对List<Map<String,Obejct>> 类型的数据进行时间排序（降序）- 20180408

Collections.sort(mapList, new Comparator<Map<String, Object>>() {
            @Override
            public int compare(Map<String, Object> o1, Map<String, Object> o2) {
                if (o1.get("stopTime") == null && o2.get("stopTime") == null)
                    return 0;
                if (o1.get("stopTime") == null)
                    return -1;
                if (o2.get("stopTime") == null)
                    return 1;
                return Long.valueOf(JSON.toJSONString(o2.get("stopTime"))).compareTo(Long.valueOf(JSON.toJSONString(o1.get("stopTime"))));
            }
        });

      //sort--下面是根据list的map中的一个时间字段排序的例子
        //List<Map<String, Object>> resultList = new ArrayList<Map<String, Object>>();
        Collections.sort(resultList, new Comparator<Map<String, Object>>() {

            public int compare(Map<String, Object> o1, Map<String, Object> o2) {
                SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                String s1 = o1.get("S_DATE").toString();
                String s2 = o2.get("S_DATE").toString();
                long val1 = 0;
                long val2 = 0;
                try {
                    val1 = format.parse(s1).getTime();
                    val2 = format.parse(s2).getTime();
                } catch (ParseException e) {

                }
                return (int) (val2 - val1);
            }
        });