KeyEvent.consume() doesn't work

Question

I have JFormattedTextField subclassed and implement a KeyListener to avoid typing invalid characters. so i implemented:
     * Implements KeyListener.
    public void keyPressed(KeyEvent event) {
        System.out.println("keyPressed: "+event);
        //verify:
        int keyCode = event.getKeyCode();
        switch (keyCode) {
        case KeyEvent.VK_T :
            System.out.println("valid: "+keyCode);
            break;
        default:
            System.out.println("invalid: "+keyCode);
            event.consume();
            break;
    }//keyPressed()The system out's are correct ("valid", "invalid"), but the invalid characters are still typed in the textfield - even though i call event.consume(). ?

Answer 1

i had to introduce a class variable as a flag and also implement the other methods of KeyListener:
     * Implements KeyListener.
    public void keyPressed(KeyEvent event) {
        //verify:
        int keyCode = event.getKeyCode();
        switch (keyCode) {
        case KeyEvent.VK_T :
        case KeyEvent.VK_ESCAPE :
            isKeyConsumed = false;
            break;
        default:
            event.consume();
            isKeyConsumed = true;
            break;
    }//keyPressed()
     * Implements KeyListener.
    public void keyTyped(KeyEvent event) {
        if (isKeyConsumed) {
            event.consume();
    }//keyTyped()
     * Implements KeyListener.
    public void keyReleased(KeyEvent event) {
       if (isKeyConsumed) {
           event.consume();
    }//keyReleased()not pretty, but it works as expected.