apache/seatunnel · error · UnsupportedOperationException

Unsupported convert to Byte, typeDefine

Error message

Unsupported convert ${value.getClass()} to Byte, typeDefine: ${typeDefine}

What it means

Thrown by BasicDataConverter.convertByte(T typeDefine, Object value) when the value is neither a String nor a Boolean in this dispatch path (Number is handled via a separate overloaded branch). Byte conversion supports string parsing and boolean-to-0/1 mapping; any other class is rejected with the value class and type definition in the message.

Solutions

1. Decode or convert the value first (e.g. byte[0] for byte[], toEpochDay() for LocalDate, numeric parse for strings representing ints)
2. Correct the sink catalog type so it matches the actual source data type
3. Override convertByte(T typeDefine, Object value) in a custom converter to support the reported class

Example fix

// before
byte b = converter.convertByte(typeDefine, row.getField(0)); // byte[] throws
// after
Object v = row.getField(0);
byte b = (v instanceof byte[] && ((byte[]) v).length == 1) ? ((byte[]) v)[0] : converter.convertByte(typeDefine, v);

Object v = row.getField(0);
if (!(v instanceof Number) && !(v instanceof String) && !(v instanceof Boolean)) {
    throw new IllegalArgumentException("Value " + v.getClass() + " is not convertible to BYTE");
}

static boolean isByteConvertible(Object v) {
    return v instanceof Number || v instanceof String || v instanceof Boolean;
}

try {
    b = converter.convertByte(typeDefine, value);
} catch (UnsupportedOperationException e) {
    LOG.warn("Inconvertible value {} for TINYINT: {}", value, e.getMessage());
    b = 0;
}

When it happens

Trigger: Calling convertByte(typeDefine, value) with byte[], LocalDate, Number subclass routed through this branch, Map or other objects while mapping a field to a TINYINT column.

Common situations: A source column typed BINARY/BYTES or DATE is mapped to TINYINT in the sink; nested/struct values reaching scalar converters; catalog definitions changed without updating field extraction.

Understand the failure class

Background: Type mismatch errors: IllegalArgumentException, TypeError and type guards across 150 open-source libraries — this error's family across 150 libraries.

Related errors

• Unsupported convert to Boolean, typeDefine
• Unsupported convert to Boolean
• Unsupported convert to Byte
• Unsupported convert to Float, typeDefine
• Unsupported convert to Float

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/0cc9e78d8deaf528. Report an issue: GitHub.

Appendix: source

Thrown at seatunnel-api/src/main/java/org/apache/seatunnel/api/table/converter/BasicDataConverter.java:1238

    default short convertShort(String value) {
        return Short.parseShort(value);
    }

    default byte convertByte(T typeDefine, Object value) throws UnsupportedOperationException {
        if (value instanceof Byte) {
            return (byte) value;
        }
        if (value instanceof Number) {
            return convertByte(typeDefine, (Number) value);
        }
        if (value instanceof String) {
            return convertByte(typeDefine, (String) value);
        }
        if (value instanceof Boolean) {
            return convertByte(typeDefine, ((boolean) value));
        }
        throw new UnsupportedOperationException(
                "Unsupported convert " + value.getClass() + " to Byte, typeDefine: " + typeDefine);
    }

    default byte convertByte(T typeDefine, Number value) {
        return convertByte(value);
    }

    default byte convertByte(T typeDefine, String value) {
        return convertByte(value);
    }

    default byte convertByte(T typeDefine, boolean value) {
        return convertByte(value);
    }

    default byte convertByte(Object value) throws UnsupportedOperationException {
        if (value instanceof Byte) {
            return (byte) value;

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