apache/seatunnel · error · IllegalArgumentException

Illegal format [ ]

Error message

Illegal format [%s]

What it means

DateTimeUtils.parse resolves a Formatter enum by exact match against the user-supplied date-time format string. If the format does not correspond to any supported formatter, it throws IllegalArgumentException 'Illegal format [x]'.

Solutions

1. Use one of the supported formats listed by DateTimeUtils.Formatter enum values
2. Check exact spelling/casing of the configured format string
3. If a new pattern is required, add a Formatter enum entry for it and submit/patch the code

Example fix

// before
datetime_format = "dd/MM/yyyy HH:mm" // unsupported
// after
datetime_format = "yyyy-MM-dd HH:mm:ss"

boolean ok = Arrays.stream(DateTimeUtils.Formatter.values()).anyMatch(f -> f.getValue().equals(userFormat));

try { return DateTimeUtils.parse(value, format); } catch (IllegalArgumentException e) { throw new IllegalArgumentException("Unsupported datetime_format: " + format, e); }

When it happens

Trigger: Calling DateTimeUtils.parse(value, format) with a format string that is not one of the enumerated supported values (e.g. an unsupported pattern instead of 'yyyy-MM-dd HH:mm:ss').

Common situations: Sink/source config uses a datetime_format pattern the parser does not recognize; copied a Java SimpleDateFormat pattern that is not in the Formatter enum; typo or different casing in the configured format.

Related errors

• Illegal format [ ]
• Already an MDCStream
• Already an MDCSupplier
• bucketCount must be greater than zero, but was
• COMMON-33

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/892fc4b00c7a80ce. Report an issue: GitHub.

Appendix: source

Thrown at seatunnel-common/src/main/java/org/apache/seatunnel/common/utils/DateTimeUtils.java:371

        private final String value;

        Formatter(String value) {
            this.value = value;
        }

        public String getValue() {
            return value;
        }

        public static Formatter parse(String format) {
            Formatter[] formatters = Formatter.values();
            for (Formatter formatter : formatters) {
                if (formatter.getValue().equals(format)) {
                    return formatter;
                }
            }
            String errorMsg = String.format("Illegal format [%s]", format);
            throw new IllegalArgumentException(errorMsg);
        }
    }
}

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