protected int checkNext()

in client/migrationx/migrationx-domain/migrationx-domain-dataworks/src/main/java/com/aliyun/dataworks/migrationx/domain/dataworks/utils/quartz/CronExpression.java [711:849]
128 lines of code
28 McCabe index (conditional complexity)

    protected int checkNext(int pos, String s, int val, int type)
        throws ParseException {

        int end = -1;
        int i = pos;

        if (i >= s.length()) {
            addToSet(val, end, -1, type);
            return i;
        }

        char c = s.charAt(pos);

        if (c == 'L') {
            if (type == DAY_OF_WEEK) {
                if (val < 1 || val > 7) {
                    throw new ParseException("Day-of-Week values must be between 1 and 7", -1);
                }
                lastdayOfWeek = true;
            } else {
                throw new ParseException("'L' option is not valid here. (pos=" + i + ")", i);
            }
            TreeSet<Integer> set = getSet(type);
            set.add(val);
            i++;
            return i;
        }

        if (c == 'W') {
            if (type == DAY_OF_MONTH) {
                nearestWeekday = true;
            } else {
                throw new ParseException("'W' option is not valid here. (pos=" + i + ")", i);
            }
            if (val > 31) {
                throw new ParseException(
                    "The 'W' option does not make sense with values larger than 31 (max number of days in a month)", i);
            }
            TreeSet<Integer> set = getSet(type);
            set.add(val);
            i++;
            return i;
        }

        if (c == '#') {
            if (type != DAY_OF_WEEK) {
                throw new ParseException("'#' option is not valid here. (pos=" + i + ")", i);
            }
            i++;
            try {
                nthdayOfWeek = Integer.parseInt(s.substring(i));
                if (nthdayOfWeek < 1 || nthdayOfWeek > 5) {
                    throw new Exception();
                }
            } catch (Exception e) {
                throw new ParseException(
                    "A numeric value between 1 and 5 must follow the '#' option",
                    i);
            }

            TreeSet<Integer> set = getSet(type);
            set.add(val);
            i++;
            return i;
        }

        if (c == '-') {
            i++;
            c = s.charAt(i);
            int v = Integer.parseInt(String.valueOf(c));
            end = v;
            i++;
            if (i >= s.length()) {
                addToSet(val, end, 1, type);
                return i;
            }
            c = s.charAt(i);
            if (c >= '0' && c <= '9') {
                ValueSet vs = getValue(v, s, i);
                end = vs.value;
                i = vs.pos;
            }
            if (i < s.length() && ((c = s.charAt(i)) == '/')) {
                i++;
                c = s.charAt(i);
                int v2 = Integer.parseInt(String.valueOf(c));
                i++;
                if (i >= s.length()) {
                    addToSet(val, end, v2, type);
                    return i;
                }
                c = s.charAt(i);
                if (c >= '0' && c <= '9') {
                    ValueSet vs = getValue(v2, s, i);
                    int v3 = vs.value;
                    addToSet(val, end, v3, type);
                    i = vs.pos;
                    return i;
                } else {
                    addToSet(val, end, v2, type);
                    return i;
                }
            } else {
                addToSet(val, end, 1, type);
                return i;
            }
        }

        if (c == '/') {
            if ((i + 1) >= s.length() || s.charAt(i + 1) == ' ' || s.charAt(i + 1) == '\t') {
                throw new ParseException("'/' must be followed by an integer.", i);
            }

            i++;
            c = s.charAt(i);
            int v2 = Integer.parseInt(String.valueOf(c));
            i++;
            if (i >= s.length()) {
                checkIncrementRange(v2, type, i);
                addToSet(val, end, v2, type);
                return i;
            }
            c = s.charAt(i);
            if (c >= '0' && c <= '9') {
                ValueSet vs = getValue(v2, s, i);
                int v3 = vs.value;
                checkIncrementRange(v3, type, i);
                addToSet(val, end, v3, type);
                i = vs.pos;
                return i;
            } else {
                throw new ParseException("Unexpected character '" + c + "' after '/'", i);
            }
        }

        addToSet(val, end, 0, type);
        i++;
        return i;
    }