Summarizing Money

A utility that provides some useful statistics for a given stream of monetary values. This results into an object of type MonetarySummaryStatistics. This object contains some statistical information such as the minimum and maximum values, average, sum, and the number of elements in the stream. A currency must be provided and amounts with different currencies will be ignored. Here's an example.

public class AggregateSummaringMonetaryAmount {

    public static void main(String[] args) {
        CurrencyUnit dollar = Monetary.getCurrency("USD");
        CurrencyUnit real = Monetary.getCurrency("BRL");



        MonetaryAmount money = Money.of(10, dollar);
        MonetaryAmount money2 = Money.of(10, real);
        MonetaryAmount money3 = Money.of(10, dollar);
        MonetaryAmount money4 = Money.of(9, real);
        MonetaryAmount money5 = Money.of(25, dollar);

        MonetarySummaryStatistics summary = Stream.of(money, money2, money3, money4, money5)
                .collect(MonetaryFunctions.summarizingMonetary(dollar));

        MonetaryAmount min = summary.getMin();//USD 10
        MonetaryAmount max = summary.getMax();//USD 25
        MonetaryAmount average = summary.getAverage();//USD 15
        long count = summary.getCount();//3
        MonetaryAmount sum = summary.getSum();//USD 45

    }
}

Moneta provides grouping of MonetarySummaryStatistics from the currencies.

public class AggregateGroupSummaringMonetaryAmount {

    public static void main(String[] args) {
        CurrencyUnit dollar = Monetary.getCurrency("USD");
        CurrencyUnit real = Monetary.getCurrency("BRL");



        MonetaryAmount money = Money.of(10, dollar);
        MonetaryAmount money2 = Money.of(10, real);
        MonetaryAmount money3 = Money.of(10, dollar);
        MonetaryAmount money4 = Money.of(9, real);
        MonetaryAmount money5 = Money.of(25, dollar);

        GroupMonetarySummaryStatistics grouped = Stream.of(money, money2, money3, money4, money5)
        .collect(MonetaryFunctions.groupBySummarizingMonetary());
        Map<CurrencyUnit, MonetarySummaryStatistics> mapSummary = grouped.get();
        MonetarySummaryStatistics summary = mapSummary.get(dollar);

        MonetaryAmount min = summary.getMin();//USD 10
        MonetaryAmount max = summary.getMax();//USD 25
        MonetaryAmount average = summary.getAverage();//USD 15
        long count = summary.getCount();//3
        MonetaryAmount sum = summary.getSum();//USD 45

    }
}

Currency conversions can be applied to MonetarySummaryStatisticsif an ExchangeRateProvideris provided.

public class AggregateSummaringExchangeRateMonetaryAmount {

    public static void main(String[] args) {
        CurrencyUnit dollar = Monetary.getCurrency("USD");
        CurrencyUnit real = Monetary.getCurrency("BRL");

        ExchangeRateProvider provider = MonetaryConversions.getExchangeRateProvider(ExchangeRateType.IMF);

        MonetaryAmount money = Money.of(10, dollar);
        MonetaryAmount money2 = Money.of(10, real);
        MonetaryAmount money3 = Money.of(10, dollar);
        MonetaryAmount money4 = Money.of(9, real);
        MonetaryAmount money5 = Money.of(25, dollar);

        MonetarySummaryStatistics summary = Stream.of(money, money2, money3, money4, money5)
                .collect(ConversionOperators.summarizingMonetary(dollar, provider));

        MonetaryAmount min = summary.getMin();//USD 2.831248
        MonetaryAmount max = summary.getMax();//USD 25
        MonetaryAmount average = summary.getAverage();//USD 10.195416
        long count = summary.getCount();//5
        MonetaryAmount sum = summary.getSum();//50.97708

    }
}