MyKeyListener.java Source code

Introduction

Here is the source code for MyKeyListener.java

Source

import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.text.BadLocationException;
import javax.swing.text.JTextComponent;

class MyKeyListener extends KeyAdapter {
    public void keyTyped(KeyEvent evt) {
        JTextComponent c = (JTextComponent) evt.getSource();
        char ch = evt.getKeyChar();

        if (Character.isLowerCase(ch) == false) {
            return;
        }
        try {
            c.getDocument().insertString(c.getCaretPosition(), "" + Character.toUpperCase(ch), null);
            evt.consume();
        } catch (BadLocationException e) {
        }
    }
}

public class Main {
    public static void main(String[] argv) throws Exception {
        JTextField component = new JTextField();
        component.addKeyListener(new MyKeyListener());

        JFrame f = new JFrame();
        f.setSize(300, 300);
        f.setVisible(true);
    }
}