交换集合中指定位置的内容。

private static void test08() {
List<String> list = new ArrayList<>();
Collections.addAll(list, "a", "g", "as");
System.out.println("交换之前的集合：");
Iterator<String> iterator = list.iterator();//获取迭代器
while (iterator.hasNext()) {
System.out.print(iterator.next() + "、");
}
System.out.println("\n" + "交换之后的集合：");
Collections.swap(list, 0, 2);//将集合中索引为0的和索引为2的元素进行交换
Iterator<String> iterator2 = list.iterator();
while (iterator2.hasNext()) {
System.out.print(iterator2.next() + "、");
}
}