Lambda表达式自定义排序，升序再降序

在对list排序的时候可能会碰到两个数据维度的自定义排序

比如一组学生数据&＃xff0c;有考试状态&＃xff0c;要按照考试状态为未考试&＃xff08;考试状态 0 未考试 1 已通过 2 未通过&＃xff09;的排在前面&＃xff0c;其他的状态按照考试时间降序排列。

实体类

&＃64;Data
&＃64;AllArgsConstructor
public class Student {private Integer id;private String name;/*** 考试状态 0 未考试 1 已通过 2 未通过*/private Integer status;/*** 考试时间*/&＃64;JSONField(format &＃61; "YYYY-mm-dd HH:mm:ss")private LocalDateTime timeOfTest;}


排序代码

public static void main(String[] args) {List list &＃61; new ArrayList();list.add(new Student(2, "Sherry", 1, LocalDateTime.parse("2022-05-19T12:34:56")));list.add(new Student(3, "Tom", 0,LocalDateTime.parse("2022-05-19T11:55:56")));list.add(new Student(1, "Tom", 2, LocalDateTime.parse("2022-05-19T15:34:56")));list.add(new Student(5, "Lily", 1, LocalDateTime.parse("2022-05-19T16:11:56")));list.add(new Student(4, "Alisa", 1,LocalDateTime.parse("2022-05-19T22:00:56")));List students&＃61;list.stream().sorted((p1,p2) ->{//如果状态等于0&＃xff08;未考试&＃xff09;&＃xff0c;按照考试状态升序排if (p1.getStatus().equals(0) || p2.getStatus().equals(0)){return p1.getStatus()-p2.getStatus();}else {return p2.getTimeOfTest().compareTo(p1.getTimeOfTest());}}).collect(Collectors.toList());System.out.println(JSON.toJSONString(students));}

输出结果

[{"id":3,"name":"Tom","status":0,"timeOfTest":"2022-05-19T11:55:56"},{"id":4,"name":"Alisa","status":1,"timeOfTest":"2022-05-19T22:00:56"},{"id":5,"name":"Lily","status":1,"timeOfTest":"2022-05-19T16:11:56"},{"id":1,"name":"Tom","status":2,"timeOfTest":"2022-05-19T15:34:56"},{"id":2,"name":"Sherry","status":1,"timeOfTest":"2022-05-19T12:34:56"}
]