xuxueli/xxl-job · error · ParseException

'L' option is not valid here. (pos={})

Error message

'L' option is not valid here. (pos={})

What it means

In checkNext, when 'L' follows a numeric value in a field that is NOT Day-of-Week, this error fires. The 'NL' syntax (Nth last weekday) is only valid in the day-of-week field. In the main parse loop, standalone 'L' at the start of a field is handled separately (for day-of-month at line 667); this specific path handles 'L' appearing after a digit.

Source

Thrown at xxl-job-admin/src/main/java/com/xxl/job/admin/business/scheduler/cron/CronExpression.java:759

            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) {
                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);
            nearestWeekdays.add(val);
            i++;
            return i;
        }

View on GitHub (pinned to e74c784f68)

Solutions

1. For 'last day of the month' in day-of-month, use standalone 'L' not '15L': '0 0 0 L * ?'.
2. For 'last occurrence of a weekday' in day-of-week, use 'NL' with N in 1-7: '0 0 0 ? * 6L'.
3. Move the 'L' modifier to the correct field.

Example fix

// before
"0 0 0 5L * ?"
// after
"0 0 0 L * ?"

// Reject 'NL' (number followed by L) in any field except day-of-week (index 5)
String[] parts = cron.trim().split("\\s+");
for (int idx = 0; idx < parts.length; idx++) {
    if (parts[idx].matches(".*\\d+L.*") && idx != 5) {
        throw new IllegalArgumentException("'NL' is only valid in day-of-week (field 5): " + parts[idx]);
    }
}

boolean isNumberLInDayOfWeekOnly(String[] parts) {
    for (int idx = 0; idx < parts.length; idx++) {
        if (parts[idx].matches(".*\\d+L.*") && idx != 5) return false;
    }
    return true;

try {
    new CronExpression(cron);
} catch (ParseException e) {
    if (e.getMessage().contains("'L' option is not valid here")) {
        // use standalone 'L' for day-of-month, or move 'NL' to day-of-week
    }
}

When it happens

Trigger: A cron expression like '0 0 0 5L * ?' where '5L' appears in the day-of-month field. The parser reads 5 as a digit, enters checkNext, finds 'L', and since type != DAY_OF_WEEK, throws at line 759.

Common situations: Confusing the day-of-month 'L' (which stands alone as just 'L' or 'L-N') with the day-of-week 'NL' pattern. A developer writes '15L' expecting 'last day' but the parser interprets the digit first.

Related errors

• '?' can only be specified for Day-of-Month -OR- Day-of-Week.
• '/' must be followed by an integer.
• Unexpected end of string.
• 'L' not expected in seconds, minutes or hours fields.
• Offset from last day must be <= {}

AI-assisted analysis of xuxueli/xxl-job@e74c784f68 (2026-08-14). Data as JSON: /api/errors/d096f66ddbb376c2. Report an issue: GitHub.