apache/seatunnel · error · SeaTunnelJsonFormatException

UNSUPPORTED_DATA_TYPE

UNSUPPORTED_DATA_TYPE

Error message

Unsupported type: ${type}

What it means

JsonToRowConverters.createNotNullConverter maps each SeaTunnel data type to a JSON-to-row converter; there is no converter registered for the type being converted, so the switch hits its default branch and throws SeaTunnelJsonFormatException with UNSUPPORTED_DATA_TYPE. This means the row type contains a data type (SqlType) the JSON format cannot deserialize.

Source

Thrown at seatunnel-formats/seatunnel-format-json/src/main/java/org/apache/seatunnel/format/json/JsonToRowConverters.java:217

                    public Object convert(JsonNode jsonNode, String fieldName) {
                        return convertToBigDecimal(jsonNode);
                    }
                };
            case FLOAT_VECTOR:
                return new JsonToObjectConverter() {
                    @Override
                    public Object convert(JsonNode jsonNode, String fieldName) {
                        return convertToFloatVector(jsonNode, fieldName);
                    }
                };
            case ARRAY:
                return createArrayConverter((ArrayType<?, ?>) type);
            case MAP:
                return createMapConverter((MapType<?, ?>) type);
            case ROW:
                return createRowConverter((SeaTunnelRowType) type);
            default:
                throw new SeaTunnelJsonFormatException(
                        CommonErrorCodeDeprecated.UNSUPPORTED_DATA_TYPE,
                        "Unsupported type: " + type);
        }
    }

    private boolean convertToBoolean(JsonNode jsonNode) {
        if (jsonNode.isBoolean()) {
            // avoid redundant toString and parseBoolean, for better performance
            return jsonNode.asBoolean();
        } else {
            return Boolean.parseBoolean(jsonNode.asText().trim());
        }
    }

    private int convertToInt(JsonNode jsonNode) {
        if (jsonNode.canConvertToInt()) {
            // avoid redundant toString and parseInt, for better performance
            return jsonNode.asInt();

View on GitHub (pinned to cf67b549a7)

Solutions

1. Check which field type is unsupported (the message prints it) and change the schema to a JSON-supported type (e.g. STRING, ARRAY<FLOAT>, MAP, ROW).
2. Upgrade seatunnel-format-json / SeaTunnel to a version whose JsonToRowConverters supports the type.
3. If the type is genuinely unsupported, file/patch a converter in JsonToRowConverters.createNotNullConverter.

Example fix

// before
SeaTunnelRowType type = new SeaTunnelRowType(new String[]{"v"}, new SeaTunnelDataType[]{BytesType.INSTANCE}); // unsupported
// after
SeaTunnelRowType type = new SeaTunnelRowType(new String[]{"v"}, new ArrayType<>(FloatType.INSTANCE)); // FLOAT_VECTOR array

for (SeaTunnelDataType<?> t : rowType.getFieldTypes()) {
    switch (t.getSqlType()) {
        case STRING: case BOOLEAN: case TINYINT: case SMALLINT: case INT: case BIGINT:
        case FLOAT: case DOUBLE: case DATE: case TIME: case TIMESTAMP:
        case ARRAY: case MAP: case ROW: case FLOAT_VECTOR:
            break;
        default:
            throw new IllegalArgumentException("JSON format cannot handle type: " + t.getSqlType());
    }
}

static boolean isJsonSupported(SeaTunnelDataType<?> t) {
    switch (t.getSqlType()) {
        case ARRAY: case MAP: case ROW: case FLOAT_VECTOR:
        case STRING: case BOOLEAN: case TINYINT: case SMALLINT: case INT:
        case BIGINT: case FLOAT: case DOUBLE: case DATE: case TIME: case TIMESTAMP:
            return true;
        default:
            return false;
    }
}

try {
    converter = new JsonToRowConverters().createConverter(rowType);
} catch (SeaTunnelJsonFormatException e) {
    throw new IllegalArgumentException("Unsupported field type for JSON format: " + e.getMessage(), e);
}

When it happens

Trigger: A source/sink declares a SeaTunnelRowType whose field type's SqlType falls outside STRING/BOOLEAN/TINYINT..DOUBLE/DATE/TIME/TIMESTAMP/ARRAY/MAP/ROW/FLOAT_VECTOR — e.g. a custom or newly added SqlType, or a BYTES/NULL type — and the JSON deserializer builds converters for it.

Common situations: New data types added to the API but not yet supported by the JSON format (version skew between seatunnel-api and seatunnel-format-json); connectors passing exotic catalog column types into a JSON format schema.

Related errors

• Unsupported type:
• UNSUPPORTED_DATA_TYPE
• Could not find field with name ${fieldName} .
• COMMON-02
• Unsupported SQL type:

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/9f8a83474372b2a6. Report an issue: GitHub.