protected int checkNext()

in log4j-core/src/main/java/org/apache/logging/log4j/core/util/CronExpression.java [690:817]
121 lines of code
25 McCabe index (conditional complexity)

    protected int checkNext(final int pos, final String s, final int val, final 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);
            }
            final 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);
            }
            final TreeSet<Integer> set = getSet(type);
            set.add(val);
            i++;
            return i;
        }

        switch (c) {
            case '#':
                if (type != DAY_OF_WEEK) {
                    throw new ParseException("'#' option is not valid here. (pos=" + i + ")", i);
                }
                i++;
                try {
                    nthdayOfWeek = Integers.parseInt(s.substring(i));
                    if (nthdayOfWeek < 1 || nthdayOfWeek > 5) {
                        throw new Exception();
                    }
                } catch (final Exception e) {
                    throw new ParseException("A numeric value between 1 and 5 must follow the '#' option", i);
                }
                final TreeSet<Integer> set = getSet(type);
                set.add(val);
                i++;
                return i;
            case '-':
                i++;
                c = s.charAt(i);
                final 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') {
                    final 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);
                    final 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') {
                        final ValueSet vs = getValue(v2, s, i);
                        final int v3 = vs.value;
                        addToSet(val, end, v3, type);
                        i = vs.pos;
                    } else {
                        addToSet(val, end, v2, type);
                    }
                    return i;
                } else {
                    addToSet(val, end, 1, type);
                    return i;
                }
            case '/':
                i++;
                c = s.charAt(i);
                final 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') {
                    final ValueSet vs = getValue(v2, s, i);
                    final int v3 = vs.value;
                    addToSet(val, end, v3, type);
                    i = vs.pos;
                    return i;
                } else {
                    throw new ParseException("Unexpected character '" + c + "' after '/'", i);
                }
            default:
                break;
        }

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