分区列表到Java8中的子列表

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

public class PartitionExample {
    public static void main(String[] args) {
        List<Integer> numbers = IntStream.range(0, 20).boxed().collect(Collectors.toList());
        int partitionSize = 5;

        List<List<Integer>> partitions = partition(numbers, partitionSize);

        partitions.forEach(subList -> {
            System.out.println(subList);
        });
    }

    public static <T> List<List<T>> partition(List<T> list, int size) {
        return IntStream.range(0, list.size())
                .boxed()
                .collect(Collectors.groupingBy(index -> index / size))
                .values()
                .stream()
                .map(indices -> indices.stream().map(list::get).collect(Collectors.toList()))
                .collect(Collectors.toList());
    }
}

if (partitionSize <= 0) {
    throw new IllegalArgumentException("Partition size must be greater than 0");
}
if (partitionSize > list.size()) {
    partitionSize = list.size();
}