String calculateRawEncoding()

in src/main/java/org/apache/commons/io/input/XmlStreamReader.java [783:838]
46 lines of code
27 McCabe index (conditional complexity)

    String calculateRawEncoding(final String bomEnc, final String xmlGuessEnc, final String xmlEnc) throws IOException {

        // BOM is Null
        if (bomEnc == null) {
            if (xmlGuessEnc == null || xmlEnc == null) {
                return defaultEncoding == null ? UTF_8 : defaultEncoding;
            }
            if (xmlEnc.equals(UTF_16) && (xmlGuessEnc.equals(UTF_16BE) || xmlGuessEnc.equals(UTF_16LE))) {
                return xmlGuessEnc;
            }
            return xmlEnc;
        }

        // BOM is UTF-8
        if (bomEnc.equals(UTF_8)) {
            if (xmlGuessEnc != null && !xmlGuessEnc.equals(UTF_8)) {
                final String msg = MessageFormat.format(RAW_EX_1, bomEnc, xmlGuessEnc, xmlEnc);
                throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
            }
            if (xmlEnc != null && !xmlEnc.equals(UTF_8)) {
                final String msg = MessageFormat.format(RAW_EX_1, bomEnc, xmlGuessEnc, xmlEnc);
                throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
            }
            return bomEnc;
        }

        // BOM is UTF-16BE or UTF-16LE
        if (bomEnc.equals(UTF_16BE) || bomEnc.equals(UTF_16LE)) {
            if (xmlGuessEnc != null && !xmlGuessEnc.equals(bomEnc)) {
                final String msg = MessageFormat.format(RAW_EX_1, bomEnc, xmlGuessEnc, xmlEnc);
                throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
            }
            if (xmlEnc != null && !xmlEnc.equals(UTF_16) && !xmlEnc.equals(bomEnc)) {
                final String msg = MessageFormat.format(RAW_EX_1, bomEnc, xmlGuessEnc, xmlEnc);
                throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
            }
            return bomEnc;
        }

        // BOM is UTF-32BE or UTF-32LE
        if (bomEnc.equals(UTF_32BE) || bomEnc.equals(UTF_32LE)) {
            if (xmlGuessEnc != null && !xmlGuessEnc.equals(bomEnc)) {
                final String msg = MessageFormat.format(RAW_EX_1, bomEnc, xmlGuessEnc, xmlEnc);
                throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
            }
            if (xmlEnc != null && !xmlEnc.equals(UTF_32) && !xmlEnc.equals(bomEnc)) {
                final String msg = MessageFormat.format(RAW_EX_1, bomEnc, xmlGuessEnc, xmlEnc);
                throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
            }
            return bomEnc;
        }

        // BOM is something else
        final String msg = MessageFormat.format(RAW_EX_2, bomEnc, xmlGuessEnc, xmlEnc);
        throw new XmlStreamReaderException(msg, bomEnc, xmlGuessEnc, xmlEnc);
    }