public static String capitalizeFirstLetter(String str, boolean isUpperCase) {
		if (!isEmpty(str)) {
			char c = str.charAt(0);
			if (isUpperCase) {
				str = (!Character.isLetter(c) || Character.isUpperCase(c)) ? str
						: new StringBuilder(str.length())
								.append(Character.toUpperCase(c))
								.append(str.substring(1)).toString();
			} else {
				str = (!Character.isLetter(c) || Character.isLowerCase(c)) ? str
						: new StringBuilder(str.length())
								.append(Character.toLowerCase(c))
								.append(str.substring(1)).toString();
			}
		}
		return str;
	}