How to moniter and Replace every character typed into a JTextArea!

Question

I have a JTextArea!
For every character typed on it in want to change that character to my own character...
For example if user types 'a' on key board, i want 'b' to be displayed on the JTextArea.
It should been seen on the screen...
Any idea?
P.N: I am doing a notepad like editor where in user can type Indic languages in phonetic notation... [Yea, Transliteration....] Does any one have any coding for that, Especially for Tamil... I want to get அம்மா, if i type "amma". I have the table of what should be replace with what! but i don't know how to make it work? any idea?

Answer 1

if user types 'a' on key board, i want 'b' to be displayed on the JTextArea.Add a KeyListener and override the keyTyped method to increment the keyChar field of the KeyEvent.
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.SwingUtilities;
public class KeyShifter {
  public static void main(String[] args) {
   SwingUtilities.invokeLater(new Runnable() {
     public void run() {
       new KeyShifter().makeUI();
  void makeUI() {
    JTextArea textArea = new JTextArea();
    textArea.addKeyListener(new KeyAdapter() {
      public void keyTyped(KeyEvent ke) {
        char c = (char) (ke.getKeyChar() + 1);
        ke.setKeyChar(c);
    JFrame frame = new JFrame("Key Shifter");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(200, 200);
    frame.add(textArea);
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
So maybe it'd be better to have two text fields... one what was typed (as per normal) and a JTextArea to display the transliterated text. Just an idea.And a very good idea, Keith... just testing this was creepy! Yup, this could be recoded to append a character other than the one typed, to a second, uneditable, text area. I'd use a Map or some other data structure to get the transliterated character from the one typed.
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