I'd like to build a Sort
object using this Optional
-like code:
private Sort buildSort(Collection<String> fields) {
fields.stream()
.map(this::buildOrder)
.collect(Sort.unsorted(), ????, ????);
}
buildOrder
is:
private Order buildOrder(String field) {
if (field.startsWith("-")) {
return Order.desc(field.substring(1));
}
else {
return Order.asc(field);
}
}
I need to return an Sort.unsorted()
if stream is empty, or combine each Sort
object.
Sort object has an and
method that stands for building and concatenate orders.
Sort.by(sort1)
.and(sort2)...
So I need that:
if (stream is empty) then
return Sort.unsorted
else
return foreach item in stream:
Sort.by(item).and(item2).and(item3)...
Classes:
org.springframework.data.domain.Sort
org.springframework.data.domain.Sort.Order
NOTE
I need to use stream-api!