public List<Contact> getContacts() {
        List<Contact> contacts = new ArrayList<Contact>();
        Transaction trns = null;
        Session session = HibernateUtil.getSessionFactory().openSession();
        try {
            trns = session.beginTransaction();
            contacts = (List) session.createQuery("from Contact").list();
       ...

@PersistenceContext
private EntityManager em;

public List<Contact> findAllConts() {

        Query query = entityManager.createQuery("SELECT e FROM Contact");
        return (List<Contact>) query.getResultList();
    }

   <persistence-unit name="Store" transaction-type="JTA">
        <provider>org.hibernate.ejb.HibernatePersistence</provider>
      <jta-data-source>jdbc/my_db</jta-data-source>   // glassfish
            <exclude-unlisted-classes>false</exclude-unlisted-classes>
        <properties>
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.hbm2ddl.auto" value="create" />
        </properties>
    </persistence-unit>
</persistence>

@PersistenceContext (unitName = "Store")
    private EntityManager em;

    public List<ContactEntity> getAllContacts(){

        List <ContactEntity> list = new ArrayList<ContactEntity>();

        TypedQuery<Contact> query = em.createNamedQuery("Contacts.getAll",Contact.class);
        list = query.getResultList();

       return list;
    }