无法在Springboot中使用Hibernate将MongoDB设置为自动递增

@Entity
public class MyEntity {
    @Id
    private Long id;

    // other fields and getters/setters
}

@Repository
public class MyEntityRepository {
    @Autowired
    private MongoTemplate mongoTemplate;

    public MyEntity save(MyEntity entity) {
        if (entity.getId() == null) {
            entity.setId(getNextSequence("my_entity"));
        }
        return mongoTemplate.save(entity);
    }

    private Long getNextSequence(String collectionName) {
        Query query = new Query(Criteria.where("_id").is(collectionName));
        Update update = new Update().inc("seq", 1);
        FindAndModifyOptions options = new FindAndModifyOptions().returnNew(true).upsert(true);
        Sequence sequence = mongoTemplate.findAndModify(query, update, options, Sequence.class);
        return sequence.getSeq();
    }
}

public class Sequence {
    @Id
    private String id;
    private Long seq;

    // getters/setters
}