org.apache.commons.lang3.StringUtils#capitalize

    public static String capitalize(final String str) {
        int strLen;
        if (str == null || (strLen = str.length()) == 0) {
            return str;
        }

        final char firstChar = str.charAt(0);
        if (Character.isTitleCase(firstChar)) {
            // already capitalized
            return str;
        }

        return new StringBuilder(strLen)
            .append(Character.toTitleCase(firstChar))
            .append(str.substring(1))
            .toString();
    }