apache/seatunnel · error · java.lang.IllegalArgumentException

Json parsing exception.

Error message

Json parsing exception.

What it means

ExcelReadStrategy.readByPoi opens a POI Workbook based on the current file's extension: .xls becomes HSSFWorkbook and .xlsx becomes XSSFWorkbook. Any other extension falls into the else branch and throws FileConnectorException with UNSUPPORTED_OPERATION, because the POI code path only knows how to read real Excel files.

Source

Thrown at seatunnel-api/src/main/java/org/apache/seatunnel/api/configuration/ReadonlyConfig.java:61

    /** Stores the concrete key/value pairs of this configuration object. */
    protected final Map<String, Object> confData;

    private ReadonlyConfig(Map<String, Object> confData) {
        this.confData = confData;
    }

    public static ReadonlyConfig fromMap(Map<String, Object> map) {
        return new ReadonlyConfig(map);
    }

    public static ReadonlyConfig fromConfig(Config config) {
        try {
            return fromMap(
                    JACKSON_MAPPER.readValue(
                            config.root().render(ConfigRenderOptions.concise()),
                            new TypeReference<Map<String, Object>>() {}));
        } catch (JsonProcessingException e) {
            throw new IllegalArgumentException("Json parsing exception.", e);
        }
    }

    public <T> T get(Option<T> option) {
        return getOptional(option).orElseGet(option::defaultValue);
    }

    /**
     * Transform to Config todo: This method should be removed after we remove Config
     *
     * @return Config
     * @deprecated Please use ReadonlyConfig directly
     */
    @Deprecated
    public Config toConfig() {
        return ConfigFactory.parseMap(confData);
    }

View on GitHub (pinned to cf67b549a7)

Solutions

1. Ensure every file matched by the source path has an .xls or .xlsx extension.
2. Use the correct file_format for non-Excel files (e.g. text/csv connectors) instead of forcing them through the Excel reader.
3. Rename the file to include a proper .xls/.xlsx extension if it is genuinely an Excel file.

Example fix

// before
path = "/data/export"   // contains export.csv, read with format=excel
// after
path = "/data/export/report.xlsx"   // point at actual .xlsx files

java
String name = new File(path).getName().toLowerCase();
if (!name.endsWith(".xls") && !name.endsWith(".xlsx")) {
    throw new IllegalArgumentException("Excel reader requires .xls/.xlsx, got: " + name);
}

java
static boolean isExcelFile(String path) {
    String n = path == null ? "" : path.toLowerCase();
    return n.endsWith(".xls") || n.endsWith(".xlsx");
}

java
try {
    reader.readProcess(split);
} catch (FileConnectorException e) {
    if (e.getMessage().contains("Only support read excel file")) {
        LOG.error("Path matched non-Excel file; fix path or file_format", e);
    }
}

When it happens

Trigger: readByPoi (invoked from readProcess) is reached while currentFileName does not end with .xls or .xlsx — e.g. the discovery layer matched the file into an Excel source read but the file has a different or missing extension.

Common situations: Pointing a file source with format=excel at a .csv, .et, .xlsb, or extensionless file; files renamed without proper extension; a directory listing that mixes formats; uppercase or mixed-case extensions if the check is case-sensitive on the platform.

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

• prepare method is not supported
• Option not be null.
• Condition option must not be null
• Condition operator must not be null
• Operator %s requires a compareOption (cross-field comparison

AI-assisted analysis of apache/seatunnel@cf67b549a7 (2026-09-10). Data as JSON: /api/errors/cc9681694ed08e2d. Report an issue: GitHub.