在java中有没有合并两个迭代器/数组的好方法？

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

public class IteratorMergeExample {
    public static void main(String[] args) {
        List<Integer> list1 = new ArrayList<>();
        list1.add(1);
        list1.add(2);
        list1.add(3);

        List<Integer> list2 = new ArrayList<>();
        list2.add(4);
        list2.add(5);
        list2.add(6);

        List<Integer> mergedList = new ArrayList<>();
        mergedList.addAll(list1);
        mergedList.addAll(list2);

        Iterator<Integer> iterator = mergedList.iterator();
        while (iterator.hasNext()) {
            System.out.println(iterator.next());
        }
    }
}

import java.util.Arrays;

public class ArrayMergeExample {
    public static void main(String[] args) {
        int[] array1 = {1, 2, 3};
        int[] array2 = {4, 5, 6};

        int[] mergedArray = new int[array1.length + array2.length];
        System.arraycopy(array1, 0, mergedArray, 0, array1.length);
        System.arraycopy(array2, 0, mergedArray, array1.length, array2.length);

        System.out.println(Arrays.toString(mergedArray));
    }
}