在java中有两个比较的空安全比较器

List<String> list = Arrays.asList("apple", null, "banana", "cherry");
list.sort(Comparator.nullsFirst(Comparator.naturalOrder()));
System.out.println(list); // 输出：[null, apple, banana, cherry]

List<String> list = Arrays.asList("apple", null, "banana", "cherry");
list.sort(Comparator.nullsLast(Comparator.naturalOrder()));
System.out.println(list); // 输出：[apple, banana, cherry, null]