int keyInput[] = {
      KeyEvent.VK_D,
      KeyEvent.VK_O,
      KeyEvent.VK_N,
      KeyEvent.VK_E
  };//end keyInput array

Map<String, Integer> keyTextToCode = new HashMap<String, Integer>(256);
Field[] fields = KeyEvent.class.getDeclaredFields();
for (Field field : fields) {
    String name = field.getName();
    if (name.startsWith("VK_")) {
        keyTextToCode.put(name.substring("VK_".length()).toUpperCase(),
                          field.getInt(null));
    }
}

AWTKeyStroke.getAWTKeyStroke('c').getKeyCode();

AWTKeyStroke.getAWTKeyStroke("C").getKeyCode();

public void type(char character) {
    switch (character) {
    case 'a': doType(VK_A); break;
    case 'b': doType(VK_B); break;
    case 'c': doType(VK_C); break;
    case 'd': doType(VK_D); break;
    case 'e': doType(VK_E); break;
    // ...
    case 'A': doType(VK_SHIFT, VK_A); break;
    case 'B': doType(VK_SHIFT, VK_B); break;
    case 'C': doType(VK_SHIFT, VK_C); break;
    // ...
    }
}

javax.swing.JButton but = new javax.swing.JButton();
but.setMnemonic(charVkValue);
int intVkValue = but.getMnemonic());