package ejb; import java.util.List; import javax.persistence.EntityManager; public abstract class AbstractFacade{ private Class entityClass; public AbstractFacade(Class entityClass) { this.entityClass = entityClass; } protected abstract EntityManager getEntityManager(); public void create(T entity) { getEntityManager().persist(entity); } public void edit(T entity) { getEntityManager().merge(entity); } public void remove(T entity) { getEntityManager().remove(getEntityManager().merge(entity)); } public T find(Object id) { return getEntityManager().find(entityClass, id); } public List findAll() { javax.persistence.criteria.CriteriaQuery cq = getEntityManager().getCriteriaBuilder().createQuery(); cq.select(cq.from(entityClass)); return getEntityManager().createQuery(cq).getResultList(); } public List findRange(int[] range) { javax.persistence.criteria.CriteriaQuery cq = getEntityManager().getCriteriaBuilder().createQuery(); cq.select(cq.from(entityClass)); javax.persistence.Query q = getEntityManager().createQuery(cq); q.setMaxResults(range[1] - range[0] + 1); q.setFirstResult(range[0]); return q.getResultList(); } public int count() { javax.persistence.criteria.CriteriaQuery cq = getEntityManager().getCriteriaBuilder().createQuery(); javax.persistence.criteria.Root rt = cq.from(entityClass); cq.select(getEntityManager().getCriteriaBuilder().count(rt)); javax.persistence.Query q = getEntityManager().createQuery(cq); return ((Long) q.getSingleResult()).intValue(); } }