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Semester 1/Programming 1/Java/examples/projects/chapter02/naive-ticket-machine/README.TXT

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+Project: naive-ticket-machine
+Authors: David Barnes and Michael Kölling
+
+This project is part of the material for the book
+
+   Objects First with Java - A Practical Introduction using BlueJ
+   Sixth edition
+   David J. Barnes and Michael Kölling
+   Pearson Education, 2016
+
+It is discussed in chapter 2.
+
+Purpose of project: To illustrate the basics of fields, constructors, and methods.
+How to start this project: Create one or more TicketMachine objects.

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

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+#BlueJ class context
+comment0.params=cost
+comment0.target=TicketMachine(int)
+comment0.text=\n\ Create\ a\ machine\ that\ issues\ tickets\ of\ the\ given\ price.\n\ Note\ that\ the\ price\ must\ be\ greater\ than\ zero,\ and\ there\n\ are\ no\ checks\ to\ ensure\ this.\n
+comment1.params=
+comment1.target=int\ getPrice()
+comment1.text=\n\ Return\ the\ price\ of\ a\ ticket.\n
+comment2.params=
+comment2.target=int\ getBalance()
+comment2.text=\n\ Return\ the\ amount\ of\ money\ already\ inserted\ for\ the\n\ next\ ticket.\n
+comment3.params=amount
+comment3.target=void\ insertMoney(int)
+comment3.text=\n\ Receive\ an\ amount\ of\ money\ from\ a\ customer.\n
+comment4.params=
+comment4.target=void\ printTicket()
+comment4.text=\n\ Print\ a\ ticket.\n\ Update\ the\ total\ collected\ and\n\ reduce\ the\ balance\ to\ zero.\n
+numComments=5

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;
+    }
+}

Semester 1/Programming 1/Java/examples/projects/chapter02/naive-ticket-machine/package.bluej

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+#BlueJ package file
+objectbench.height=89
+objectbench.width=706
+package.editor.height=327
+package.editor.width=598
+package.editor.x=70
+package.editor.y=80
+package.numDependencies=0
+package.numTargets=1
+package.showExtends=true
+package.showUses=true
+project.charset=UTF-8
+readme.editor.height=611
+readme.editor.width=835
+readme.editor.x=53
+readme.editor.y=23
+target1.editor.height=619
+target1.editor.width=777
+target1.editor.x=69
+target1.editor.y=25
+target1.height=60
+target1.name=TicketMachine
+target1.naviview.expanded=true
+target1.showInterface=false
+target1.type=ClassTarget
+target1.typeParameters=
+target1.width=120
+target1.x=170
+target1.y=100