Two intro-to-GUI applications; both should run, neither do.

Question

LucarioWill 0 Newbie Poster

14 Years Ago

Thanks so much for bothering to look at this n.n;
I've been kind of confused in this class, mainly because I have no idea what the teacher's saying; her English isn't that great, and she has no in-class coding exercises so we're learning entirely from her crappy powerpoints. I'd have been better off just learning directly from the source material....
But I digress. I resisted the allure to just copy off of random websites, mainly because I actually want to learn, and my code is giving me errors attributed to files that aren't even there. I'm kind of wondering what's going on here....
Here's my code:

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JLabel;
import javax.swing.JPanel;
import java.awt.FlowLayout;
import java.awt.BorderLayout;
import javax.swing.*;
public class GUI1 extends JFrame {
    private JLabel resultLabel, firstLabel, message;
    private JTextField fText;
    private JPanel p1, p3, p4, p5, p6;
    private JButton okButton;

    public GUI1(){

        super("First GUI Application");

        p1 = new JPanel();
        p1.setLayout(new FlowLayout(FlowLayout.LEFT));
        firstLabel = new JLabel("Farenheit: ");
        fText = new JTextField(10);
        p1.add(firstLabel);
        p1.add(fText);


                        p3 = new JPanel();
                        p3.setLayout(new FlowLayout(FlowLayout.LEFT));
                        message = new JLabel("Converted temperature:");
                        resultLabel = new JLabel("Converted temperature to go here");
                        p3.add(message);
                        p3.add(resultLabel);

                p4 = new JPanel();
                p4.setLayout(new FlowLayout(FlowLayout.LEFT));
                p4.add(p1,BorderLayout.NORTH);
                p4.add(p3,BorderLayout.SOUTH);

                p5 = new JPanel();
                okButton = new JButton("Convert");
                p5.setLayout(new FlowLayout());
                p5.add(okButton);
                okButton.addActionListener(
                      new ActionListener() {
public void actionPerformed(ActionEvent e) {
         e.getActionCommand();{
         String f = firstLabel.getText();
         float fi = Float.parseFloat(f);
         int c = (int) Math.round((5.0 / 9.0) * (fi - 32));
resultLabel.setText(String.format("%6.2f",c));
      }
   }});
                p6 = new JPanel();
                p6.setLayout(new BorderLayout());
                p6.add(p4,BorderLayout.CENTER);
                p6.add(p5,BorderLayout.SOUTH);
                add(p6);


    }
public static void main (String[]args){
            GUI1 frame = new GUI1();

            frame.setSize(350,140);
            frame.setVisible(true);
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}}

//import needed packages
import java.awt.*;
import javax.swing.*;
public class AlignGrid extends JFrame{
    private JButton okJButton;
    private JButton cancelJButton;
    private JButton helpJButton;
    private JTextField xJTextField, yJTextField;
    private JCheckBox snapJCheckBox, showJCheckBox;
    private JLabel xJLabel, yJLabel;
    private JPanel checkJPanel, buttonJPanel, fieldJPanel1, fieldJPanel2, fieldJPanel;
    public AlignGrid(){
       super ("Align");
       //build checkbox panel
       snapJCheckBox = new JCheckBox("Snap to Grid");
       showJCheckBox = new JCheckBox("Show Grid");
       checkJPanel = new JPanel();
       checkJPanel.setLayout(new GridLayout(2,1));
       //add "snap" checkbox
       checkJPanel.add(snapJCheckBox);
       //add "show" checkbox
       checkJPanel.add(showJCheckBox);
       //build panel1
       xJLabel = new JLabel("X: ");
       xJTextField = new JTextField("8",3);
       fieldJPanel = new JPanel();
       //use flow layout
       fieldJPanel.setLayout(new FlowLayout());
       fieldJPanel.add(xJLabel);
       fieldJPanel.add(xJTextField);
       //build panel2
       yJLabel = new JLabel("Y: ");
       //set text field width to 8*3
       yJTextField = new JTextField("8", 3);
       fieldJPanel2 = new JPanel();
       //use flow layout
       fieldJPanel2.setLayout(new FlowLayout());
       //add yJLabel
       fieldJPanel2.add(yJLabel);
       fieldJPanel2.add(yJTextField);
       //build field panel
       fieldJPanel = new JPanel();
       //use Border layout
       fieldJPanel.setLayout(new BorderLayout());
       fieldJPanel.add (fieldJPanel1,BorderLayout.NORTH);
       fieldJPanel.add (fieldJPanel2, BorderLayout.SOUTH);
       //build button panel
     okJButton = new JButton("OK");
     cancelJButton = new JButton("Cancel");
     helpJButton = new JButton("Help");
     buttonJPanel = new JPanel();
       buttonJPanel.setLayout(new GridLayout(3,1,10,5));
       buttonJPanel.add (okJButton,cancelJButton);
       //use flow layout and align center. Add components.
       setLayout(new FlowLayout(FlowLayout.CENTER, 10, 5));
       add(checkJPanel);
       add(fieldJPanel);
       add(buttonJPanel);
    }
public static void main (String[] args){
      AlignGrid alignGrid = new AlignGrid();
        alignGrid.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //set size of frame
        alignGrid.setSize(300,140);
        //display frame
        alignGrid.setVisible(true);
    }
    //end class
}
 //end constructor

The first assignment was to make a thermometer program with GUI. The second was to recreate a GUI, which should be accurate: if not, I'll scan the book and post it here.

um....
if someone wants a copy of bioshock on steam I'll gift it to you if you help me xD I have an extra....

Thanks in advance!
~Will

PS: here's the exact errors.

for the first program:

Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: "Farenheit:"
        at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1224)
        at java.lang.Float.parseFloat(Float.java:422)
        at GUI1$1.actionPerformed(GUI1.java:47)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
        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:6263)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
        at java.awt.Component.processEvent(Component.java:6028)
        at java.awt.Container.processEvent(Container.java:2041)
        at java.awt.Component.dispatchEventImpl(Component.java:4630)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4574)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
        at java.awt.Container.dispatchEventImpl(Container.java:2085)
        at java.awt.Window.dispatchEventImpl(Window.java:2478)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: "Farenheit:"
        at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1224)
        at java.lang.Float.parseFloat(Float.java:422)
        at GUI1$1.actionPerformed(GUI1.java:47)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
        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:6263)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
        at java.awt.Component.processEvent(Component.java:6028)
        at java.awt.Container.processEvent(Container.java:2041)
        at java.awt.Component.dispatchEventImpl(Component.java:4630)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4574)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
        at java.awt.Container.dispatchEventImpl(Container.java:2085)
        at java.awt.Window.dispatchEventImpl(Window.java:2478)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: "Farenheit:"
        at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1224)
        at java.lang.Float.parseFloat(Float.java:422)
        at GUI1$1.actionPerformed(GUI1.java:47)
        at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:1995)
        at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2318)
        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:6263)
        at javax.swing.JComponent.processMouseEvent(JComponent.java:3267)
        at java.awt.Component.processEvent(Component.java:6028)
        at java.awt.Container.processEvent(Container.java:2041)
        at java.awt.Component.dispatchEventImpl(Component.java:4630)
        at java.awt.Container.dispatchEventImpl(Container.java:2099)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4574)
        at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4238)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4168)
        at java.awt.Container.dispatchEventImpl(Container.java:2085)
        at java.awt.Window.dispatchEventImpl(Window.java:2478)
        at java.awt.Component.dispatchEvent(Component.java:4460)
        at java.awt.EventQueue.dispatchEvent(EventQueue.java:599)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
        at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
        at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

Java Result: 1

for the second program:
Exception in thread "main" java.lang.NullPointerException
at java.awt.Container.addImpl(Container.java:1045)
at java.awt.Container.add(Container.java:927)
at AlignGrid.<init>(AlignGrid.java:48)
at AlignGrid.main(AlignGrid.java:64)
Java Result: 1

java

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5 Replies
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Latest Post 14 Years Ago Latest Post by Ezzaral

BestJewSinceJC 700 Posting Maven

14 Years Ago

String f = firstLabel.getText();
float fi = Float.parseFloat(f);

That is the source of your first error. You are trying to parse "Fahrenheit: " as a float. It is a String. And we don't get rewards for helping people here. Besides which, giving away free copies of BioShock is undoubtedly illegal, so I wouldn't be surprised if one of the moderators here edits that out of your post and gives you an infraction.

Edited 14 Years Ago by BestJewSinceJC because: n/a

Ezzaral 2,714 Posting Sage

14 Years Ago

On line 45

fieldJPanel.add (fieldJPanel1,BorderLayout.NORTH);

you haven't initialized 'fieldJPanel1'. Looks like you mis-typed it up above and set up 'fieldJPanel' twice.

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LucarioWill 0 Newbie Poster · Answer 1 · 2010-03-01T07:30:44+00:00

String f = firstLabel.getText();
float fi = Float.parseFloat(f);
That is the source of your first error. You are trying to parse "Fahrenheit: " as a float. It is a String. And we don't get rewards for helping people here. Besides which, giving away free copies of BioShock is undoubtedly illegal, so I wouldn't be surprised if one of the moderators here edits that out of your post and gives you an infraction.

Thanks for the help! Surprised I didn't already catch that.

Not seeing how it's illegal to give Steam gifts, as it's impossible to have pirated keys on Steam, but I'll remove it if it's against the rules.

LucarioWill 0 Newbie Poster · Answer 2 · 2010-03-01T22:46:59+00:00

Second one's finished; found the error.

I'm still getting errors in the first, however.... any help would be appreciated, thanks!

LucarioWill 0 Newbie Poster · Answer 3 · 2010-03-02T00:19:16+00:00

Sorry, I meant to say the first one is fine and the second is still getting errors. What am I doing wrong? Help!!! :(