Spring mongo 聚合函数

TypedAggregation<DemoEntity> aggregation = newAggregation(DemoEntity.class, match(match),
                group("name").count().as("total"), sort(Sort.Direction.ASC, "total"), skip(0), limit(3));
        AggregationResults<DBObject> result = mongo.aggregate(aggregation, DBObject.class);
        DBObject obj = result.getRawResults();