List.sort 排序方法使用

list.sort(new Comparator<Map<String,Object>>(){

        @Override
        public int compare(Map<String, Object> o1, Map<String, Object> o2) {
          Date date1 = (Date) o1.get("tradedate");
          Date date2 = (Date) o2.get("tradedate");
          if(date1.getTime()<date2.getTime()) {
            return -1;
          }else {
            return 0;
          }
        }
        
      });