When I enter a tab in a JTextField after running the attached code, I get the following exception:

Exception occurred during event dispatching:
java.lang.ArrayIndexOutOfBoundsException: 2 > 1
        at java.util.Vector.insertElementAt(Vector.java)
        at com.sun.java.swing.DefaultFocusManager.childrenTabOrder(DefaultFocusManager.java:303)
        at com.sun.java.swing.DefaultFocusManager.getComponentAfter(DefaultFocusManager.java:225)
        at com.sun.java.swing.DefaultFocusManager.getNextComponent(DefaultFocusManager.java:162)
        at com.sun.java.swing.DefaultFocusManager.getFocusableComponentAfter(DefaultFocusManager.java:137)
        at com.sun.java.swing.DefaultFocusManager.focusNextComponent(DefaultFocusManager.java:88)
        at com.sun.java.swing.DefaultFocusManager.processKeyEvent(DefaultFocusManager.java:76)
        at com.sun.java.swing.JComponent.processKeyEvent(JComponent.java:1086)
        at java.awt.Component.processEvent(Component.java:2173)
        at java.awt.Container.processEvent(Container.java:878)
        at java.awt.Component.dispatchEventImpl(Component.java:1773)
        at java.awt.Container.dispatchEventImpl(Container.java:923)
        at java.awt.Component.dispatchEvent(Component.java:1705)
        at java.awt.LightweightDispatcher.processKeyEvent(Container.java:1419)
        at java.awt.LightweightDispatcher.dispatchEvent(Container.java:1403)
        at java.awt.Container.dispatchEventImpl(Container.java:910)
        at java.awt.Window.dispatchEventImpl(Window.java:485)
        at java.awt.Component.dispatchEvent(Component.java:1705)
        at java.awt.EventDispatchThread.run(EventDispatchThread.java:63)


----------- Code --------------


import com.sun.java.swing.*;
import java.awt.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.FocusListener;
import java.awt.event.FocusEvent;

public class TestFocus extends JFrame implements FocusListener, ActionListener {

    int count = 0;
    
    JTextField myTextField1 = new JTextField(20);
    JTextField myTextField2 = new JTextField(20);
    JButton myButton = new JButton("Button");

    public TestFocus() {
        JPanel bottomPanel = new JPanel();
        getContentPane().setLayout(new BorderLayout());
        
        try {
         myTextField1.setNextFocusableComponent(myTextField2); // These are the two lines...
         myTextField2.setNextFocusableComponent(myTextField1); // ... cause the exception.
        } catch(ArrayIndexOutOfBoundsException e) {
         System.out.println("What? " + e);
        }

        bottomPanel.add(myTextField1);
        bottomPanel.add(myTextField2);
        getContentPane().add("Center", bottomPanel);
        getContentPane().add("South", myButton);

        myButton.addActionListener(this);
        myTextField1.addFocusListener(this);
        myTextField2.addFocusListener(this);
        myButton.addFocusListener(this);

myButton.requestFocus();
        myTextField2.requestFocus();
        this.repaint();
    }

    public static void main(String args[]) {
        TestFocus myWindow = new TestFocus();
        myWindow.setTitle("TextField Tab Example");
        myWindow.setSize(400, 400);
        myWindow.setVisible(true);
    }

    public boolean isManagingFocus() {
     return true;
    }
    
    public Component getNextFocusableComponent() {
     return null;
    }
    
    public void actionPerformed(ActionEvent evt) {
        if (evt.getSource() == myButton) {
            /*
             * Get the contents of myTextField1.
             */
            String data1 = myTextField1.getText();
            System.out.println("myTextField = " + data1);

            /*
             * Get the contents of myTextField2.
             */
            String data2 = myTextField2.getText();
            System.out.println("myTextField2 = " + data2);
        }
    }

    public void focusGained(FocusEvent e) {
        System.out.println(++count + " focus gained: " + e.getSource() + "\n");
    }

    public void focusLost(FocusEvent e) {
        System.out.println(++count + " focus lost: " + e.getSource() + "\n");
    }
}

----------- End Of Code --------------