<p:dataTable value="#{productListMg.productsListLazy}"
                     lazy="true"
                     paginatorPosition="top"
                     paginator="true"
                     paginatorAlwaysVisible="false"
                     rows="12"
                     var="prd" rowIndexVar="rowIndex" id="productTb"
                     styleClass="horizontal-line-table inline-button">

@ManagedBean
@ViewScoped
public class ProductListMg {
    public ProductListMg()
    {
        productsListLazy=new NamingBaseLazyModel(Product.class);
    }
}

@Override
    public List load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String, Object> filters) {
        return NamingDl.getInstance().loadNamingObjectsLazy(cls, first, pageSize, sortField, sortOrder, filters);
    }

    @Override
    public int getRowCount() {
        return NamingDl.getInstance().getNamingLazyObjectSize(cls);
    }

public int getNamingLazyObjectSize(Class cls) {
        Session session = getSessionFactory().openSession();
        int rc = 0;
        try {
            Criteria crit = session.createCriteria(cls);

            crit.setProjection(Projections.rowCount());
            List l=crit.list();
            if (l!=null && l.size()>0) {
                Long rc2 = (Long)l.get(0);
                if (rc2 != null)
                    rc = rc2.intValue();
                return rc;
            }
        } catch (Exception ex) {
            ex.printStackTrace();
        } finally {
            session.close();
        }
        return 0;
    }