apache/seatunnel · error · UnsupportedOperationException

Unsupported BYTES value type

Error message

Unsupported BYTES value type: ${value.getClass().getSimpleName()}

What it means

convertToBinary handles BYTES columns accepting byte[], and ByteBuffer; any other object type raises UnsupportedOperationException with the value's simple class name. It exists because TiDB CDC payloads can carry binary data in several container types.

Solutions

1. Check which class the TiDB CDC version emits for binary values and add a branch for it (e.g. decode base64 Strings)
2. Verify column type mapping — a string value in a BYTES slot usually means the schema is wrong
3. Upgrade/align SeaTunnel connector-cdc-tidb and TiDB CDC versions so types agree
4. If base64, decode before handing to the converter

Example fix

// before
} else {
    throw new UnsupportedOperationException(...);
}
// after
} else if (value instanceof String) {
    return Base64.getDecoder().decode((String) value);
} else {
    throw new UnsupportedOperationException(...);
}

static boolean isBytesConvertible(Object v) {
    return v instanceof byte[] || v instanceof ByteBuffer || v instanceof String;
}

static byte[] asBytes(Object v) {
    if (v instanceof byte[]) return (byte[]) v;
    if (v instanceof ByteBuffer) {
        ByteBuffer b = (ByteBuffer) v.duplicate();
        byte[] out = new byte[b.remaining()]; b.get(out); return out;
    }
    if (v instanceof String) return Base64.getDecoder().decode((String) v);
    return null;
}

try {
    return convertToBinary(value);
} catch (UnsupportedOperationException e) {
    log.error("BYTES column got unexpected type {}", value.getClass());
    throw e;
}

When it happens

Trigger: A BLOB/BINARY column whose value arrives as a String, ByteArray, netty ByteBuf, or other non-byte[]/ByteBuffer type inside convert().

Common situations: TiDB CDC emitting binary columns as base64 strings after a version change; schema incorrectly mapped so a VARCHAR value lands in a BYTES column.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• Unsupported BYTES value type:
• Unsupported value type for TIMESTAMP_TZ conversion
• Cannot deserialize TiDB DELETE CDC row because both value…
• Commit row has no matched prewrite row yet, hold it and…
• Fail to deserialize row

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/c6b2b1078ef9b812. Report an issue: GitHub.

Appendix: source

Thrown at seatunnel-connectors-v2/connector-cdc/connector-cdc-tidb/src/main/java/org/apache/seatunnel/connectors/seatunnel/cdc/tidb/source/converter/DefaultDataConverter.java:246

        String[] array = ((String) value).split(",");
        if (array == null) {
            return null;
        }
        return array;
    }

    private static Object convertToBinary(Object value) {
        if (value instanceof byte[]) {
            return value;
        } else if (value instanceof String) {
            return ((String) value).getBytes();
        } else if (value instanceof ByteBuffer) {
            ByteBuffer byteBuffer = (ByteBuffer) value;
            byte[] bytes = new byte[byteBuffer.remaining()];
            byteBuffer.get(bytes);
            return bytes;
        } else {
            throw new UnsupportedOperationException(
                    "Unsupported BYTES value type: " + value.getClass().getSimpleName());
        }
    }

    private static Object convertToString(Object value) {
        if (value instanceof byte[]) {
            return new String((byte[]) value);
        }
        return value;
    }

    private static Object convertToDate(Object value) {
        return TemporalConversions.toLocalDate(value);
    }

    private static Object convertToTime(Object value) {
        if (value instanceof Long) {
            return LocalTime.ofNanoOfDay((Long) value);

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