Close Java 8 Stream

Question

If we use Java 8 Stream like list.stream().filter(....).collect(..)..... When is it closed this stream?

Is it good practice that we close the stream us

Answer 1

I have to add that by default streams are not closed at all!

List list = Arrays.asList(1,2,3,4,5,6,7,8,9,10);

// "--" is not printed at all:
list.stream().onClose(()->System.out.println("--")).forEach(x -> System.out.println(x));

System.out.println("with try(){}:");

// "--" is printed:
try (Stream stream = list.stream() ) {
    stream.onClose(() -> System.out.println("--")).forEach(x -> System.out.println(x));
}