+ * Several method can be created to create ExchangeRateProvider:
+ *
+ * Date dependend exchange rate to be implemented.
+ *
+ * @author arnostvalicek
+ */
+public class ExchangeRateProvider {
+
+ IExchangeRateEngine exrateEngine;
+
+ /**
+ * Simple constructor for ExchangeRateProviderM which can provide fixed exchange rate.
+ *
+ * Describes conversion from ONE to to ONE currency.
+ *
+ * @param fromValue From value. BigDecimal value, precision should be set to currency precision.
+ * @param fromCurrency From currency.
+ * @param toValue To value. BigDecimal value, precision should be set to currency precision.
+ * @param toCurrency To currency.
+ * @deprecated deprecated since task2. Use {@link #createExchangeRateProvider() } instead of this constructor.
+ */
+ public ExchangeRateProvider(BigDecimal fromValue, ConvertorCurrency fromCurrency, BigDecimal toValue, ConvertorCurrency toCurrency) {
+ this.exrateEngine = FixedOneExchangeRateEngine.createEngine(fromValue, fromCurrency, toValue, toCurrency);
+ }
+
+ private ExchangeRateProvider() {
+ }
+
+ /**
+ * Static method to create new exchange rate provider. This exchange rate provider does not contain
+ * any exchange rates (this is difference to public constructor).
+ * @return New ExchangeRateProvider
+ */
+ public static ExchangeRateProvider createExchangeRateProvider() {
+ ExchangeRateProvider provider = new ExchangeRateProvider();
+ provider.exrateEngine = FixedExchangeRateEngine.createEngine();
+ return provider;
+ }
+
+ /**
+ * Static method to create exchange rate provider which is using provided IExchangeRateEngine. This exchange rate provider is using
+ * IExchangeRateEngine to get actual exchange rate.
+ * @param exchangeRateEngine IExchangeRateEngine used to get exchange rate.
+ * @return Returns instance of ExchangeRateProvider
+ */
+ public static ExchangeRateProvider createExchangeRateProvider(IExchangeRateEngine exchangeRateEngine) {
+ ExchangeRateProvider provider = new ExchangeRateProvider();
+ provider.exrateEngine = exchangeRateEngine;
+ return provider;
+ }
+
+ /**
+ * Add new exchange rate to to this simple exchange rate provider.
+ *
+ * Example of specifiing conversion rate: 100 SKK == 80 CZK:
+ * addFixedCurencyRate(ConvertorCurrency.getInstance("SKK"), new BigDecimal(100), ConvertorCurrency.getInstance("CZK"), new BigDecimal(80));
+ *
+ * This method may be used only when ExchangeRateProvider is created using {@link #createExchangeRateProvider() } - creating exchange rate provider without external IExchangeRateEngine.
+ *
+ * @param fromCurrency Source currency.
+ * @param fromValue Valye for from currency.
+ * @param toCurrency Target currency.
+ * @param toValue Value for target currency.
+ * @throws IllegalStateException Throws exception when adding fixed currency rate to exchange rate provider which is not created using {@link #createExchangeRateProvider() }.
+ */
+ public synchronized void addFixedCurencyRate(ConvertorCurrency fromCurrency, BigDecimal fromValue, ConvertorCurrency toCurrency, BigDecimal toValue) {
+ if (exrateEngine instanceof FixedExchangeRateEngine) {
+ ((FixedExchangeRateEngine) exrateEngine).addFixedCurencyRate(fromCurrency, fromValue, toCurrency, toValue);
+ } else {
+ throw new IllegalStateException("Cuurency rate can be added only to ExchangeRateProvider created with FixedExchangeRateEngine - using method createExchangeRateProvider()");
+ }
+ }
+
+ /**
+ * Get fixed exange rate for currencies (from->to).
+ * @return Returns exchange rate.
+ * @deprecated deprecated since task2. Use {@link #getExchangeRate(ConvertorCurrency, ConvertorCurrency) }
+ */
+ public ExchangeRate getExchangeRate() {
+ //works only for FixedExchangeRateEngine
+ if (exrateEngine instanceof FixedOneExchangeRateEngine) {
+ FixedOneExchangeRateEngine engine = (FixedOneExchangeRateEngine) exrateEngine;
+ return new ExchangeRate(engine.getFromValue(), engine.getToValue());
+ } else {
+ throw new IllegalStateException("Method supported only for MinimalFixedExchangeRateEngine. This method is deprecated");
+ }
+
+ }
+
+ /**
+ * Get fixed exange rate for currencies (from->to).
+ * @return Returns exchange rate or null if exchange rate not found.
+ */
+ public ExchangeRate getExchangeRate(ConvertorCurrency fromCurrency, ConvertorCurrency toCurrency) {
+ return getExchangeRateImpl(fromCurrency, toCurrency);
+ }
+
+ /**
+ * Get fixed exange rate for currencies (from->to) or reversed exchange rate (to->from).
+ * @return Returns exchange rate or null if exchange rate not found.
+ */
+ public ExchangeRate getReversibleExchangeRate(ConvertorCurrency fromCurrency, ConvertorCurrency toCurrency) {
+ ExchangeRate rate = getExchangeRateImpl(fromCurrency, toCurrency);
+ if (rate == null) {
+ ExchangeRate revertedRate = getExchangeRateImpl(toCurrency, fromCurrency);
+ if (revertedRate != null) {
+ rate = ExchangeRate.createRevertedRate(revertedRate);
+ }
+ }
+ return rate;
+ }
+
+ /**
+ * Get exchange rate for currencies (from->to) based on provided date.
+ * @param date Date for which exchange rate should be provided.
+ * @return Returns exchange rate
+ * @deprecated deprecated since task2. No real implementation in version2.
+ */
+ public ExchangeRate getExchangeRate(Date date) {
+ //works only for FixedExchangeRateEngine
+ if (exrateEngine instanceof FixedOneExchangeRateEngine) {
+ FixedOneExchangeRateEngine engine = (FixedOneExchangeRateEngine) exrateEngine;
+ return new ExchangeRate(engine.getFromValue(), engine.getToValue());
+ } else {
+ throw new IllegalStateException("Method supported only for FixedOneExchangeRateEngine. This method is deprecated");
+ }
+ }
+
+ ConvertorCurrency getFromCurrency() {
+ if (exrateEngine instanceof FixedOneExchangeRateEngine) {
+ FixedOneExchangeRateEngine engine = (FixedOneExchangeRateEngine) exrateEngine;
+ return engine.getFromCurrency();
+ } else {
+ throw new IllegalStateException("Method supported only for FixedOneExchangeRateEngine. This method is deprecated");
+ }
+ }
+
+ ConvertorCurrency getToCurrency() {
+ if (exrateEngine instanceof FixedOneExchangeRateEngine) {
+ FixedOneExchangeRateEngine engine = (FixedOneExchangeRateEngine) exrateEngine;
+ return engine.getToCurrency();
+ } else {
+ throw new IllegalStateException("Method supported only for FixedOneExchangeRateEngine. This method is deprecated");
+ }
+ }
+
+ private ExchangeRate getExchangeRateImpl(ConvertorCurrency fromCurrency, ConvertorCurrency toCurrency) {
+ ExchangeRate result = exrateEngine.getExchangeRate(fromCurrency, toCurrency);
+ return result;
+ }
+
+ private static class FixedOneExchangeRateEngine implements IExchangeRateEngine {
+
+ BigDecimal fromValue;
+ ConvertorCurrency fromCurrency;
+ BigDecimal toValue;
+ ConvertorCurrency toCurrency;
+
+ private FixedOneExchangeRateEngine(BigDecimal fromValue, ConvertorCurrency fromCurrency, BigDecimal toValue, ConvertorCurrency toCurrency) {
+ this.fromValue = fromValue;
+ this.toValue = toValue;
+ this.fromCurrency = fromCurrency;
+ this.toCurrency = toCurrency;
+ }
+
+ /**
+ * Create IExchangeRateEngine conveting from fromCurrency to toCurrency
+ * with echange rate fromValue:toValue
+ * @param fromValue
+ * @param fromCurrency
+ * @param toValue
+ * @param toCurrency
+ * @return Returns instance of FixedOneExchangeRateEngine.
+ */
+ private static IExchangeRateEngine createEngine(BigDecimal fromValue, ConvertorCurrency fromCurrency, BigDecimal toValue, ConvertorCurrency toCurrency) {
+ return new FixedOneExchangeRateEngine(fromValue, fromCurrency, toValue, toCurrency);
+ }
+
+ private BigDecimal getFromValue() {
+ return fromValue;
+ }
+
+ private BigDecimal getToValue() {
+ return toValue;
+ }
+
+ private ConvertorCurrency getFromCurrency() {
+ return fromCurrency;
+ }
+
+ private ConvertorCurrency getToCurrency() {
+ return toCurrency;
+ }
+
+ public ExchangeRate getExchangeRate(ConvertorCurrency fromCurrency, ConvertorCurrency toCurrency) {
+ if (!fromCurrency.equals(this.fromCurrency)) {
+ return null;
+ }
+ if (!toCurrency.equals(this.toCurrency)) {
+ return null;
+ }
+ return new ExchangeRate(fromValue, toValue);
+ }
+ }
+
+ /**
+ * Exchange rate engine able to hold several fixed exchange rates.
+ *
+ * @author arnostvalicek
+ */
+ private static class FixedExchangeRateEngine implements IExchangeRateEngine {
+
+ private Map exchangeRateMap = new HashMap();
+
+ private FixedExchangeRateEngine() {
+ }
+
+ /**
+ * Create instance of FixedExchangeRateEngine.
+ * @return Returns instance of FixedExchangeRateEngine.
+ */
+ public static IExchangeRateEngine createEngine() {
+ return new FixedExchangeRateEngine();
+ }
+
+ public ExchangeRate getExchangeRate(ConvertorCurrency fromCurrency, ConvertorCurrency toCurrency) {
+ Map map2 = (Map) exchangeRateMap.get(fromCurrency);
+ if (map2 == null) {
+ return null;
+ }
+ ExchangeRate result = (ExchangeRate) map2.get(toCurrency);
+ return result;
+ }
+
+ @SuppressWarnings("unchecked")
+ public synchronized void addFixedCurencyRate(ConvertorCurrency fromCurrency, BigDecimal fromValue, ConvertorCurrency toCurrency, BigDecimal toValue) {
+ if (fromValue == null) {
+ throw new NullPointerException("fromValue can't be null");
+ }
+ if (toValue == null) {
+ throw new NullPointerException("toValue can't be null");
+ }
+ Map map2 = (Map) exchangeRateMap.get(fromCurrency);
+ if (map2 == null) {
+ map2 = new HashMap();
+ exchangeRateMap.put(fromCurrency, map2);
+ }
+
+ ExchangeRate rate = new ExchangeRate(fromValue, toValue);
+ map2.put(toCurrency, rate);
+ }
+ }
+}