public <T> T getByCriteria(Class<T> clazz, String field, Object o) {
        Session session = sessionFactory.openSession();
        CriteriaBuilder builder = session.getCriteriaBuilder();
        CriteriaQuery<T> query = builder.createQuery(clazz);
        Root<T> root = query.from(clazz);


        T entity = session.createQuery(query.where(builder.equal(root.get(field), o)).select(root)).getSingleResult();
        session.close();

        return entity;
    }

    public <T> List<T> getAll(Class<T> clazz) {
        Session session = sessionFactory.openSession();
        CriteriaBuilder builder = session.getCriteriaBuilder();
        CriteriaQuery<T> query = builder.createQuery(clazz);

        List<T> list = session.createQuery(query.select(query.from(clazz))).getResultList();
        session.close();
        return list;
    }

    public <T> void save(T entity) {
        Session session = sessionFactory.openSession();

        session.beginTransaction();
        session.saveOrUpdate(entity);
        session.getTransaction().commit();

        session.close();
    }

    public <T> void clear(Class<T> clazz) {
        List<T> entities = getAll(clazz);

        Session session = sessionFactory.openSession();

        session.beginTransaction();

        for(T entity : entities) {
            session.delete(entity);
        }

        session.getTransaction().commit();

        session.close();
    }