Ghost in the code
Here's a weird one. I compile and run this code, and get Bob Jones as the account holder, and a Withdrawel <sic> JTextField where there should not be one. Anybody help me on this one?
I just can't figure this out. I sent in the code to my teacher, and he says he can't figure it out, either. How can the text, "Bob Jones", appear, when it does not exist anywhere in the code?
Flummoxed.
Code:
// Exercise 4.16: AccountInformation.java
// This application inputs and outputs account information.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
public class AccountInformation extends JFrame
{
// JPanel to group deposit components
private JPanel enterJPanel;
// JLabel and JTextField for deposits
private JLabel depositJLabel;
private JTextField depositJTextField;
// JButton to initiate balance calculation
private JButton enterJButton;
// JPanel to group account information components
private JPanel accountJPanel;
// JLabel and JTextField for account holder's name
private JLabel nameJLabel;
private JTextField nameJTextField;
// JLabel and JTextField for account number
private JLabel accountNumberJLabel;
private JTextField accountNumberJTextField;
// JLabel and JTextField for balance
private JLabel balanceJLabel;
private JTextField balanceJTextField;
// no-argument constructor
public AccountInformation()
{
createUserInterface();
}
// create and position GUI components; register event handlers
private void createUserInterface()
{
// get content pane and set layout to null
Container contentPane = getContentPane();
contentPane.setLayout( null );
// set up enterJPanel
enterJPanel = new JPanel();
enterJPanel.setLayout( null );
enterJPanel.setBounds( 16, 16, 152, 126 );
enterJPanel.setBorder(
new TitledBorder( "Enter information" ) );
contentPane.add( enterJPanel );
// set up depositJLabel
depositJLabel = new JLabel();
depositJLabel.setText( "Deposit amount:" );
depositJLabel.setBounds( 16, 40, 140, 16 );
enterJPanel.add( depositJLabel );
// set up depositJTextField
depositJTextField = new JTextField();
depositJTextField.setText( "0" );
depositJTextField.setBounds( 16, 56, 120, 21 );
depositJTextField.setHorizontalAlignment( JTextField.RIGHT );
enterJPanel.add( depositJTextField );
// set up enterJButton
enterJButton = new JButton();
enterJButton.setText( "Enter" );
enterJButton.setBounds( 16, 150, 152, 34 );
contentPane.add( enterJButton );
enterJButton.addActionListener(
new ActionListener() // anonymous inner class
{
// event handler called when enterJButton is pressed
public void actionPerformed( ActionEvent event )
{
enterJButtonActionPerformed( event );
}
} // end anonymous inner class
); // end call to addActionListener
// set up accountJPanel
accountJPanel = new JPanel();
accountJPanel.setLayout( null );
accountJPanel.setBounds( 180, 16, 136, 170 );
accountJPanel.setBorder(
new TitledBorder( "Account information" ) );
contentPane.add( accountJPanel );
// set up nameJLabel
nameJLabel = new JLabel();
nameJLabel.setText( "Name:" );
nameJLabel.setBounds( 16, 24, 100, 16 );
accountJPanel.add( nameJLabel );
// set up nameJTextField
nameJTextField = new JTextField();
nameJTextField.setText( "Sue Purple" );
nameJTextField.setBounds( 16, 40, 104, 21 );
nameJTextField.setEditable( false );
accountJPanel.add( nameJTextField );
// set up accountNumberJLabel
accountNumberJLabel = new JLabel();
accountNumberJLabel.setText( "Account Number:" );
accountNumberJLabel.setBounds( 16, 70, 140, 16 );
accountJPanel.add( accountNumberJLabel );
// set up accountNumberJTextField
accountNumberJTextField = new JTextField();
accountNumberJTextField.setText( "12345" );
accountNumberJTextField.setBounds( 16, 86, 104, 21 );
accountNumberJTextField.setEditable( false );
accountNumberJTextField.setHorizontalAlignment(
JTextField.RIGHT );
accountJPanel.add( accountNumberJTextField );
// set up balanceJLabel
balanceJLabel = new JLabel();
balanceJLabel.setText( "Balance:" );
balanceJLabel.setBounds( 16, 116, 100, 16 );
accountJPanel.add( balanceJLabel );
// set up balanceJTextField
balanceJTextField = new JTextField();
balanceJTextField.setText( "0" );
balanceJTextField.setBounds( 16, 132, 104, 21 );
balanceJTextField.setEditable( false );
balanceJTextField.setHorizontalAlignment( JTextField.RIGHT );
accountJPanel.add( balanceJTextField );
// set properties of application's window
setTitle( "Account Information" ); // set title bar text
setSize( 325, 225 ); // set window size
setVisible( true ); // display window
} // end method createUserInterface
// method called when enterJButton is pressed
private void enterJButtonActionPerformed( ActionEvent event )
{
// display new balance
balanceJTextField.setText( String.valueOf(
Integer.parseInt( depositJTextField.getText() ) -
Integer.parseInt( withdrawelJTextField.getText() ) ) );
// clear depositJTextField
depositJTextField.setText( "0" );
} // end method enterJButtonActionPerformed
// main method
public static void main( String[] args )
{
AccountInformation application = new AccountInformation();
application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
} // end method main
} // end class AccountInformation
I just can't figure this out. I sent in the code to my teacher, and he says he can't figure it out, either. How can the text, "Bob Jones", appear, when it does not exist anywhere in the code?
Flummoxed.
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