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

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+/**
+ * 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 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.
+     * Note that the price must be greater than zero, and there
+     * are no checks to ensure this.
+     */
+    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.
+     */
+    public void insertMoney(int amount)
+    {
+        balance = balance + amount;
+    }
+
+    /**
+     * Print a ticket.
+     * Update the total collected and
+     * reduce the balance to zero.
+     */
+    public void printTicket()
+    {
+        // 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 balance.
+        total = total + balance;
+        // Clear the balance.
+        balance = 0;
+    }
+}