Example usage for org.hibernate.internal CriteriaImpl iterateOrderings

Introduction

In this page you can find the example usage for org.hibernate.internal CriteriaImpl iterateOrderings.

Prototype

public Iterator<OrderEntry> iterateOrderings() 

Source Link

Usage

From source file:com.monits.commons.dao.GenericHibernateDao.java

License:Apache License

@SuppressWarnings("unchecked")
protected PaginatedResult<E> getPaginated(final Criteria criteria, final int page, final int amount)
        throws HibernateException, CloneNotSupportedException {

    Preconditions.checkArgument(page >= 0, "Invalid page " + page);
    Preconditions.checkArgument(amount > 0, "Invalid amount " + amount);

    final Session session = sessionFactory.getCurrentSession();

    final CloneableCriteria cc = new CloneableCriteria((CriteriaImpl) criteria);
    final CriteriaImpl clone = (CriteriaImpl) cc.clone().getExecutableCriteria(session);

    final Iterator<?> iterator = clone.iterateOrderings();
    while (iterator.hasNext()) {
        iterator.next();/*from  w  w w.j  a va  2  s  .  c om*/
        iterator.remove();
    }

    final long totalElements = getCount(clone);
    int pageNumber = page;
    if (pageNumber * amount >= totalElements) {
        pageNumber = (int) Math.ceil(totalElements / (double) amount) - 1;
    }

    criteria.setFirstResult(pageNumber * amount).setMaxResults(amount);

    return new PaginatedResult<E>(pageNumber + 1, criteria.list(), totalElements, amount);
}

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From source file:org.candlepin.model.DetachedCandlepinQuery.java

License:Open Source License

/**
 * {@inheritDoc}/*from w  w w.  j  av a2  s  .  c om*/
 */
@Override
@SuppressWarnings({ "unchecked", "checkstyle:indentation" })
public int getRowCount() {
    CriteriaImpl executable = (CriteriaImpl) this.getExecutableCriteria();

    // Impl note:
    // We're using the projection method here over using a cursor to scroll the results due to
    // limitations on various connectors' cursor implementations. Some don't properly support
    // fast-forwarding/jumping (Oracle) and others fake the whole thing by running the query
    // and pretending to scroll (MySQL). Until these are addressed, the hack below is going to
    // be far more performant and significantly safer (which makes me sad).

    // Remove any ordering that may be applied (since we almost certainly won't have the field
    // available anymore)
    for (Iterator iterator = executable.iterateOrderings(); iterator.hasNext();) {
        iterator.next();
        iterator.remove();
    }

    Projection projection = executable.getProjection();
    if (projection != null && projection.isGrouped()) {
        // We have a projection that alters the grouping of the query. We need to rebuild the
        // projection such that it gets our row count and properly applies the group by
        // statement.
        // The logic for this block is largely derived from this Stack Overflow posting:
        // http://stackoverflow.com/
        //     questions/32498229/hibernate-row-count-on-criteria-with-already-set-projection
        //
        // A safer alternative may be to generate a query that uses the given criteria as a
        // subquery (SELECT count(*) FROM (<criteria SQL>)), but is probably less performant
        // than this hack.
        CriteriaQueryTranslator translator = new CriteriaQueryTranslator(
                (SessionFactoryImplementor) this.session.getSessionFactory(), executable,
                executable.getEntityOrClassName(), CriteriaQueryTranslator.ROOT_SQL_ALIAS);

        executable.setProjection(
                Projections.projectionList().add(Projections.rowCount()).add(Projections.sqlGroupProjection(
                        "count(count(1))", translator.getGroupBy(), new String[] {}, new Type[] {})));
    } else {
        executable.setProjection(Projections.rowCount());
    }

    Long count = (Long) executable.uniqueResult();
    return count != null ? count.intValue() : 0;
}

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