从多维数组创建集合？

import java.util.ArrayList;
import java.util.List;

public class Main {
    public static void main(String[] args) {
        int[][] multiArray = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};

        List<Integer> collection = new ArrayList<>();

        for (int[] array : multiArray) {
            for (int element : array) {
                collection.add(element);
            }
        }

        System.out.println(collection);
    }
}