if (StringUtil.isBlank(enc)) {
            return defaultEncoding;
        }

        final String newEnc = encodingMap.get(toLowerCase(enc));
        if (StringUtil.isBlank(newEnc)) {
            return enc;
        }
        return newEnc;
    }

    /**
     * Sets the default encoding to use when no mapping is found.
     *
     * @param defaultEncoding the default encoding to set