你可以将BasicDbObject直接传递到任何聚合管道阶段。
Aggregation agg = newAggregation( group("title"). push(new BasicDBObject ("version", "$version").append ("author", "$author").append
你可以将BasicDbObject直接传递到任何聚合管道阶段。
Aggregation agg = newAggregation( group("title"). push(new BasicDBObject ("version", "$version").append ("author", "$author").append