按范围日期分组

Question

List<ObjectA> collapsed = list.stream().collect(Collectors.collectingAndThen(
        Collectors.groupingBy(
                ObjectA::getDate,
                Collectors.maxBy(Comparator
                        .comparing(ObjectA::getPriority1)
                        .thenComparing(ObjectA::getPriority2)
                        .thenComparing(ObjectA::getDate)
                        .thenComparing(ObjectA::getId))),
        map -> map.values().stream()
                .filter(Optional::isPresent)
                .map(Optional::get)
                .collect(Collectors.toList())));

Integer daysWindow = 90;

感谢所有人！

Answer 1

您可以在开始时应用过滤器，如下所示，保持其余内容相同。

LocalDate today = LocalDate.now();

list.stream().filter(obj -> !obj.getDate().isAfter(today.plusDays(90)))
    .collect(Collectors.collectingAndThen(....

注意：我假设Objecta::GetDate是java.time.localDate类型。

演示：

import java.time.LocalDate;

public class Main {
    public static void main(String[] args) {
        // Test
        System.out.println(inRange(LocalDate.now()));
        System.out.println(inRange(LocalDate.of(2021, 12, 31)));
        System.out.println(inRange(LocalDate.of(2022, 2, 20)));
    }

    static boolean inRange(LocalDate date) {
        return !date.isAfter(LocalDate.now().plusDays(90));
    }
}

true
false
false