japod@49: 
japod@49: package org.apidesign.apifest08.currency;
japod@49: 
japod@49: public final class CurrencyRateImpl implements CurrencyRate {
japod@49:     private String currency1;
japod@49:     private String currency2;
japod@49:     private Rate rate;
japod@49:     
japod@49:     CurrencyRateImpl(final String currency1, final String currency2, final Rate rate) {
japod@49:         if ((currency1 == null)||(currency2 == null) || (rate == null)) {
japod@49:             throw new IllegalArgumentException("Argument cannot be null.");
japod@49:         }
japod@49:         if ("".equals(currency1) || "".equals(currency2)) {
japod@49:             throw new IllegalArgumentException("Name of currency cannot be empty string");
japod@49:         }
japod@49:         if (currency1.equals(currency2)) {
japod@49:             throw new IllegalArgumentException("Currencies in rate cannot be the same");
japod@49:         }
japod@49:        
japod@49:         this.currency1 = currency1;
japod@49:         this.currency2 = currency2;
japod@49:         this.rate = rate;
japod@49:     }
japod@49: 
japod@49:     public String getCurrency1() {
japod@49:         return currency1;
japod@49:     }
japod@49:             
japod@49:     public String getCurrency2() {
japod@49:         return currency2;
japod@49:     }
japod@49: 
japod@49:     public Rate getRate(){
japod@49:         return rate;
japod@49:     }
japod@49: 
japod@49: }