flowable/flowable-engine · warning · FlowableObjectNotFoundException

The variable does not have a binary data stream.

Error message

The variable does not have a binary data stream.

What it means

FlowableObjectNotFoundException thrown by getVariableDataByteArray when a variable's value is neither a byte array nor a serializable object, so there is no binary data stream to return. The REST variable-data endpoint can only stream content for 'binary' and 'serializable' variable types.

Source

Thrown at modules/flowable-rest/src/main/java/org/flowable/rest/service/api/runtime/process/BaseExecutionVariableResource.java:93

        try {
            byte[] result = null;

            RestVariable variable = getVariableFromRequest(execution, variableName, scope, true);
            if (RestResponseFactory.BYTE_ARRAY_VARIABLE_TYPE.equals(variable.getType())) {
                result = (byte[]) variable.getValue();
                response.setContentType("application/octet-stream");

            } else if (RestResponseFactory.SERIALIZABLE_VARIABLE_TYPE.equals(variable.getType())) {
                try (ByteArrayOutputStream buffer = new ByteArrayOutputStream();
                     ObjectOutputStream outputStream = new ObjectOutputStream(buffer)) {
                    outputStream.writeObject(variable.getValue());
                    result = buffer.toByteArray();
                    response.setContentType("application/x-java-serialized-object");
                }

            } else {
                throw new FlowableObjectNotFoundException("The variable does not have a binary data stream.", null);
            }
            return result;

        } catch (IOException ioe) {
            throw new FlowableException("Error getting variable " + variableName, ioe);
        }
    }

    protected RestVariable setBinaryVariable(MultipartHttpServletRequest request, Execution execution, boolean isNew, boolean async) {

        // Validate input and set defaults
        if (request.getFileMap().size() == 0) {
            throw new FlowableIllegalArgumentException("No file content was found in request body.");
        }

        // Get first file in the map, ignore possible other files
        MultipartFile file = request.getFile(request.getFileMap().keySet().iterator().next());

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Check the variable's type first and only request /data for 'binary' or 'serializable' variables
2. Fetch the variable's value via the normal variable endpoint instead of the data endpoint
3. Catch FlowableObjectNotFoundException and return 404/400 explaining no binary content exists

Example fix

// before
byte[] data = getVariableData(anyVariable); // throws for strings
// after
if ("binary".equals(var.getType()) || "serializable".equals(var.getType())) {
    byte[] data = getVariableData(var);
} else {
    Object value = var.getValue(); // use plain value
}

RestVariable meta = getVariableMetadata(name);
if (!"binary".equals(meta.getType()) && !"serializable".equals(meta.getType())) {
    // fetch plain value via variable endpoint instead
}

boolean hasDownloadableData(RestVariable v) {
    return "binary".equals(v.getType()) || "serializable".equals(v.getType());
}

try {
    byte[] data = client.getVariableData(id);
} catch (NotFoundException e) {
    data = null; // no binary stream for this type
}

When it happens

Trigger: Requesting the data/content of a variable whose type is string, integer, date, etc. (any non-binary type) via the variable data resource.

Common situations: Client assumes every variable has downloadable content; requesting /data on a plain string variable; frontend generic variable-download code that ignores the variable type.

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

• The variable does not have a binary data stream.
• The variable does not have a binary data stream.
• Only string variable values are supported using like, but wa
• Unsupported variable query operation:
• Variable operation is missing for variable:

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/91ff7327bffac0e2. Report an issue: GitHub.