You have to implement KeyListener
,take a look here:
http://docs.oracle.com/javase/7/docs/api/java/awt/event/KeyListener.html
More details on how to use it: http://docs.oracle.com/javase/tutorial/uiswing/events/keylistener.html
Try this:
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class Main {
public static void main(String[] argv) throws Exception {
JTextField textField = new JTextField();
textField.addKeyListener(new Keychecker());
JFrame jframe = new JFrame();
jframe.add(textField);
jframe.setSize(400, 350);
jframe.setVisible(true);
}
class Keychecker extends KeyAdapter {
@Override
public void keyPressed(KeyEvent event) {
char ch = event.getKeyChar();
System.out.println(event.getKeyChar());
}
}
Source: Stackoverflow.com