list对象排序java_Java:List集合内的对象进行排序

今天药忘吃喽~ 2022-11-05 00:55 263阅读 0赞

List集合中的对象进行排序，除了for外，还有java的Collections对象来对摸个集合进行排序的用法。

比如说我有一个List集合，集合元素为：

public classTaskAutoExecutePlan\{private String id = null;privateAutoExecutePlanType autoExecutePlanType;privateTaskStatus taskStatus;privateString parameters;privateDate createDate;privateDate completeDate;privateDate modifyDate;/\*\*get set 方法\*/\}public enumAutoExecutePlanType \{

ImportSiteCellParameter(2),

WIFI(32);/\*构造函数等\*/\}

如果我需要先按照AutoExecutePlanType进行升序排序，在对CreateDate进行升序排序，使用Collections.sort()该怎么实现呢？

1 public static voidmain(String\[\] args) \{2 SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS");3 Date now = newDate();4 List items = new ArrayList<>();5

6 try\{7 Thread.sleep(10000);8 \} catch(InterruptedException e) \{9 e.printStackTrace();10 \}11

12 TaskAutoExecutePlan plan = newTaskAutoExecutePlan();13 plan.setId(UUID.randomUUID().toString());14 plan.setCreateDate(newDate());15 plan.setAutoExecutePlanType(AutoExecutePlanType.ImportSiteCellParameter);16 items.add(plan);17

19 plan = newTaskAutoExecutePlan();20 plan.setId(UUID.randomUUID().toString());21 plan.setCreateDate(now);22 plan.setAutoExecutePlanType(AutoExecutePlanType.ImportSiteCellParameter);23 items.add(plan);24

25 plan = newTaskAutoExecutePlan();26 plan.setId(UUID.randomUUID().toString());27 plan.setCreateDate(now);28 plan.setAutoExecutePlanType(AutoExecutePlanType.WIFI);29 items.add(plan);30

31 plan = newTaskAutoExecutePlan();32 plan.setId(UUID.randomUUID().toString());33 plan.setCreateDate(newDate());34 plan.setAutoExecutePlanType(AutoExecutePlanType.WIFI);35 items.add(plan);36

37 System.out.println("before sort:");38 for(TaskAutoExecutePlan item : items) \{39 System.out.println(item.getId() + ":" + item.getAutoExecutePlanType() + ":" +format.format(item.getCreateDate()));40 \}41

42 Collections.sort(items, new Comparator() \{43 @Override44 public intcompare(TaskAutoExecutePlan o1, TaskAutoExecutePlan o2) \{45 int i = o1.getAutoExecutePlanType().getValue() -o2.getAutoExecutePlanType().getValue();46 if (i == 0) \{47 if(o1.getCreateDate().equals(o2.getCreateDate())) \{48 return 0;49 \} else if(o1.getCreateDate().after(o2.getCreateDate())) \{50 return 1;51 \} else\{52 return -1;53 \}54 \}55 returni;56 \}57 \});58

59 System.out.println("after sort:");60 for(TaskAutoExecutePlan item : items) \{61 System.out.println(item.getId() + ":" + item.getAutoExecutePlanType() + ":" +format.format(item.getCreateDate()));62 \}63 \}

输出结果：

before sort:

252409be-1bb2-4502-8796-167b43d8de92:ImportSiteCellParameter:2017-02-27 19:36:11.000320

fd7dc92b-b0f4-423a-8644-d95ea0bc6cab:ImportSiteCellParameter:2017-02-27 19:36:00.000294

42bc8d28-90c4-4563-83a3-215c38bc0f9e:WIFI:2017-02-27 19:36:00.000294

d25d4201-f776-4b5f-bf33-8b1f8b80c412:WIFI:2017-02-27 19:36:11.000327

after sort:

fd7dc92b-b0f4-423a-8644-d95ea0bc6cab:ImportSiteCellParameter:2017-02-27 19:36:00.000294

252409be-1bb2-4502-8796-167b43d8de92:ImportSiteCellParameter:2017-02-27 19:36:11.000320

42bc8d28-90c4-4563-83a3-215c38bc0f9e:WIFI:2017-02-27 19:36:00.000294

d25d4201-f776-4b5f-bf33-8b1f8b80c412:WIFI:2017-02-27 19:36:11.000327