public static String unescapeSQLString()

in flink-connector-hive/src/main/java/org/apache/flink/table/planner/delegation/hive/copy/HiveParserBaseSemanticAnalyzer.java [611:710]
88 lines of code
30 McCabe index (conditional complexity)

    public static String unescapeSQLString(String b) {
        Character enclosure = null;

        // Some of the strings can be passed in as unicode. For example, the
        // delimiter can be passed in as \002 - So, we first check if the
        // string is a unicode number, else go back to the old behavior
        StringBuilder sb = new StringBuilder(b.length());
        for (int i = 0; i < b.length(); i++) {

            char currentChar = b.charAt(i);
            if (enclosure == null) {
                if (currentChar == '\'' || b.charAt(i) == '\"') {
                    enclosure = currentChar;
                }
                // ignore all other chars outside the enclosure
                continue;
            }

            if (enclosure.equals(currentChar)) {
                enclosure = null;
                continue;
            }

            if (currentChar == '\\' && (i + 6 < b.length()) && b.charAt(i + 1) == 'u') {
                int code = 0;
                int base = i + 2;
                for (int j = 0; j < 4; j++) {
                    int digit = Character.digit(b.charAt(j + base), 16);
                    code = (code << 4) + digit;
                }
                sb.append((char) code);
                i += 5;
                continue;
            }

            if (currentChar == '\\' && (i + 4 < b.length())) {
                char i1 = b.charAt(i + 1);
                char i2 = b.charAt(i + 2);
                char i3 = b.charAt(i + 3);
                if ((i1 >= '0' && i1 <= '1')
                        && (i2 >= '0' && i2 <= '7')
                        && (i3 >= '0' && i3 <= '7')) {
                    byte bVal = (byte) ((i3 - '0') + ((i2 - '0') * 8) + ((i1 - '0') * 8 * 8));
                    byte[] bValArr = new byte[1];
                    bValArr[0] = bVal;
                    String tmp = new String(bValArr);
                    sb.append(tmp);
                    i += 3;
                    continue;
                }
            }

            if (currentChar == '\\' && (i + 2 < b.length())) {
                char n = b.charAt(i + 1);
                switch (n) {
                    case '0':
                        sb.append("\0");
                        break;
                    case '\'':
                        sb.append("'");
                        break;
                    case '"':
                        sb.append("\"");
                        break;
                    case 'b':
                        sb.append("\b");
                        break;
                    case 'n':
                        sb.append("\n");
                        break;
                    case 'r':
                        sb.append("\r");
                        break;
                    case 't':
                        sb.append("\t");
                        break;
                    case 'Z':
                        sb.append("\u001A");
                        break;
                    case '\\':
                        sb.append("\\");
                        break;
                        // The following 2 lines are exactly what MySQL does TODO: why do we do
                        // this?
                    case '%':
                        sb.append("\\%");
                        break;
                    case '_':
                        sb.append("\\_");
                        break;
                    default:
                        sb.append(n);
                }
                i++;
            } else {
                sb.append(currentChar);
            }
        }
        return sb.toString();
    }