FULL PRODUCT VERSION :
java version "1.4.2_08"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_08-b03)
Java HotSpot(TM) Client VM (build 1.4.2_08-b03, mixed mode)



ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP Version 2002

A DESCRIPTION OF THE PROBLEM :
I have designed a GUI, where I take inputs from a textField.
I have to validate the input values in a JTextField in focusLost event. If the input in the JTextField is incorrect I show an error message to the user (I am using JOptionPane) and put the focus back to the JTextField.

Result Observed: The the error message is showing multiple times. After debugging I found that the focusLost Event is triggered multiple times for the grabFocus of the text field.



REPRODUCIBILITY :
This bug can be reproduced always.


---------- BEGIN SOURCE ----------
import java.awt.event.FocusEvent;
import javax.swing.JOptionPane;
import javax.swing.JTextField;


public class NewJFrame extends javax.swing.JFrame {
    
    /** Creates new form NewJFrame */
    public NewJFrame() {
        initComponents();
    }
    
    /** This method is called from within the constructor to
     * initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is
     * always regenerated by the Form Editor.
     */
    // <editor-fold defaultstate="collapsed" desc=" Generated Code ">
    private void initComponents() {
        jTextField1 = new javax.swing.JTextField();
        jCheckBox1 = new javax.swing.JCheckBox();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        jTextField1.setText("jTextField1");
        jTextField1.addFocusListener(new java.awt.event.FocusAdapter() {
            public void focusLost(java.awt.event.FocusEvent evt) {
                jTextField1FocusLost(evt);
            }
        });

        getContentPane().add(jTextField1, java.awt.BorderLayout.SOUTH);

        jCheckBox1.setText("jCheckBox1");
        jCheckBox1.setBorder(javax.swing.BorderFactory.createEmptyBorder(0, 0, 0, 0));
        jCheckBox1.setMargin(new java.awt.Insets(0, 0, 0, 0));
        getContentPane().add(jCheckBox1, java.awt.BorderLayout.CENTER);

        pack();
    }// </editor-fold>

    private void jTextField1FocusLost(java.awt.event.FocusEvent evt) {
        focusLost(evt);
    }
    
    public void focusLost(FocusEvent e){
        Object obj = e.getSource();
        JTextField textField = new JTextField();

        if (textField instanceof JTextField) {
            textField = (JTextField) obj;
            String value = textField.getText();

            try {
                Integer.parseInt(value);
            }
            catch (NumberFormatException ex) {
                System.out.println("User entered wrong value");
                JOptionPane.showMessageDialog(jTextField1,
                        "Please enter a numeric value",
                        "Error",
                        JOptionPane.ERROR_MESSAGE);
                textField.setText("");
                textField.grabFocus();
                return;
            }
        }
    }
    
    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new NewJFrame().setVisible(true);
            }
        });
    }
    
    // Variables declaration - do not modify
    private javax.swing.JCheckBox jCheckBox1;
    private javax.swing.JTextField jTextField1;
    // End of variables declaration
    
}
---------- END SOURCE ----------