java - 在java中不修改原始列表的子列表

Question

下面的代码实际上修改了原始列表x。考虑到对子列表的修改不应修改原始列表，是否有对主列表进行子列表的方法？

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

x.add(1);
x.add(2);
x.add(3);
x.add(4);
x.add(5);

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

y.add(1);
y.add(2);
y.add(3);

final List<Integer> z = x.subList(0, 4);

System.out.println("sublist " + z.toString());

z.removeAll(y);

System.out.println("Main list after removing sublist " + x.toString());

结果:

sublist [1, 2, 3, 4]
Main list after removing sublist [4, 5]

Answer 1

尝试使用List<Integer> z = new ArrayList<>(x.subList(0, 4))

   List<Integer> x = new ArrayList<Integer>();
    x.add(1);
    x.add(2);
    x.add(3);
    x.add(4);
    x.add(5);

    List<Integer> y = new ArrayList<Integer>();
    y.add(1);
    y.add(2);
    y.add(3);

    final List<Integer> z = new ArrayList<>(x.subList(0, 4));

    System.out.println("sublist " + z.toString());

    z.removeAll(y);

    System.out.println("Main list after removing sublist " + x.toString());

输出:

sublist [1, 2, 3, 4]
Main list after removing sublist [1, 2, 3, 4, 5]