Paginação Hibernate

Pagination.java

public class Pagination<T> {

	private final long totalRecords;
	private final List<T> results;

	public Pagination(long totalRecords, List<T> results) {
		this.totalRecords = totalRecords;
		this.results = results;
	}

	public List<T> getResults() {
		return results;
	}

	public long getTotalRecords() {
		return totalRecords;
	}
}

PaginationParams.java

public class PaginationParams {

	private Integer page;
	private Integer rows;
	private String orderBy;

	public PaginationParams() {
	}

	public PaginationParams(Integer page, Integer rows, String orderBy) {
		this.setPage(page);

		this.rows = rows;

		this.orderBy = orderBy;
	}

	public Integer getPage() {
		return (page + 1);
	}

	public Integer getRows() {
		return rows;
	}

	public Integer getFirstResults() {
		return page * rows;
	}

	public String getOrderBy() {
		return orderBy;
	}

	public void setOrderBy(String orderBy) {
		this.orderBy = orderBy;
	}

	public Order getOrderByCriteria() {
		return getOrdersParams().get(0);
	}

	public List<Order> getListOfOrderByCriteria() {
		return getOrdersParams();
	}

	private List<Order> getOrdersParams() {
		String[] params = getOrderBy().split(" ");
		String[] properties = params[0].split(",");
		String order = params[1];

		List<Order> orders = new ArrayList<Order>();
		for (String property : properties) {
			orders.add(order.equalsIgnoreCase("asc") ? Order.asc(property) : Order.desc(property));
		}
		return orders;
	}

	public void setRows(Integer rows) {
		this.rows = rows;
	}

	public void setPage(Integer page) {
		this.page = page <= 0 ? 0 : --page;
	}

}

Paginator.java

public class Paginator<T> {

	private final Query query;
	private final Criteria criteria;

	public Paginator(Query query) {
		this.query = query;
		this.criteria = null;
	}

	public Paginator(Criteria criteria) {
		this.criteria = criteria;
		this.query = null;
	}

	public final Pagination<T> paginate(PaginationParams paginationParams) {
		final long totalRecords = totalRecords();

		List<T> results = generateList(paginationParams);

		return new Pagination<T>(totalRecords, results);
	}

	@SuppressWarnings("unchecked")
	private List<T> generateList(PaginationParams paginationParams) {
		Integer firstResults = paginationParams.getFirstResults();
		Integer rows = paginationParams.getRows();

		return query == null ? criteria.setFirstResult(firstResults).setMaxResults(rows).list() : query.setFirstResult(firstResults)
				.setMaxResults(rows).list();
	}

	private long totalRecords() {
		if (query != null) {
			return query.list().size();
		}
		if (criteria != null) {
			Long count = (Long) criteria.setProjection(Projections.countDistinct("id")).uniqueResult();
			criteria.setProjection(null);
			criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);
			return count;
		}
		return 0;
	}
}