chapter 2 exercies changes

TicketMachine.java

@@ -23,9 +23,9 @@ public class TicketMachine
      * Note that the price must be greater than zero, and there
      * are no checks to ensure this.
      */
-    public TicketMachine(int ticketCost)
+    public TicketMachine()
     {
-        price = ticketCost;
+        price = 1000;
         balance = 0;
         total = 0;
     }
@@ -47,12 +47,23 @@ public class TicketMachine
         return balance;
     }
 
+    public void setPrice(int newPrice) 
+    {
+        price = newPrice;
+    }
+
     /**
      * Receive an amount of money in cents from a customer.
      */
     public void insertMoney(int amount)
-    {
-        balance = balance + amount;
+
+    {if(amount >= 0) {
+            balance = balance + amount;
+        }
+        else {
+            System.out.println("Use a positive amount: " +
+                amount);
+        }
     }
 
     /**
@@ -62,17 +73,45 @@ public class TicketMachine
      */
     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();
+        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();
 
-        // Update the total collected with the balance.
-        total = total + balance;
-        // Clear the balance.
+            // Update the total collected with the balance.
+            total = total + price;
+            // Clear the balance.
+
+        } else {
+            System.out.println("You must insert at least " + amountLeftToPay + " cents.");
+        }
+    }
+
+    public int refundBalance()
+    {
+        int amountToRefund = balance;
         balance = 0;
+        return amountToRefund;
+    }
+
+    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 emptyMachine() 
+    {
+        total = 0;
+    }
+
 }

bluej.pkg

@@ -1,18 +1,18 @@
 #BlueJ package file
 editor.fx.0.height=722
-editor.fx.0.width=800
-editor.fx.0.x=709
-editor.fx.0.y=113
+editor.fx.0.width=676
+editor.fx.0.x=755
+editor.fx.0.y=47
 objectbench.height=101
-objectbench.width=461
-package.divider.horizontal=0.6
-package.divider.vertical=0.8007380073800738
-package.editor.height=427
-package.editor.width=674
-package.editor.x=1067
-package.editor.y=119
-package.frame.height=600
-package.frame.width=800
+objectbench.width=349
+package.divider.horizontal=0.6425992779783394
+package.divider.vertical=0.8078291814946619
+package.editor.height=447
+package.editor.width=448
+package.editor.x=859
+package.editor.y=23
+package.frame.height=620
+package.frame.width=574
 package.numDependencies=0
 package.numTargets=1
 package.showExtends=true

package.bluej

@@ -1,18 +1,18 @@
 #BlueJ package file
 editor.fx.0.height=722
-editor.fx.0.width=800
-editor.fx.0.x=709
-editor.fx.0.y=113
+editor.fx.0.width=676
+editor.fx.0.x=755
+editor.fx.0.y=47
 objectbench.height=101
-objectbench.width=461
-package.divider.horizontal=0.6
-package.divider.vertical=0.8007380073800738
-package.editor.height=427
-package.editor.width=674
-package.editor.x=1067
-package.editor.y=119
-package.frame.height=600
-package.frame.width=800
+objectbench.width=349
+package.divider.horizontal=0.6425992779783394
+package.divider.vertical=0.8078291814946619
+package.editor.height=447
+package.editor.width=448
+package.editor.x=859
+package.editor.y=23
+package.frame.height=620
+package.frame.width=574
 package.numDependencies=0
 package.numTargets=1
 package.showExtends=true