money and currency api

1. Money and Currency
API
Pavel Rozenblioum, Jayway
@javatomte

2. Today’s plan
• Why?
• What?
• Code

3. Why do we need it
float beerAtGreenLionInKrona = 54f;
int beerAtGreenLionInÖre = 54_00;
long beerAtGreenLionInÖre = 54_00;
double beerAtGreenLionInKrona = 54;
BigDecimal beerAtGreenLionInKrona = new BigDecimal(“54”);

4. Why do we need it
• Money is important in many applications
• No standard type for money or support for
conversions
• Currently formatting is limited

5. Money and Currency API
• JSR 354
• JEP in the works
• RI Moneta http://javamoney.github.io/
• Main contributors: Anatole Tresch and Werner
Keil

6. Overview of the API
• javax.money - CurrencyUnit,MonetaryAmount,
MonetaryOperator, factory classes,
exceptions…
• javax.money.conversion - CurrencyConversion,
ExchangeRate
• javax.money.format - formatting
• javax.money.spi - service provider interfaces etc

7.
<dependencies>
<dependency>
<groupId>org.javamoney</groupId>
<artifactId>moneta</artifactId>
<version>1.0-RC3</version>
</dependency>
</dependencies>

8. Currency
CurrencyUnit sek = MonetaryCurrencies.getCurrency("SEK");
//SEK

9. Money
MonetaryAmount hundredSek = MonetaryAmounts
.getDefaultAmountFactory()
.setNumber(100.03523452435)
.setCurrency(sek)
.create();
// SEK 100.03523452435

10. Money
Money alsoHundredSek = Money
.of(100.03523452435, sek);
// SEK 100.03523452435

11. FastMoney
FastMoney fastHundredSek = FastMoney
.of(100.03523452435, sek);
// java.lang.ArithmeticException:
100.03523452435 can not be represented by this
class, scale > 5

12. FastMoney
FastMoney fastHundredSek = FastMoney
.of(100.03523, sek);
//SEK 100.03523

13. Money + FastMoney
MonetaryAmount twoHundredSek =
hundredSek.add(fastHundredSek);
// SEK 200.07046452435
// class Money

14. FastMoney + Money
MonetaryAmount twoHundredSek =
fastHundredSek.add(hundredSek);
//java.lang.ArithmeticException: Parameter
exceeds maximal scale: 5

15. FastMoney + Money
Money roundedMoney = Money.of(100.03523, sek);
MonetaryAmount twoHundredSek =
fastHundredSek.add(roundedMoney);
//SEK 200.07046

16. Mixing Currencies
CurrencyUnit dkk = MonetaryCurrencies
.getCurrency("DKK");
Money hundredDKK = Money.of(100, dkk);
hundredSek.add(hundredDKK);
//javax.money.MonetaryException: Currency
mismatch: SEK/DKK

17. Converting Currencies
CurrencyConversion dkkConversion =
MonetaryConversions.getConversion("DKK");
MonetaryAmount hundredSekInDKK =
hundredSek.with(dkkConversion);
//DKK
81.285852598919388135620537993604757933150536

18. Formatting support
String britishHundredSek = MonetaryFormats
.getAmountFormat(Locale.UK)
.format(hundredSek);
//SEK100.04
String swedishHundredSek = MonetaryFormats
.getAmountFormat(new Locale("sv"))
.format(hundredSek);
//SEK 100,04

19. Custom formats
// Creating a custom MonetaryAmountFormat
AmountFormatQuery formatQuery = AmountFormatQueryBuilder
.of(new Locale("sv"))
.set(CurrencyStyle.NAME)
.set(AmountFormatParams.PATTERN, "Money! ##,##.00 ¤")
.set(AmountFormatParams.GROUPING_SIZES, new int[]{4})
.set(AmountFormatParams.GROUPING_GROUPING_SEPARATORS, new char[]{'?'})
.build();
MonetaryAmountFormat customFormat =
MonetaryFormats.getAmountFormat(
formatQuery);
print(customFormat.format(Money.of(1_000_000, sek)));
Money! 100?0000,00 svensk krona

20. Custom Currencies
CurrencyUnitBuilder.of("FOO", "")
.setDefaultFractionDigits(2)
.setNumericCode(1_000_000)
.build(true);
MonetaryCurrencies.getCurrency("FOO")

21. Play around!

22. Thank you!
@javatomte
pavel@rozenblioum.se