japod@6: package org.apidesign.apifest08.currency;
japod@6: 
japod@6: import java.io.Serializable;
japod@6: 
japod@6: /**
japod@6:  * Value class, holding an amount of the currency & an identifier of the currency.
japod@6:  * Designed to be an immutable.
japod@6:  * 
japod@6:  * Because of a vague definition of types of the both fields,
japod@6:  * the class has generic types, used as types of the fields.
japod@6:  * These types should be immutable classes, too.
japod@6:  * 
japod@6:  * @author ked
japod@6:  */
japod@6: public final class CurrencyValue<AmountType, IdentifierType> implements Serializable {
japod@6: 
japod@6:     private final AmountType amount;
japod@6:     private final IdentifierType identifier;
japod@6: 
japod@6:     private CurrencyValue(AmountType amount, IdentifierType identifier) {
japod@6:         this.amount = amount;
japod@6:         this.identifier = identifier;
japod@6:     }
japod@6: 
japod@6:     public AmountType getAmount() {
japod@6:         return amount;
japod@6:     }
japod@6: 
japod@6:     public IdentifierType getIdentifier() {
japod@6:         return identifier;
japod@6:     }
japod@6: 
japod@6:     @Override
japod@6:     public boolean equals(Object obj) {
japod@6:         if (obj == null) {
japod@6:             return false;
japod@6:         }
japod@6:         if (getClass() != obj.getClass()) {
japod@6:             return false;
japod@6:         }
japod@6:         final CurrencyValue other = (CurrencyValue) obj;
japod@6:         if (this.amount != other.amount && (this.amount == null || !this.amount.equals(other.amount))) {
japod@6:             return false;
japod@6:         }
japod@6:         if (this.identifier != other.identifier && (this.identifier == null || !this.identifier.equals(other.identifier))) {
japod@6:             return false;
japod@6:         }
japod@6:         return true;
japod@6:     }
japod@6: 
japod@6:     @Override
japod@6:     public int hashCode() {
japod@6:         int hash = 7;
japod@6:         hash = 97 * hash + (this.amount != null ? this.amount.hashCode() : 0);
japod@6:         hash = 97 * hash + (this.identifier != null ? this.identifier.hashCode() : 0);
japod@6:         return hash;
japod@6:     }
japod@6: 
japod@6:     /**
japod@6:      * Creates new instance.
japod@6:      * Generic types of the new instance are derived from types of the parameters.
japod@6:      * 
japod@6:      * @param <AmountType> type of the currency amount
japod@6:      * @param <IdentifierType> type of the currency identifier
japod@6:      * @param amount currency amount
japod@6:      * @param identifier currency identifier
japod@6:      * @return new instance
japod@6:      */
japod@6:     public static <AmountType, IdentifierType> CurrencyValue<AmountType, IdentifierType> getCurrencyValue(AmountType amount, IdentifierType identifier) {
japod@6:         return new CurrencyValue<AmountType, IdentifierType>(amount, identifier);
japod@6:     }
japod@6: }