如何在Spring Mongo聚合中将日期转换为时间戳

Question

我想知道如何将这些mongo单元格查询转换为spring mongo查询

{$addFields:{"creationTime":{$toLong:"$creationTime"}}}

或

{ "$group" : { "_id" : "$id","timestamp" : { "$push" : {$toLong:"$creationTime" }} } }