List排序

List<Map<String,Object>> list = new ArrayList<Map<String,Object>>(); 

Collections.sort(list, new Comparator<Map<String,Object>>(){                public int compare(Map<String, Object> o1, Map<String, Object> o2)              {               int b1 = (Integer) o1.get("items_sold");             int b2 = (Integer)o2.get("items_sold");               if (b1>b2) {                   return -1;               }else if(b1==b2){               return 0;               }else{               return 1;               }            }                        });  

当List中是个Map，new Comparator时也要加上，否则参数类型不匹配。