protected int checkNext()

in spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-schedulerx/src/main/java/com/alibaba/cloud/scheduling/schedulerx/util/CronExpression.java [522:659]
128 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;
		}

		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 (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;
		}

		if (c == '-') {
			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() && (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;
					return i;
				}
				else {
					addToSet(val, end, v2, type);
					return i;
				}
			}
			else {
				addToSet(val, end, 1, type);
				return i;
			}
		}

		if (c == '/') {
			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);
			}
		}

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