japod@6: package org.apidesign.apifest08.currency;
japod@6: 
japod@6: import java.math.BigDecimal;
japod@6: import java.util.Currency;
japod@6: 
japod@6: /**
japod@6:  * An amount of a currency.
japod@6:  * Immutable.
japod@6:  * @author jdvorak
japod@6:  */
japod@6: public class MonetaryAmount {
japod@6: 
japod@6:     private final BigDecimal amount;
japod@6:     private final Currency currency;
japod@6:     
japod@6:     /**
japod@6:      * A new amount.
japod@6:      * @param amount the quantity of the currency; must not be null
japod@6:      * @param currency the currency; must not be null
japod@6:      */
japod@6:     public MonetaryAmount( final BigDecimal amount, final Currency currency ) {
japod@6:         this.amount = amount;
japod@6:         this.currency = currency;
japod@6:         if ( amount == null ) {
japod@6:             throw new NullPointerException( "The amount" );
japod@6:         }
japod@6:         if ( currency == null ) {
japod@6:             throw new NullPointerException( "The currency" );
japod@6:         }
japod@6:     }
japod@6:     
japod@6:     /**
japod@6:      * A new amount.
japod@6:      * @param amount the quantity of the currency; must not be null
japod@6:      * @param currency the currency; must not be null
japod@6:      */
japod@6:     public MonetaryAmount( final double amount, final Currency currency ) {
japod@6:         this( new BigDecimal( amount ), currency );
japod@6:     }
japod@6:     
japod@6:     /**
japod@6:      * The amount.
japod@6:      * @return the amount
japod@6:      */
japod@6:     public BigDecimal getAmount() {
japod@6:         return amount;
japod@6:     }
japod@6:     
japod@6:     /**
japod@6:      * The currency.
japod@6:      * @return the currency
japod@6:      */
japod@6:     public Currency getCurrency() {
japod@6:         return currency;
japod@6:     }
japod@6: 
japod@6:     /**
japod@6:      * The string representation of the monetary amount.
japod@6:      * @return the amount, a non-breakable space, the currency
japod@6:      */
japod@6:     @Override
japod@6:     public String toString() {
japod@6:         return amount.toPlainString() + "\u00a0" + currency.toString();
japod@6:     }
japod@6:     
japod@6:     /**
japod@6:      * Two monetary amounts are equal to each other iff they have equal amounts of equal currencies.
japod@6:      * @param other the other object
japod@6:      * @return equality
japod@6:      */
japod@6:     @Override
japod@6:     public boolean equals( final Object other ) {
japod@6:         if ( other instanceof MonetaryAmount ) {
japod@6:             final MonetaryAmount otherMonetaryAmount = (MonetaryAmount) other;
japod@6:             return getAmount().equals( otherMonetaryAmount.getAmount() ) && getCurrency().equals( otherMonetaryAmount.getCurrency() );
japod@6:         }
japod@6:         return false;
japod@6:     }
japod@6:     
japod@6:     /**
japod@6:      * The hash code combines the hash codes of the amount and of the currency.
japod@6:      * @return hash code
japod@6:      */
japod@6:     @Override
japod@6:     public int hashCode() {
japod@6:         return amount.hashCode() * 37 + currency.hashCode();
japod@6:     }
japod@6:     
japod@6: }