ReaderFacade.java

package fi.insomnia.bortal.facade;

import javax.ejb.LocalBean;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.TypedQuery;

import fi.insomnia.bortal.model.LanEvent;
import fi.insomnia.bortal.model.Reader;

@Stateless
@LocalBean
public class ReaderFacade extends EventChildGenericFacade<Reader> {

    @PersistenceContext
    private EntityManager em;

    public ReaderFacade() {
        super(Reader.class);
    }

    protected EntityManager getEm() {
        return em;
    }

    public Reader findByIdent(LanEvent event, String reader) {
        TypedQuery<Reader> q = em.createQuery("select r from Reader r where r.id.eventId = :eventid and r.identification = :ident", Reader.class);
        q.setParameter("eventid", event.getId());
        q.setParameter("ident", reader);
        return getSingleNullableResult(q);
    }

    public Reader findOrCreateByIdent(LanEvent ev, String ident) {
        Reader ret = findByIdent(ev, ident);
        if (ret == null) {
            ret = createIdent(this, ev, ident);
        }
        return ret;
    }

    private static synchronized Reader createIdent(ReaderFacade rf, LanEvent ev, String ident) {
        Reader ret = rf.findByIdent(ev, ident);
        if (ret == null) {
            ret = new Reader(ev, ident);
            ret.setDescription("Automagically created");
            rf.create(ret);
        }
        return ret;
    }
}