使用Java 8 Stream API按范围分组

import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

public class Main {
    public static void main(String[] args) {
        List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10);

        Map<String, List<Integer>> groupedNumbers = numbers.stream()
                .collect(Collectors.groupingBy(number -> {
                    if (number <= 5) {
                        return "1-5";
                    } else {
                        return "6-10";
                    }
                }));

        System.out.println(groupedNumbers);
    }
}

{1-5=[1, 2, 3, 4, 5], 6-10=[6, 7, 8, 9, 10]}