/**
* Creates a criteria API {@link javax.persistence.criteria.Order} from the given {@link Order}.
*
* @param order the order to transform into a JPA {@link javax.persistence.criteria.Order}
* @param root the {@link Root} the {@link Order} expression is based on
* @param cb the {@link CriteriaBuilder} to build the {@link javax.persistence.criteria.Order}
* with
* @return
*/
@SuppressWarnings("unchecked")
private static javax.persistence.criteria.Order toJpaOrder(
Order order, Root<?> root, CriteriaBuilder cb) {
PropertyPath property = PropertyPath.from(order.getProperty(), root.getJavaType());
Expression<?> expression = toExpressionRecursively(root, property);
if (order.isIgnoreCase() && String.class.equals(expression.getJavaType())) {
Expression<String> lower = cb.lower((Expression<String>) expression);
return order.isAscending() ? cb.asc(lower) : cb.desc(lower);
} else {
return order.isAscending() ? cb.asc(expression) : cb.desc(expression);
}
}
/**
* Returns the order clause for the given {@link Order}. Will prefix the clause with the given
* alias if the referenced property refers to a join alias.
*
* @param joinAliases the join aliases of the original query.
* @param alias the alias for the root entity.
* @param order the order object to build the clause for.
* @return
*/
private static String getOrderClause(Set<String> joinAliases, String alias, Order order) {
String property = order.getProperty();
boolean qualifyReference = !property.contains("("); // ( indicates a function
for (String joinAlias : joinAliases) {
if (property.startsWith(joinAlias)) {
qualifyReference = false;
break;
}
}
String reference = qualifyReference ? String.format("%s.%s", alias, property) : property;
String wrapped = order.isIgnoreCase() ? String.format("lower(%s)", reference) : reference;
return String.format("%s %s", wrapped, toJpaDirection(order));
}
