求对以下list数据进行按时间倒序排列

[程序猿的那点事]

Item item = new Item();
item.name = "jack";
item.date= "2016-11-30 21:20:12";

Item item = new Item();
item.name = "tom";
item.date= "2016-12-30 21:20:12";

Item item = new Item();
item.name = "jack";
item.date= "2016-10-30 21:20:12";

Item item = new Item();
item.name = "jack";
item.date= "2016-12-31 21:20:12";

List<Item> item = new ArrayList<>();
item.add(item);

[寒冰大神]

实现Comparator接口 按时间 进行排序 Collections.sort(item, new Comparator<Item >(){ public int compare(Item arg0, Item arg1) { } }

[程序猿的那点事]

引用 1 楼 qq_34364155 的回复:

实现Comparator接口 按时间 进行排序 Collections.sort(item, new Comparator<Item >(){ public int compare(Item arg0, Item arg1) { } }

public int compare(Item arg0, Item arg1) { }这里面应该怎么写呢

[寒冰大神]

Item item1 = new Item(); item1.name = "jack"; item1.date = "2016-11-30 21:20:12"; Item item2 = new Item(); item2.name = "tom"; item2.date = "2016-12-30 21:20:12"; Item item3 = new Item(); item3.name = "jack"; item3.date = "2016-10-30 21:20:12"; Item item4 = new Item(); item4.name = "jack"; item4.date = "2016-12-31 21:20:12"; List<Item> itemlist = new ArrayList<>(); itemlist.add(item1); itemlist.add(item2); itemlist.add(item3); itemlist.add(item4); Collections.sort(itemlist, new Comparator<Item>() { @Override public int compare(Item item, Item t1) { Date date1 = TimeUtils.string2Date(item.date); Date date2 = TimeUtils.string2Date(t1.date); // 对日期字段进行升序，如果欲降序可采用after方法 if (date1.before(date2)) { return 1; } return -1; } }); for (Item s : itemlist) { Log.e("date", s.date); }

[寒冰大神]

Collections.sort(itemlist, new Comparator<Item>() { @Override public int compare(Item item, Item t1) { SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); Date date1 = null; Date date2 = null; try { date1 = new Date(format.parse(item.date).getTime()); date2 = new Date(format.parse(t1.date).getTime()); }catch (ParseException e){ } // 对日期字段进行升序，如果欲降序可采用after方法 if (date1.before(date2)) { return 1; } return -1; } });