一、创建MyRepository接口

在MyRepository中引用MongoTemplate

public interface MyRepository {
    Page<Reading> findTest(SUser sUser, Pageable pageable);
}

二、创建实现类MyRepositoryImpl实现MyRepository

包含Aggregate用法

public class MyRepositoryImpl implements MyRepository {

    @Autowired
    private MongoTemplate mongoTemplate;

    @Override
    public Page<Reading> findTest(SUser sUser, Pageable pageable) {
        ObjectId objectId = new ObjectId(sUser.getId());

        Aggregation aggregation = Aggregation.newAggregation(
            aoc ->
                new Document(
                    "$addFields",
                    new Document("user", new Document("$arrayElemAt", Arrays.asList(new Document("$objectToArray", "$user"), 1L)))
                ),
            aoc -> new Document("$addFields", new Document("user", "$user.v")),
            Aggregation.match(Criteria.where("user").is(objectId)),
            aoc ->
                new Document(
                    "$addFields",
                    new Document("reading", new Document("$arrayElemAt", Arrays.asList(new Document("$objectToArray", "$reading"), 1L)))
                ),
            aoc -> new Document("$addFields", new Document("reading", "$reading.v")),
            Aggregation.lookup("reading", "reading", "_id", "reading"),
            aoc -> new Document("$replaceRoot", new Document("newRoot", new Document("$first", "$reading"))),
            Aggregation.project(
                "id",
                "title",
                "author",
                "genre",
                "alignment",
                "text_summary",
                "clicks",
                "language",
                "is_private",
                "length",
                "date_created",
                "last_updated",
                "uploader",
                "tags",
                "playlists"
            ),
            Aggregation.sort(pageable.getSort()),
            Aggregation.skip(pageable.getPageNumber() * pageable.getPageSize()),
            Aggregation.limit(pageable.getPageSize())
        );

        Aggregation aggregationCount = Aggregation.newAggregation(
            aoc ->
                new Document(
                    "$addFields",
                    new Document("user", new Document("$arrayElemAt", Arrays.asList(new Document("$objectToArray", "$user"), 1L)))
                ),
            aoc -> new Document("$addFields", new Document("user", "$user.v")),
            Aggregation.match(Criteria.where("user").is(objectId)),
            Aggregation.group().count().as("count")
        );

        AggregationResults<Reading> readings = mongoTemplate.aggregate(aggregation, "favorite", Reading.class);
        int count = mongoTemplate.aggregate(aggregationCount, "favorite", ResultCount.class).getMappedResults().get(0).count;

        List<Reading> mappedResults = readings.getMappedResults();
        Page<Reading> page = new PageImpl<>(mappedResults, pageable, count);

        return page;
    }

    class ResultCount {

        int count;
    }
}