GenericFacade.java 4.64 KB
package fi.insomnia.bortal.facade;

import java.util.ArrayList;
import java.util.List;

import javax.persistence.EntityManager;
import javax.persistence.NoResultException;
import javax.persistence.TypedQuery;
import javax.persistence.criteria.CriteriaBuilder;
import javax.persistence.criteria.CriteriaQuery;
import javax.persistence.criteria.Path;
import javax.persistence.criteria.Predicate;
import javax.persistence.criteria.Root;
import javax.persistence.metamodel.SingularAttribute;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import fi.insomnia.bortal.model.ModelInterface;

/**
 * Session Bean implementation class GenericFacade
 */
public abstract class GenericFacade<PK, T extends ModelInterface> {

    private static final Logger logger = LoggerFactory.getLogger(GenericFacade.class);

    private Class<T> entClass;

    public GenericFacade(Class<T> entityClass) {
        this.entClass = entityClass;
    }

    protected Class<T> getEntityClass() {
        return entClass;
    }

    protected abstract EntityManager getEm();

    public void create(T entity) {
        getEm().persist(entity);
    }

    public void remove(T entity) {
        getEm().remove(entity);
    }

    public T merge(T entity) {
        return getEm().merge(entity);

    }

    public T find(PK id) {
        T ret = getEm().find(getEntityClass(), id);
        return ret;
    }

    public List<T> findAll() {
        CriteriaBuilder cb = getEm().getCriteriaBuilder();
        CriteriaQuery<T> cq = cb.createQuery(getEntityClass());
        Root<T> root = cq.from(getEntityClass());
        cq.orderBy(cb.asc(root.get("id")));

        cq.select(root);
        return getEm().createQuery(cq).getResultList();
    }

    public List<T> findRange(int[] range) {
        CriteriaQuery<T> cq = getEm().getCriteriaBuilder().createQuery(getEntityClass());
        cq.select(cq.from(getEntityClass()));
        TypedQuery<T> q = getEm().createQuery(cq);
        q.setMaxResults(range[1] - range[0]);
        q.setFirstResult(range[0]);
        return q.getResultList();
    }

    public long count() {
        CriteriaQuery<Long> cq = getEm().getCriteriaBuilder().createQuery(Long.class);
        Root<T> rt = cq.from(getEntityClass());
        cq.select(getEm().getCriteriaBuilder().count(rt));
        TypedQuery<Long> q = getEm().createQuery(cq);
        return q.getSingleResult();
    }

    protected static <K> K getSingleNullableResult(TypedQuery<K> q) {
        K ret = null;
        try {
            ret = q.getSingleResult();
        } catch (NoResultException e) {
            ret = null;
        }
        return ret;
    }

    public void evict(T entity) {
        if (entity != null && entity.getId() != null) {
            getEm().getEntityManagerFactory().getCache().evict(getEntityClass(), entity.getId());
        }
    }

    protected List<T> search(String query, String[] fields, String orderfield) {
        CriteriaBuilder cb = getEm().getCriteriaBuilder();
        CriteriaQuery<T> cq = cb.createQuery(getEntityClass());
        Root<T> root = cq.from(getEntityClass());
        List<Predicate> preds = new ArrayList<Predicate>();
        for (String field : fields) {
            Path<String> rootfield = root.get(field);
            preds.add(cb.like(rootfield, query));
        }
        cq.where(cb.or(preds.toArray(new Predicate[preds.size()])));
        if (orderfield != null) {
            cq.orderBy(cb.asc(root.get(orderfield)));
        }

        cq.select(root);
        TypedQuery<T> q = getEm().createQuery(cq);
        logger.debug("Creating search query from fields {} query: {}", fields, cq);
        List<T> ret = q.getResultList();
        logger.debug("resultlist size {}", ret.size());
        return ret;
    }
    //
    // @SuppressWarnings("unchecked")
    // public List<T> search(String query, String[] fields) {
    // CompassSession sess =
    // EclipseLinkHelper.getCurrentCompassSession(getEm());
    // CompassQueryBuilder qb = sess.queryBuilder();
    // CompassMultiPropertyQueryStringBuilder properties =
    // qb.multiPropertyQueryString(query);
    //
    // for (String field : fields) {
    // properties.add(field);
    // }
    // String alias = getClass().getSimpleName().toLowerCase();
    //
    // logger.debug("searching class {}", alias);
    // CompassHits hits =
    // qb.bool().addMust(qb.alias(alias)).addMust(properties.toQuery()).toQuery().hits();
    //
    // Iterator<CompassHit> iter = hits.iterator();
    // ArrayList<T> ret = new ArrayList<T>();
    // while (iter.hasNext()) {
    //
    // Object data = iter.next().getData();
    // logger.debug("Found user {}", data);
    // ret.add((T) data);
    //
    // }
    // return ret;
    //
    // }
}