TestKeyboardInput.java

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;

import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public class TestKeyboardInput extends JFrame implements KeyListener {
	private static JTextArea displayArea;
	private static JTextField typingArea;

	@Override
	public void keyTyped(KeyEvent e) {
		char typedChar = e.getKeyChar();
		char transformedChar = (char) (typedChar + 1);
		displayArea.append("You typed: " + typedChar + "\nBut I say it is: " + transformedChar + "\n");
		e.setKeyChar(transformedChar);
	}

	public static void main(String args[]) throws Exception {
		javax.swing.SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				TestKeyboardInput frame = new TestKeyboardInput();
				frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

				typingArea = new JTextField(20);
				typingArea.addKeyListener(frame);
				displayArea = new JTextArea();
				displayArea.setEditable(false);
				JScrollPane scrollPane = new JScrollPane(displayArea);
				scrollPane.setPreferredSize(new Dimension(375, 125));

				frame.getContentPane().add(typingArea, BorderLayout.PAGE_START);
				frame.getContentPane().add(scrollPane, BorderLayout.CENTER);
				frame.pack();
				frame.setVisible(true);
			}
		});
	}

	@Override
	public void keyPressed(KeyEvent e) {
	}

	@Override
	public void keyReleased(KeyEvent e) {
	}
}