Preventing "Paste" into java applets

Question

First of all, I am sorry that I was not able to search these forums. I searched but the "Sun Search" did not seem to allow a specific forum search and threw more than a page of non-forum hits.
I would like to know whether it is possible to prevent paste (as in copy and paste) into the text field of a java applet as run on a browser as part of an online application.
I know that there are javascript applications for preventing "right click" the use of the control keys and also (the best or most annoying in my experience) flushing the system clipboard.
However, all these measures can be circumvented and I thin that the Opera browser in is good at circumventing them.
When it comes to a java applet however, without interferting with the system, I would have thought it would be possible to control
1) Connections to the system clipboard
2) Which keys can be used to enter into a text field.
So I would have though that preventing paste into a java text field would be possible.
But today I was asked "Do you understand computers"? And made a fool of when I suggested that such a thing may be possible, by a Java programmer. I am surprised.
Is it possible to prevent paste (ctrl v, or using the mouse) into a java text field?
Tim

Answer 1

cleaner way to do it (cleaner meaning not so many inner classes!) is to just add a key adapter to whatever text component you want (textfields, textareas, anything that takes KeyListener)
example..
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
class NoPaste extends KeyAdapter {
     public void keyPressed(KeyEvent e) {
          if (e.isControlDown() && e.getKeyCode() == KeyEvent.VK_V) {
               e.consume();
public class Test extends JFrame {
     public Test() {
          super("Test");
          setDefaultCloseOperation(EXIT_ON_CLOSE);
          addKeyListener(new NoPaste());
          JTextField jf = new JTextField(20);
          Container c = getContentPane();
          c.setLayout(new FlowLayout(FlowLayout.CENTER));
          c.add(new JLabel("Paste: "));
          c.add(new JTextField(20));
          c.add(new JLabel("No Paste: "));
          c.add(jf);
          jf.addKeyListener(new NoPaste());
          pack();
          show();
     public static void main(String[] args) {
          new Test();
}by calling addKeyListener(new NoPaste()); with each component you want, you can disable the ctrl+v key function. the negative side is that a context menu (or any other 3rd party component) could still call paste(), but then again they could call setText anyway, so its not much difference. not to mention Swing does not feature context menus by default..