apache/seatunnel · error · IllegalArgumentException

The type " + type + " is not supported!

Error message

The type " + type + " is not supported!

What it means

SeaTunnelRowSerializer serializes SeaTunnelRow records into a payload format for SelectDB Cloud load. Only the 'json' and 'csv' formats (case-matched constants) are supported; any other configured value throws this IllegalArgumentException at the first row serialized.

Source

Thrown at seatunnel-connectors-v2/connector-selectdb-cloud/src/main/java/org/apache/seatunnel/connectors/selectdb/serialize/SeaTunnelRowSerializer.java:67

            boolean enableDelete) {
        this.type = type;
        this.seaTunnelRowType = seaTunnelRowType;
        this.fieldDelimiter = fieldDelimiter;
        this.enableDelete = enableDelete;
        if (JSON.equals(type)) {
            objectMapper = new ObjectMapper();
        }
    }

    @Override
    public byte[] serialize(SeaTunnelRow seaTunnelRow) throws IOException {
        String valString;
        if (JSON.equals(type)) {
            valString = buildJsonString(seaTunnelRow);
        } else if (CSV.equals(type)) {
            valString = buildCSVString(seaTunnelRow);
        } else {
            throw new IllegalArgumentException("The type " + type + " is not supported!");
        }
        return valString.getBytes(StandardCharsets.UTF_8);
    }

    public String buildJsonString(SeaTunnelRow row) throws IOException {
        Map<String, Object> rowMap = new HashMap<>(row.getFields().length);

        for (int i = 0; i < row.getFields().length; i++) {
            Object value = convert(seaTunnelRowType.getFieldType(i), row.getField(i));
            rowMap.put(seaTunnelRowType.getFieldName(i), value);
        }
        if (enableDelete) {
            rowMap.put(LoadConstants.DORIS_DELETE_SIGN, parseDeleteSign(row.getRowKind()));
        }
        return objectMapper.writeValueAsString(rowMap);
    }

    public String buildCSVString(SeaTunnelRow row) throws IOException {

View on GitHub (pinned to cf67b549a7)

Solutions

1. Set the sink format option to exactly 'json' or 'csv' (match the constant values in the connector)
2. Check the builder/config code that passes the format string to SeaTunnelRowSerializer and fix the value at the source
3. If another format is genuinely needed, extend serialize() with a new branch and contribute it upstream

Example fix

// before
format = "JSON"; // throws IllegalArgumentException
// after
format = "json"; // matches JSON constant, uses buildJsonString

if (!"json".equals(format) && !"csv".equals(format)) { throw new IllegalArgumentException("format must be json or csv, got: " + format); }

try { serializer.serialize(row); } catch (IllegalArgumentException e) { /* fix config, fail fast at startup */ }

When it happens

Trigger: The sink's serializer format option (seaTunnelRowSerializerBuilder format) is set to a string other than JSON or CSV, e.g. 'parquet' or 'JSON' with different casing than the constants, and serialize() is invoked on the first record.

Common situations: Typo in the format config value; using uppercase 'JSON'/'CSV' when constants compare case-sensitively; copying config from another sink that supports more formats.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

• UNSUPPORTED_DATA_TYPE
• Unsupported type in LocalTimeArrayType: ${eleSqlType}
• Unsupported type: ${sqlType}
• Unsupported type: ${clazz}
• Object to json exception!

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/8cd4fc905d4caa67. Report an issue: GitHub.