mongo java group操作

DBCollection table = getCollection();// 根据name分组,条件sex="1"BasicDBObject key = new BasicDBObject("name", true);  // 表中的字段BasicDBObject cond = <span style="font-family: Arial, Helvetica, sans-serif;">new BasicDBObject("sex", "1"); </span>BasicDBObject initial = new BasicDBObject();  initial.append("count", 0);  String reduce = "function Reduce(doc, out) { " +          "    out.count +=1;"+            "}";  String fn = "function Finalize(out) {return out;}";  final  BasicDBList  group = (BasicDBList) table.group(key, cond, initial, reduce, fn); int count= 0;for(Object obj:group){JSONObject j = JSONObject.fromObject(obj);                String name = j.getString("name");                        int count = j.getInt("count");}