MongoTemplate matching referenced object in aggregation

Question

Using MongoTemplate with Criteria to match a Document against a related User as below:

var query = new Query().with(pageable);
query.addCriteria(Criteria.where("user").is(user));
query.addCriteria(Criteria.where("date").gte(startDate).lt(endDate));

mongoTemplate.find(query, MyClass.class);

results in the correct query being generated by Spring:

{
    "user": {
        "$oid": "621bd3461be5bb603f139353"
    },
    "date": {
        "$gte": {
            "$date": "2021-10-20T00:00:00Z"
        },
        "$lt": {
            "$date": "2021-10-21T00:00:00Z"
        }
    }
}

however, when using the same Criteria using the aggregation framework, in a $match operation as in:

var filterMatch = Aggregation.match(
            new Criteria()
                .andOperator(
                    Criteria.where("user").is(user),
                    Criteria.where("date").gte(startDate).lt(endDate)
                )
        );

the logs show the whole User Document is being used to match:

{
        "$match": {
            "$and": [
                {
                    "user": {
                        "_id": {
                            "$oid": "621bd3461be5bb603f139353"
                        },
                        "login": "xxx",
                        "password": "$2a$10$hqx1bowiYiqP",
                        "email": "xxx",
                        "activated": true,
                        "resetKey": "Yt3cXyRvU7QaM58ggQC0",
                        "createdBy": "anonymousUser",
                        "createdDate": {
                            "$date": "2022-02-27T19:38:46.749Z"
                        },
                        "lastModifiedBy": "anonymousUser",
                        "lastModifiedDate": {
                            "$date": "2022-03-05T13:10:59.761Z"
                        }
                    }
                },
                {
                    "date": {
                        "$gte": {
                            "$date": "2022-02-01T00:00:00Z"
                        },
                        "$lt": {
                            "$date": "2022-02-02T00:00:00Z"
                        }
                    }
                }
            ]
        }
    }

Also, for some reason the latest doesn't work and returns nothing.

This one-to-many relation in the entities is done using @DocumentReference

@DocumentReference
@Indexed
@Field("user")
@JsonIgnore
private User user;

What's one correct way to achieve this with the aggregation framework in Spring Mongo?

Answer 1

For those who find this question in the future...

Using @DocumentReference inserts only the id of the foreign document in the current document, so doing

var filterMatch = Aggregation.match(
            new Criteria()
                .andOperator(
                    Criteria.where("user").is(new ObjectId(userId)),
                    Criteria.where("date").gte(startDate).lt(endDate)
                )
        );

solved my problem.