Java:List集合内的对象进行排序

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？

public static void main(String[] args) {
    SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS");
    Date now = new Date();
    List<TaskAutoExecutePlan> items = new ArrayList<>();

    try {
        Thread.sleep(10000);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }

    TaskAutoExecutePlan plan = new TaskAutoExecutePlan();
    plan.setId(UUID.randomUUID().toString());
    plan.setCreateDate(new Date());
    plan.setAutoExecutePlanType(AutoExecutePlanType.ImportSiteCellParameter);
    items.add(plan);


    plan = new TaskAutoExecutePlan();
    plan.setId(UUID.randomUUID().toString());
    plan.setCreateDate(now);
    plan.setAutoExecutePlanType(AutoExecutePlanType.ImportSiteCellParameter);
    items.add(plan);

    plan = new TaskAutoExecutePlan();
    plan.setId(UUID.randomUUID().toString());
    plan.setCreateDate(now);
    plan.setAutoExecutePlanType(AutoExecutePlanType.WIFI);
    items.add(plan);

    plan = new TaskAutoExecutePlan();
    plan.setId(UUID.randomUUID().toString());
    plan.setCreateDate(new Date());
    plan.setAutoExecutePlanType(AutoExecutePlanType.WIFI);
    items.add(plan);

    System.out.println("before sort:");
    for (TaskAutoExecutePlan item : items) {
        System.out.println(item.getId() + ":" + item.getAutoExecutePlanType() + ":" + format.format(item.getCreateDate()));
    }

    Collections.sort(items, new Comparator<TaskAutoExecutePlan>() {
        @Override
        public int compare(TaskAutoExecutePlan o1, TaskAutoExecutePlan o2) {
            int i = o1.getAutoExecutePlanType().getValue() - o2.getAutoExecutePlanType().getValue();
            if (i == 0) {
                if (o1.getCreateDate().equals(o2.getCreateDate())) {
                    return 0;
                } else if (o1.getCreateDate().after(o2.getCreateDate())) {
                    return 1;
                } else {
                    return -1;
                }
            }
            return i;
        }
    });

    System.out.println("after sort:");
    for (TaskAutoExecutePlan item : items) {
        System.out.println(item.getId() + ":" + item.getAutoExecutePlanType() + ":" + format.format(item.getCreateDate()));
    }
}

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