Example usage for org.springframework.data.mongodb.core.aggregation Aggregation newAggregation

Introduction

In this page you can find the example usage for org.springframework.data.mongodb.core.aggregation Aggregation newAggregation.

Prototype

public static Aggregation newAggregation(AggregationOperation... operations) 

Source Link

Document

Creates a new Aggregation from the given AggregationOperation s.

Usage

From source file:com.epam.ta.reportportal.database.dao.ReportPortalRepositoryImpl.java

@Override
public long getPageNumber(String entityId, Filter filterable, Pageable pageable) {
    Class<T> javaType = this.getEntityInformation().getJavaType();
    ImmutableList.Builder<AggregationOperation> pipelineBuilder = ImmutableList.<AggregationOperation>builder()
            .add(new MatchOperation(
                    new Criteria().andOperator(toArray(toCriteriaList(filterable), Criteria.class))) {
                @Override/*from w w w  . j a  va 2s  .  c o m*/
                public DBObject toDBObject(AggregationOperationContext context) {
                    return super.toDBObject(new TypeBasedAggregationOperationContext(javaType,
                            mongoOperations.getConverter().getMappingContext(), queryMapper));
                }
            });

    if (null != pageable.getSort()) {
        pipelineBuilder.add(
                /* sort results as requested */
                sort(pageable.getSort()));
    }

    pipelineBuilder.add(
            /* group items into one field pushing all results into one array */
            group("result").push("$_id").as("array"),
            /* unwind array adding index to each result */
            unwind("array", "ind", false),
            /* find needed item. How we know its index in query result */
            match(where("array").is(ObjectId.isValid(entityId) ? new ObjectId(entityId) : entityId)),
            /* grab index only */
            project("ind"));

    /* find items matching an provided filter */
    Aggregation a = Aggregation.newAggregation(toArray(pipelineBuilder.build(), AggregationOperation.class));

    final AggregationResults<Map> aggregate = mongoOperations.aggregate(a,
            getEntityInformation().getCollectionName(), Map.class);

    if (!aggregate.getUniqueMappedResult().containsKey("ind")) {
        throw new ReportPortalException(ErrorType.INCORRECT_FILTER_PARAMETERS,
                "Unable to calculate page number. Check your input parameters");
    }

    /* result returned as long. Calculate page number */
    return (long) Math.ceil((((Long) aggregate.getUniqueMappedResult().get("ind")).doubleValue() + 1d)
            / (double) pageable.getPageSize());
}

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