/** * TicketMachine models a naive ticket machine that issues * flat-fare tickets. * The price of a ticket is specified via the constructor. * It is a naive machine in the sense that it trusts its users * to insert enough money before trying to print a ticket. * It also assumes that users enter sensible amounts. * * @author David J. Barnes and Michael Kolling * @version 2008.03.30 */ public class TicketMachine { // The price of a ticket from this machine. private int price; // The amount of money entered by a customer so far. private int balance; // The total amount of money collected by this machine. private int total; /** * Create a machine that issues tickets of the given price. * Note that the price must be greater than zero, and there * are no checks to ensure this. */ public TicketMachine(int ticketCost) { price = ticketCost; balance = 0; total = 0; prompt(); } public TicketMachine() { price = 1000; balance = 0; total = 0; prompt(); } /** * Return the price of a ticket. */ public int getPrice() { return price; } /** * Return the amount of money already inserted for the * next ticket. */ public int getBalance() { return balance; } /** * Receive an amount of money in cents from a customer. */ public void insertMoney(int amount) { if (amount > 0) { balance = balance + amount; } else System.out.println("Use a positive amount: " +amount); if (balance >= price) { total = total + price; balance = balance - price; } else System.out.println("You must insert at least " + (price-balance)+ " more cents."); balance = balance + amount; } /** * Print a ticket. * Update the total collected and * reduce the balance to zero. */ public void printTicket() { int amountLeftToPay = price - balance; if (amountLeftToPay <=0) { // Simulate the printing of a ticket. System.out.println("##################"); System.out.println("# The BlueJ Line"); System.out.println("# Ticket"); System.out.println("# " + price + " cents."); System.out.println("##################"); System.out.println(); } else System.out.println("An additional " +amountLeftToPay+ " cents is required."); // Update the total collected with the balance. total = total + balance; // Clear the balance. balance = 0; } public int getTotal() { return total; } public void prompt() { System.out.println("Please insert the correct amount of money."); } public void showPrice() { System.out.println("The price of a ticket is " + price + "cents."); } public void empty() { total = 0; } public void setPrice(int newPrice) { price = newPrice; } public int emptyMachine() { System.out.println("The total is " + total); total = 0; return total; } }