code: private void cacheFieldRefKey(String fieldCacheKey,String idCacheKey,long expired){
  		if(nullValueCache){
  			getCacheProvider().set(fieldCacheKey, idCacheKey, expired);
  		}else{
  			getCacheProvider().setStr(fieldCacheKey, idCacheKey, expired);
  		}
  	}
docs: 缓存字段查询到idkey
  @param fieldCacheKey
  @param idCacheKey
  @param expired