+ * Conversion method are: + *
Convertor as merge of provided convertors. Merged convertor will use
+ * provided convertors to convert between currencies.
+ *
+ * Only one should be able to provide conversion between currencies. If more than one convertos
+ * are able to convert currency, one of conversions will be used (it is not defined which).
+ *
+ * @since version 2
+ * @param convertors Convertor used to create merge-convertor.
+ * @return Returns new convertor instance.
+ */
+ public static Convertor createConvertorAsMerge(Convertor[] convertors) {
+ return new Convertor(convertors);
+ }
+
+ boolean remainderAllowed = true; //if false, remained is not allowed (should be true ideally, but can't handle it now)
+ ExchangeRateProvider exchangeRateProvider;
+
+ /** Create simle convertor.
+ */
+ private Convertor() {
+ this.convertors=new Convertor[0];
+ }
+
+ /** Create merge convertor.
+ */
+ private Convertor(Convertor[] convertors) {
+ this.convertors = convertors;
+ }
+
+ /**
+ * Create new
+ * Exchange rate is provided by exchange rate provider which was specified when Convertor was created.
+ * This method is using only exchange rate from->to and not trying to use reverted excange rate to->from.
+ *
+ * @param fromCurrency Source currency to convert from.
+ * @param toCurrency Target currency to convert to.
+ * @param value Value in source currency which should be converted.
+ * @return Return conversion result.
+ * @since version2
+ * @throws ConversionNotSupportedException If conversion from
+ * This method is using only exchange rate from->to and if not found, it is trying to use reverted excange rate to->from.
+ *
+ * @param fromCurrency Source currency to convert from.
+ * @param toCurrency Target currency to convert to.
+ * @param value Value in source currency which should be converted.
+ * @return Return conversion result.
+ * @since version2
+ * @throws ConversionNotSupportedException If conversion from Convertor using ExchangeRateProvider.
+ *
+ * @param exchangeRateProvider {@link ExchangeRateProvider} used to get exchange rate.
+ *
+ * @return Returns Convertor which can be used to convert money.
+ * @since version1
+ */
+ public static Convertor createConvertor(ExchangeRateProvider exchangeRateProvider) {
+ Convertor c = new Convertor();
+
+ c.exchangeRateProvider = exchangeRateProvider;
+ return c;
+ }
+
+ /**
+ * Convert amount from fromCurrency to toCurrency as specified
+ * in ExchangeRateProvider.
+ *
+ * @param amount Amount which should be converted. Can't be negative value (can be zero or positive).
+ * @return Return ConversionResult which holds conversion result.
+ * @since version1
+ * @deprecated since version2. Use {@link #convert(ConvertorCurrency, ConvertorCurrency, BigDecimal) } - explicitly specify conversion currencies.
+ */
+ public ConversionResult convert(BigDecimal amount) {
+ return convertValue(exchangeRateProvider.getFromCurrency(), exchangeRateProvider.getToCurrency(),amount, false,false);
+ }
+
+ /**
+ * Convert amount from toCurrency to fromCurrency as specified
+ * in ExchangeRateProvider. This is reverted order than suggested by names of currency fields in ExchangeRate.
+ *
+ * @param amount Amount which should be converted. Can't be negative value (can be zero or positive).
+ * @return Return ConversionResult which holds conversion result.
+ * @since version1
+ * @deprecated since version2. Use {@link #convert(ConvertorCurrency, ConvertorCurrency, BigDecimal) } - explicitly specify conversion currencies.
+ */
+ public ConversionResult convertBack(BigDecimal amount) {
+ return convertValue(exchangeRateProvider.getFromCurrency(), exchangeRateProvider.getToCurrency(),amount, true,false);
+ }
+
+ private ConversionResult convertUsingSimpleConvertor(ConvertorCurrency fromCurrency, ConvertorCurrency toCurrency, boolean reversibleExRate, BigDecimal amount, boolean convertBack) throws ConversionNotSupportedException, RuntimeException {
+ ConversionResult result = new ConversionResult();
+
+ //ExchangeRate rate = exchangeRateProvider.getExchangeRate();
+ ExchangeRate rate;
+ if (reversibleExRate) {
+ rate = exchangeRateProvider.getReversibleExchangeRate(fromCurrency, toCurrency);
+ } else {
+ rate = exchangeRateProvider.getExchangeRate(fromCurrency, toCurrency);
+ }
+ if (rate == null) {
+ return null;
+ }
+
+ int fromFranctionDigits = fromCurrency.getDefaultFractionDigits();
+ int toFractionDigits = toCurrency.getDefaultFractionDigits();
+
+ if (toFractionDigits != 2) {
+ throw new ConvertorException("Can't process currency with defaultFractionDigits!=2, " + exchangeRateProvider.getToCurrency() + " has " + toFractionDigits + " defaultFractionDigits");
+ }
+ if (fromFranctionDigits != 2) {
+ throw new ConvertorException("Can't process currency with defaultFractionDigits!=2, " + exchangeRateProvider.getFromCurrency() + " has " + fromFranctionDigits + " defaultFractionDigits");
+ }
+
+ if (amount.signum() == -1) {
+ throw new RuntimeException("Can convert only non-negative value, current value is " + amount);
+ }
+
+
+ MathContext context = new MathContext(0, RoundingMode.DOWN);
+
+ BigDecimal from;
+ BigDecimal to;
+ if (convertBack) {
+ //converting in reverted way
+ to = rate.getFromValue();
+ from = rate.getToValue();
+ } else {
+ //converting in normal way
+ from = rate.getFromValue();
+ to = rate.getToValue();
+ }
+
+ BigDecimal amountCent = amount.movePointRight(toFractionDigits);
+
+ final BigDecimal multiplied = amountCent.multiply(to, context);
+ BigDecimal[] division = multiplied.divideAndRemainder(from, context);
+
+ if (!remainderAllowed && !(BigDecimal.ZERO.equals(division[1]))) {
+ throw new RuntimeException("Remained is not allowed - remaining amount is " + division[1] + " cents");
+ } else {
+ result.setRemainder(BigDecimal.ZERO);
+ }
+
+ BigDecimal converted = division[0].movePointLeft(toFractionDigits);
+ converted = converted.setScale(toFractionDigits); //XXX ugly
+ result.setConverted(converted);
+ //result.setRemainder(...);
+ return result;
+ }
+
+
+ private ConversionResult convertValue(ConvertorCurrency fromCurrency, ConvertorCurrency toCurrency,BigDecimal amount, boolean convertBack,boolean reversibleExRate) throws RuntimeException {
+ //result.setRemainder(...);
+ if (convertors.length==0) {
+ return convertUsingSimpleConvertor(fromCurrency, toCurrency, reversibleExRate, amount, convertBack);
+ } else {
+ ConversionResult result = null;
+ for (int i = 0;ifromCurrency to toCurrency.
+ * fromCurrency to toCurrency is not supported.
+ */
+ public ConversionResult convert(ConvertorCurrency fromCurrency, ConvertorCurrency toCurrency, BigDecimal value) {
+ ConversionResult result = convertValue(fromCurrency, toCurrency, value, false,false);
+ if (result==null) {
+ //throw new ConversionNotSupportedException("Conversion from " + fromCurrency + " to " + toCurrency + " is not supported");
+ throw new ConversionNotSupportedException(fromCurrency.getCurrencyCode(),toCurrency.getCurrencyCode(),false);
+ }
+ return result;
+ }
+
+ /**
+ * Convert value from fromCurrency to toCurrency.
+ * Exchange rate is provided by exchange rate provider which was specified when Convertor was created.
+ * fromCurrency to toCurrency
+ * is not supported and neither conversion from toCurrency to fromCurrency is not supported.
+ */
+ public ConversionResult convertWithReversibleRates(ConvertorCurrency fromCurrency, ConvertorCurrency toCurrency, BigDecimal value) {
+ ConversionResult result = convertValue(fromCurrency, toCurrency, value, false,true);
+ if (result==null) {
+ //throw new ConversionNotSupportedException("Neither onversion nor reverted conversion from " + fromCurrency + " to " + toCurrency + " is not supported,");
+ throw new ConversionNotSupportedException(fromCurrency.getCurrencyCode(),toCurrency.getCurrencyCode(),true);
+ }
+ return result;
+ }
+
+}