {
		getSession().delete(objeto);
		
	}

	@SuppressWarnings("unchecked")
	public T get(Integer id) {
		return (T) getSession().get(getClazz(), id);

	}

	@SuppressWarnings("unchecked")
	public List<T> listar(int de, int ate) {
		return (List<T>) getSession().createCriteria(getClazz()).setMaxResults(ate).setFirstResult(de).list();

	}
	
	@SuppressWarnings("unchecked")
	public List<T> listar() {
		return (List<T>) getSession().createCriteria(getClazz()).list();

	}

@Transactional(propagation=Propagation.SUPPORTS)
@Repository("daoUsuario")
public class DaoUsuario extends DaoGenerico<Usuario> implements DaoUsuarioI {


	public void addUsuario(Usuario usuario) {
		persistir(usuario);
	}

	public void removerUsuario(Usuario usuario) {
		removerUsuario(usuario);
	}

	public Usuario getUsuario(Integer id) {
		return get(id);
	}

	public void atualizaUsuario(Usuario usuario) {
		Session s = super.getSessionFactory().getCurrentSession();
		s.update(usuario);
	}

	public List<Usuario> getUsuarios() {
		return listar();
	}

	@SuppressWarnings("rawtypes")
	protected Class getClazz() {
		return Usuario.class;
	}

}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:aop="http://www.springframework.org/schema/aop"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:jee="http://www.springframework.org/schema/jee"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
		http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.1.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd
		http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.1.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.1.xsd">
		
		
		<context:annotation-config />
		
		<context:component-scan base-package="br.com.springframework.persistencia" />
		
		<bean id="transactionManager" class="org.springframework.orm.hibernate4.HibernateTransactionManager">
			<property name="sessionFactory" ref="sessionFactory"/>
		</bean>
		
		<tx:annotation-driven transaction-manager="transactionManager"/>
	
		<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
			<property name="driverClass" value="com.mysql.jdbc.Driver"/>
			<property name="user" value="*******" />
			<property name="password" value="********" />
			<property name="jdbcUrl" value="jdbc:mysql://localhost:3306/springframework"/>
			
			<property name="maxPoolSize" value="30" />
			<property name="acquireIncrement" value="1"/>
			<property name="maxIdleTime" value="120"/>
			<property name="acquireRetryAttempts" value="10"/>
			<property name="initialPoolSize" value="1" />
		</bean> 
		
		<bean id="sessionFactory" name="sessionFactory" class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
			<property name="dataSource" ref="dataSource"/>
			<property name="packagesToScan" value="br.com.springframework.entidades" />
			<property name="hibernateProperties">
				<props>
					<prop key="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</prop>
					<prop key="hibernate.hbm2ddl.auto">update</prop>
				</props>
			</property>
		</bean>
		
		
		
		<bean class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor"/>
</beans>