Runtime problem in custom program

Question

I have created a program awhile back that calculates the sales tax and total price for a product. I successfully compiled and ran the terminal version, but due to some problems, I decided to make a GI version. However, I'm having problems. After what felt like many trials and error, I finally got it to compile and show the window but after typing in the info to test my program, the dialog box will not show up with the results. here is the code I put into the program.
import javax.swing.*;
import java.text.*;
import java.awt.*;
import java.lang.*;
import java.awt.event.*;
class SwingWindow extends JFrame
          JLabel messageLabel;
          JLabel messageLabel2;
          JTextField num1;
          JTextField num2;
          JButton calcButton;
          JPanel panel;
     public SwingWindow()
          super("Sales Tax calculator");
          setSize(400, 150);
          setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          messageLabel = new JLabel("Enter your sales tax rate:");
          num1 = new JTextField(10);
          messageLabel2 = new JLabel("Enter the listed price of the product:");
          num2 = new JTextField(10);
          calcButton = new JButton("Calculate");
          calcButton.addActionListener(new CalcButtonListener());
          panel = new JPanel();
          panel.add(messageLabel);
          panel.add(num1);
          panel.add(messageLabel2);
          panel.add(num2);
          panel.add(calcButton);
          setVisible(true);
          Container contentArea = getContentPane();
          contentArea.setBackground(Color.white);
          contentArea.add(panel);
          setContentPane(contentArea);
     private class CalcButtonListener implements ActionListener
          public void actionPerformed(ActionEvent e)
               NumberFormat cf = NumberFormat.getCurrencyInstance();
               String str1;
               String str2;
               float rate;
               float total;
               str1 = num1.getText();
               str2 = num2.getText();
               rate = Float.parseFloat(str1) * Float.parseFloat(str2);
               total = rate + Float.parseFloat(str2);
               JOptionPane.showMessageDialog(null, cf.format(str2) + "is the listed price and" + str1 + "is your sales tax rate and" + cf.format(rate) + "is the sales tax for the product and" + cf.format(total) + "is the overall cost for the product.");
public class Salestax
     public static void main(String[] args)
          SwingWindow Salestax = new SwingWindow();
}What can I do or need to do to make that dialog box appear when the Calculate button is clicked? I looked at a tutorial on frames from Sun, but I had troubles compiling afterwards. I'm using Java version 6, if that helps any.
Edited by: gotenks05 on Sep 18, 2008 11:54 AM

Answer 1

Hello, I'm the one who posted this thread this is just a different name because I could not figure out how to get back under the name I posted as. I know that when compiling being syntax error free does not guarantee an error free runtime, but nobody can run a program if it is not or cannot be compiled. This is why I need help. I want the dialog box to appear and the code to be syntax error free. When I ran the program from terminal, I got the following:
Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: Cannot format given Object as a Number     at java.text.DecimalFormat.format(DecimalFormat.java:487)
     at java.text.Format.format(Format.java:140)
     at SwingWindow$CalcButtonListener.actionPerformed(Salestax.java:51)
     at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2028)
     at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2351)
     at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
     at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
     at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:236)
     at java.awt.Component.processMouseEvent(Component.java:6126)
     at javax.swing.JComponent.processMouseEvent(JComponent.java:3265)
     at java.awt.Component.processEvent(Component.java:5891)
     at java.awt.Container.processEvent(Container.java:2102)
     at java.awt.Component.dispatchEventImpl(Component.java:4497)
     at java.awt.Container.dispatchEventImpl(Container.java:2160)
     at java.awt.Component.dispatchEvent(Component.java:4327)
     at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4366)
     at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4030)
     at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3960)
     at java.awt.Container.dispatchEventImpl(Container.java:2146)
     at java.awt.Window.dispatchEventImpl(Window.java:2440)
     at java.awt.Component.dispatchEvent(Component.java:4327)
     at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
     at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:300)
     at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:210)
     at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:200)
     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:195)
     at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:187)
     at java.awt.EventDispatchThread.run(EventDispatchThread.java:121)>
I know there is something that needs to be done with the source, but I don't what it is, especially since I did not get this problem when I compiled the text based version.
update: I got the dialog box to show, but I want the numbers in currency format.
update 2: I finally got the result I wanted, with a bit of tweaking thanks for the help so far given. I just made another variable to show the number as a float, then used cf.format for currency.
Edited by: realgotenks05 on Sep 18, 2008 1:55 PM
Edited by: realgotenks05 on Sep 18, 2008 2:10 PM