public static boolean isBase32(String data) {
        return data == null ? false : Base32Hex.isInAlphabet(data.toUpperCase());
    }
Validates a string to ensure all its bytes are in the Base32 alphabet.
Implementation is case-insensitive and converts the given string to 
upper case before evaluating.

@param data the string to test
@return True if the given string can be decoded using Base32
xmppserver/src/main/java/org/jivesoftware/util/StringUtils.java