public String decode()

in src/main/java/org/apache/commons/text/AlphabetConverter.java [372:407]
31 lines of code
6 McCabe index (conditional complexity)

    public String decode(final String encoded)
            throws UnsupportedEncodingException {
        if (encoded == null) {
            return null;
        }

        final StringBuilder result = new StringBuilder();

        for (int j = 0; j < encoded.length();) {
            final int i = encoded.codePointAt(j);
            final String s = codePointToString(i);

            if (s.equals(originalToEncoded.get(i))) {
                result.append(s);
                j++; // because we do not encode in Unicode extended the
                     // length of each encoded char is 1
            } else {
                if (j + encodedLetterLength > encoded.length()) {
                    throw new UnsupportedEncodingException("Unexpected end "
                            + "of string while decoding " + encoded);
                }
                final String nextGroup = encoded.substring(j,
                        j + encodedLetterLength);
                final String next = encodedToOriginal.get(nextGroup);
                if (next == null) {
                    throw new UnsupportedEncodingException(
                            "Unexpected string without decoding ("
                                    + nextGroup + ") in " + encoded);
                }
                result.append(next);
                j += encodedLetterLength;
            }
        }

        return result.toString();
    }