嵌套集合使用迭代器遍历时抛java.util.NoSuchElementException_Be_insighted的博客

public class CollectionNestIterator {
    public static void main(String[] args) {
        Collection<Integer> left = new ArrayList<>(Arrays.asList(1,2,3,4,5));

        Collection<Integer> right = new ArrayList<>(Arrays.asList(1,2,3,4,5,6,7));

        for (Iterator<Integer> l = left.iterator(); l.hasNext();) {
            for (Iterator<Integer> r = right.iterator(); r.hasNext();) {
                System.out.println(l.next() * r.next());
            }
        }

    }
}public class CollectionNestIterator {
    publi