java遇到的问题02

Comparator.comparing(keyExtractor,keyComparator) ： 将keyExtractor算出的值，用keyComparator比较

Comparator.nullsLast(比较器) ：比较器比较，null排最后

   @Test
    public void test01 (){
        Student s1 = new Student("Aam", 1);
        Student s2 = new Student("Bhyam", 2);
        Student s3 = new Student("Cohan", 3);

        List<Student> list = Arrays.asList(s1,null, s2, null, s3);
//        Collections.sort(list, Comparator.nullsLast(Comparator.comparing()));
        Comparator<Student> comparing = Comparator.comparing(Student::getName, String.CASE_INSENSITIVE_ORDER);
        Collections.sort(list,Comparator.nullsLast(Comparator.comparing(Student::getName)));
//        Collections.sort(list,Comparator.nullsLast(Comparator.comparing(Student::getName).reversed()));
//        Collections.sort(list,Comparator.nullsLast(Comparator.naturalOrder()));
//        Collections.sort(list,Comparator.nullsLast(null));
        System.out.println(list);
    }
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15