public class DataAccessController implements Serializable {

    @PersistenceContext(name = "em")
    protected EntityManager em;
    @Resource
    private UserTransaction utx;

    public  void create(T entity) {
        try {
            utx.begin();
            em.persist(entity);
            utx.commit();
        } catch (Exception e) {
            try {
                utx.rollback();
            } catch (SystemException ex) {
                //
            }
            throw new RuntimeException(e);
        }
    }

    public  void edit(T entity) {
        try {
            utx.begin();
            em.merge(entity);
            utx.commit();
        } catch (Exception e) {
            try {
                utx.rollback();
            } catch (SystemException ex) {
                //
            }
            throw new RuntimeException(e);
        }
    }

    public  void remove(T entity) {
        try {
            utx.begin();
            em.remove(em.merge(entity));
            utx.commit();
        } catch (Exception e) {
            try {
                utx.rollback();
            } catch (SystemException ex) {
                //
            }
            throw new RuntimeException(e);
        }
    }

    public  T find(Class clazz, Object id) {
        return em.find(clazz, id);
    }

    public Query createQuery(String query) {
        return em.createNamedQuery(query);
    }

    public  List findAll(Class clazz) {
        CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
        cq.select(cq.from(clazz));
        return em.createQuery(cq).getResultList();
    }

    public  List findRange(Class clazz, int begin, int end) {
        CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
        cq.select(cq.from(clazz));
        Query q = em.createQuery(cq);
        q.setMaxResults(end - begin);
        q.setFirstResult(begin);
        return q.getResultList();
    }

    public  int count(Class clazz) {
        CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
        Root rt = cq.from(clazz);
        cq.select(em.getCriteriaBuilder().count(rt));
        Query q = em.createQuery(cq);
        return ((Long) q.getSingleResult()).intValue();
    }
}

But I’m having trouble using DataAccessController, cant’ find it anywere…
Please advise where to find this utility class.

/Kent

There may be more elegant solutions using the standard components and JS libraries, and there’s certainly third party solutions like a4j:poll, but the above should get you heading in the right direction.

I thought this would be the most obvious example of the use of ajax with with data tables as it is a common desire to display up to date data.

previously i used a4jsf:poll

it amazes me how people who write articles and manuals seem to be always on a different wavelength

It’s solved if you use the ViewScope.