setText Not Working

**mattpotter28** · May 15th, 2012, 07:52 AM

Hi, I'm taking my first Computer Science class currently and have come to a problem with one of my codes.

// Tutorial 5: Inventory.java
// Calculates the number of items in a shipment based on the number
// of cartons received and the number of items per carton.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Inventory extends JFrame
{
   // JLabel and JTextField for cartons per shipment
   private JLabel cartonsJLabel;
   public JTextField cartonsJTextField;
   // JLabel and JTextField for items per carton
   public JLabel itemsJLabel;
   public JTextField itemsJTextField;
   // JLabel and JTextField for total items per shipment
   private JLabel totalJLabel;
   public JTextField totalResultJTextField;
   // JButton to initiate calculation of total items per shipment
   private JButton calculateJButton;
   // no-argument constructor
   public Inventory()
   {
      createUserInterface();
   }
   // create and position GUI components; register event handlers
   public void createUserInterface()
   {
      // get content pane and set layout to null
      Container contentPane = getContentPane();
      contentPane.setLayout( null );
      // set up cartonsJLabel
      cartonsJLabel = new JLabel();
      cartonsJLabel.setText( "Cartons per shipment:" );
	  cartonsJLabel.setBounds( 16, 16, 130, 21 );
      contentPane.add( cartonsJLabel );
      // set up itemsJLabel
      itemsJLabel = new JLabel();
      itemsJLabel.setText("Items per Carton:");
	  itemsJLabel.setBounds(16, 48, 104, 21);
      contentPane.add( itemsJLabel );
      // set up totalJLabel
      totalJLabel = new JLabel();
      totalJLabel.setText("Total:");
	  totalJLabel.setBounds(204, 16, 40, 21);
      contentPane.add( totalJLabel );
      // set up cartonsJTextField
      cartonsJTextField = new JTextField();
      cartonsJTextField.setText("0");
	  cartonsJTextField.setBounds( 148, 16, 40, 21 );
	  cartonsJTextField.setHorizontalAlignment(JTextField.RIGHT);
      contentPane.add( cartonsJTextField );
      // set up itemsJTextField
      itemsJTextField = new JTextField();
      itemsJTextField.setText("0");
	  itemsJTextField.setBounds( 148, 48, 40, 21 );
	  itemsJTextField.setHorizontalAlignment(JTextField.RIGHT);
      contentPane.add( itemsJTextField );
      // set up totalResultJTextField
      totalResultJTextField = new JTextField();
      totalResultJTextField.setBounds( 244, 16, 86, 21 );
	  totalResultJTextField.setHorizontalAlignment(
		  JTextField.RIGHT);
	  totalResultJTextField.setEditable( false );
      contentPane.add( totalResultJTextField );
      // set up calculateJButton
      calculateJButton = new JButton();
      calculateJButton.setText("Calculate Total");
	  calculateJButton.setBounds(204, 48, 126, 24);
      contentPane.add( calculateJButton );
      calculateJButton.addActionListener(
      	   new ActionListener() // anonymous inner class
         {
            // event handler called when calculateJButton is pressed
            public void actionPerformed( ActionEvent event )
            {
               calculateJButtonActionPerformed( event );
            }
         } // end anonymous inner class
      ); // end call to addActionListener
      // set properties of application’s window
      setTitle( "Inventory" ); // set title bar text
      setSize( 354, 112 );     // set window size
      setVisible( true );      // display window
   } // end method createUserInterface
   //calculate the total items in the shipment
	public void calculateJButtonActionPerformed( ActionEvent event )
	{
		int cartons; // stores number of cartons
		int items;
		int result;
		//retrieve number from JTextFields
		cartons = Integer.parseInt( cartonsJTextField.getText() );
		items = Integer.parseInt( itemsJTextField.getText() );
		result = cartons * items;
		totalResultJTextField.setText( String.valueOf( result ) );
	} // end method calculateJButtonActionPerformed
   public void cartonsJTextFieldKeyPressed( KeyEvent event )
   {
   		totalResultJTextField.setText( "" );
 
   }
   public void itemsJTextFieldKeyPressed( KeyEvent event )
   {
   		totalResultJTextField.setText( "" );
 
   }
	public static void main( String[] args )
   {
      Inventory application = new Inventory();
      application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
   }
}

The program runs correctly by calculating, but the setText when KeyPressed doesn't work. Thanks in advance for your help.

**KevinWorkman** · May 15th, 2012, 07:55 AM

Code should be posted in the form of an SSCCE - that's a lot of code to demonstrate a single keyPressed and setText call, and your indentation makes the code pretty hard to read.

I recommend you get rid of all the extra, then tell us exactly which line you're talking about, as well as what you mean by "doesn't work".

Recommended reading: http://www.javaprogrammingforums.com...t-println.html

**mattpotter28** · May 15th, 2012, 08:00 AM

Alright, here's the part I'm having trouble with.

   public void cartonsJTextFieldKeyPressed( KeyEvent event )
   {
   		totalResultJTextField.setText( "" );
 
   }
   public void itemsJTextFieldKeyPressed( KeyEvent event )
   {
   		totalResultJTextField.setText( "" );
 
   }

And when I say it doesn't work, I mean that when I press a key to get rid of what is already in the box, I want it to delete what's in the totalResult box.

**KevinWorkman** · May 15th, 2012, 08:04 AM

An SSCCE should still be runnable simply by copying and pasting it into an editor. For your case, your program should just be a single JTextField with whatever listener you're trying to get to work.

When are those methods called? When do you add the KeyListener? What do you add it to?