import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import javax.swing.JComboBox;
public class Main {
public static void main(String[] argv) throws Exception {
String[] items = { "A", "A", "B", "B", "C", "C" };
JComboBox cb = new JComboBox(items);
// Create and register the key listener
cb.addKeyListener(new MyKeyListener());
}
}
class MyKeyListener extends KeyAdapter {
public void keyPressed(KeyEvent evt) {
JComboBox cb = (JComboBox) evt.getSource();
// Get pressed character
char ch = evt.getKeyChar();
// If not a printable character, return
if (ch != KeyEvent.CHAR_UNDEFINED) {
cb.showPopup();
}
}
}