I have a list ArrayList<Integer> list = new ArrayList<Integer>();
where I have over 40,000 records.
I wonder if you have a way to get only the top 10,000.
I know you have to for and move to a new list, but this requires a lot of processing.
Would it have a simpler way? Or with Lambda?
List<Integer> list = new ArrayList<>();
// Adiciona os 40 mil registros...
List<Integer> list2 = list.stream().limit(10000).collect(Collectors.toList());
Maybe, to avoid wasting processing, you'd prefer to work with Stream s directly, avoiding using collect method . In this case, you would do this:
Stream<Integer> stream = list.stream().limit(10000);
The key is to use limit .
According to the documentation, it has the function:
List<E> subList(int fromIndex, int toIndex)
//Returns a view of the portion of this list between the specified fromIndex, inclusive, and toIndex, exclusive.
Then, in your case:
ArrayList<Integer> array = new ArrayList<Integer>();
....
// Adicionar items ao array
....
List<Integer> array2 = array.subList(0,10000);