I have an ArrayList and want sort it in descending order. I use for it java.util.stream.Stream.sorted(Comparator)
method. Here is a description according Java API:
Returns a stream consisting of the elements of this stream, sorted according to the provided
Comparator
.
this methods return me a sort with ascending order. Which parameter should I change, just to have the descending order?
You can use Comparator.reverseOrder()
to have a comparator giving the reverse of the natural ordering.
If you want to reverse the ordering of an existing comparator, you can use Comparator.reversed()
.
Sample code:
Stream.of(1, 4, 2, 5)
.sorted(Comparator.reverseOrder());
// stream is now [5, 4, 2, 1]
Stream.of("foo", "test", "a")
.sorted(Comparator.comparingInt(String::length).reversed());
// stream is now [test, foo, a], sorted by descending length