list中依据map<String,Object>的某个值排序

private void sort(List<Map<String, Object>> list) {
         Collections.sort(list, new Comparator<Map<String, Object>>(){
          public int compare(Map<String, Object> o1, Map<String, Object> o2) {                    
          //依据map中某个字段，从小到大排序
       return  (Integer)o1.get("num")>(Integer)o2.get("num")?1:( (Integer)o1.get("num")==(Integer)o2.get("num")?0:-1);
           } 
          });
    }