public <T> List<T> findByNamedQuery(SearchParameters sp) {
if (sp == null || !sp.hasNamedQuery()) {
throw new IllegalArgumentException(
"searchParameters must be non null and must have a namedQuery");
}
Query query = entityManager.createNamedQuery(sp.getNamedQuery());
String queryString = getQueryString(query);
// append order by if needed
if (queryString != null && sp.hasOrders()) {
// create the sql restriction clausis
StringBuilder orderClausis = new StringBuilder("order by ");
boolean first = true;
for (OrderBy orderBy : sp.getOrders()) {
if (!first) {
orderClausis.append(", ");
}
orderClausis.append(orderBy.getColumn());
orderClausis.append(orderBy.isOrderDesc() ? " desc" : " asc");
first = false;
}
if (log.isDebugEnabled()) {
log.debug("appending: [" + orderClausis.toString() + "] to " + queryString);
}
query = recreateQuery(query, queryString + " " + orderClausis.toString());
}
// pagination
if (sp.getFirstResult() >= 0) {
query.setFirstResult(sp.getFirstResult());
}
if (sp.getMaxResults() > 0) {
query.setMaxResults(sp.getMaxResults());
}
// named parameters
setQueryParameters(query, sp);
// execute
@SuppressWarnings("unchecked")
List<T> result = (List<T>) query.getResultList();
if (result != null && log.isDebugEnabled()) {
log.debug(sp.getNamedQuery() + " returned a List of size: " + result.size());
}
return result;
}
