in JAVA code

/** * An encapsulation of a gift card that can be used to * make purchases at a retil store. */ public class GiftCard { private static final int MAX_ID = 9999;

private double balance; private int issuingStore;

/** * Explicit Value Constructor. * * @param storeID The ID of the issuing store * @param openingBalance The opening balance on the card * @throws IllegalArgumentException If either parameter is "illegal" */ public GiftCard(int storeID, double openingBalance) throws IllegalArgumentException { if (storeID < 0 || storeID > MAX_ID) { throw new IllegalArgumentException("Illegal Store ID: " + storeID); } else { issuingStore = storeID; }

if (openingBalance < 0.00) { throw new IllegalArgumentException("Illegal Balance: " + openingBalance); } else { balance = openingBalance; } }

/** * Deduct a (purchase) amount from this GiftCard. * * @param amount The amount to deduct * @return A message describing the result of the transaction */ public String deduct(double amount) { String result; if (amount < 0.0) { result = "Invalid Transaction"; } else { balance -= amount; if (balance < 0.0) { result = "Amount Due: " + String.format("%6.2f", Math.abs(balance)); balance = 0.0; } else { result = "Remaining Balance: " + String.format("%6.2f", Math.abs(balance)); } } return result; }

/** * Get the remaining balance on this GiftCard. * * @return The balance */ public double getBalance() { return balance; }

/** * Get the ID of the issuing store. * * @return The ID */ public int getIssuingStore() { return issuingStore; } }