alibaba/spring-cloud-alibaba · error · ParseException

Unexpected character '{c}' after '/'

Error message

Unexpected character '{c}' after '/'

What it means

Thrown in checkNext after a step '/' when the character following '/' is not a digit (guard at CronExpression.java:639-640). This branch handles steps that appear after a value or a range (e.g. '1-5/x' or '0/x'); a non-digit step is invalid.

Source

Thrown at spring-cloud-alibaba-starters/spring-cloud-starter-alibaba-schedulerx/src/main/java/com/alibaba/cloud/scheduling/schedulerx/util/CronExpression.java:640

		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;
	}

	public String getCronExpression() {
		return cronExpression;
	}

	public String getExpressionSummary() {
		final StringBuilder buf = new StringBuilder();

		buf.append("seconds: ");
		buf.append(getExpressionSetSummary(seconds));
		buf.append("\n");

View on GitHub (pinned to 115d590110)

Solutions

1. Place a digit immediately after '/', e.g. '1-5/x' -> '1-5/2'.
2. Remove the '/' if no step is intended (e.g. '0' alone).
3. Range-check any templated step value.

Example fix

// before
new CronExpression("0 0 0 1-5/x * ?");
// after
new CronExpression("0 0 0 1-5/2 * ?"); // days 1-5 every 2 days

// A '/' must be followed by a digit anywhere in a field.
static boolean allStepsAreNumeric(String cron) {
    if (cron == null) return true;
    for (String f : cron.trim().split("\\s+")) {
        for (int i = 0; i < f.length(); i++) {
            if (f.charAt(i) == '/' && (i + 1 >= f.length() || !Character.isDigit(f.charAt(i + 1))))
                return false;
        }
    }
    return true;
}

try {
    CronExpression cron = new CronExpression(raw);
} catch (ParseException e) {
    throw new IllegalArgumentException("Invalid cron expression: " + raw, e);
}

When it happens

Trigger: `new CronExpression("0 0 0 1-5/x * ?")` ('x' after '/'), or `0 0 0 0/L * ?`, or any '<value>/<non-digit>'.

Common situations: Typo in the step value, a placeholder left as a letter, or a copy-paste that introduced an operator after '/' instead of a number.

Related errors

• '/' must be followed by an integer.
• Unexpected end of string.
• Increment > 60 : {}
• Increment > 24 : {}
• Increment > 31 : {}

AI-assisted analysis of alibaba/spring-cloud-alibaba@115d590110 (2026-08-14). Data as JSON: /api/errors/6015c94434ae0b95. Report an issue: GitHub.