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Semester 1/Programming 1/Java/examples/projects/chapter02/better-ticket-machine/TicketMachine.java

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+/**
+ * TicketMachine models a ticket machine that issues
+ * flat-fare tickets.
+ * The price of a ticket is specified via the constructor.
+ * Instances will check to ensure that a user only enters
+ * sensible amounts of money, and will only print a ticket
+ * if enough money has been input.
+ * 
+ * @author David J. Barnes and Michael Kölling
+ * @version 2016.02.29
+ */
+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.
+     */
+    public TicketMachine(int cost)
+    {
+        price = cost;
+        balance = 0;
+        total = 0;
+    }
+
+    /**
+     * @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 from a customer.
+     * Check that the amount is sensible.
+     */
+    public void insertMoney(int amount)
+    {
+        if(amount > 0) {
+            balance = balance + amount;
+        }
+        else {
+            System.out.println("Use a positive amount rather than: " +
+                               amount);
+        }
+    }
+
+    /**
+     * Print a ticket if enough money has been inserted, and
+     * reduce the current balance by the ticket price. Print
+     * an error message if more money is required.
+     */
+    public void printTicket()
+    {
+        if(balance >= price) {
+            // 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();
+
+            // Update the total collected with the price.
+            total = total + price;
+            // Reduce the balance by the price.
+            balance = balance - price;
+        }
+        else {
+            System.out.println("You must insert at least: " +
+                               (price - balance) + " more cents.");
+                    
+        }
+    }
+
+    /**
+     * Return the money in the balance.
+     * The balance is cleared.
+     */
+    public int refundBalance()
+    {
+        int amountToRefund;
+        amountToRefund = balance;
+        balance = 0;
+        return amountToRefund;
+    }
+}