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 class TaskAutoExecutePlan{    private String id = null;    private AutoExecutePlanType autoExecutePlanType;    private TaskStatus taskStatus;    private String parameters;    private Date createDate;    private Date completeDate;    private Date modifyDate;    /**get set 方法*/}public enum  AutoExecutePlanType {    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 void main(String[] args) { 2     SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS"); 3     Date now = new Date(); 4     List
     
       items = new ArrayList<>(); 5  6     try { 7         Thread.sleep(10000); 8     } catch (InterruptedException e) { 9         e.printStackTrace();10     }11 12     TaskAutoExecutePlan plan = new TaskAutoExecutePlan();13     plan.setId(UUID.randomUUID().toString());14     plan.setCreateDate(new Date());15     plan.setAutoExecutePlanType(AutoExecutePlanType.ImportSiteCellParameter);16     items.add(plan);17 18 19     plan = new TaskAutoExecutePlan();20     plan.setId(UUID.randomUUID().toString());21     plan.setCreateDate(now);22     plan.setAutoExecutePlanType(AutoExecutePlanType.ImportSiteCellParameter);23     items.add(plan);24 25     plan = new TaskAutoExecutePlan();26     plan.setId(UUID.randomUUID().toString());27     plan.setCreateDate(now);28     plan.setAutoExecutePlanType(AutoExecutePlanType.WIFI);29     items.add(plan);30 31     plan = new TaskAutoExecutePlan();32     plan.setId(UUID.randomUUID().toString());33     plan.setCreateDate(new Date());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 int compare(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             return i;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