flowable/flowable-engine · error · 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 getVariableData when the requested variable exists but is not a binary/serializable type, so no binary data stream can be produced. Only byte-array and serializable variables have downloadable binary content via this endpoint.

Source

Thrown at modules/flowable-rest/src/main/java/org/flowable/rest/service/api/runtime/process/ExecutionVariableDataResource.java:79

        try {
            byte[] result = null;

            Execution execution = getExecutionFromRequestWithoutAccessCheck(executionId);
            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())) {
                ByteArrayOutputStream buffer = new ByteArrayOutputStream();
                ObjectOutputStream outputStream = new ObjectOutputStream(buffer);
                outputStream.writeObject(variable.getValue());
                outputStream.close();
                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);
        }
    }
}

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Fetch the variable normally (GET .../variables/{variableName}) and read its value instead of the /data endpoint
2. Check the variable's type first (via the variables listing) and only call /data for binary or serializable types
3. Store the value as a byte array or serializable variable if binary retrieval is required
4. Handle the 404-style FlowableObjectNotFoundException response and fall back to the regular variable endpoint

Example fix

// before
GET /runtime/executions/123/variables/status/data
// after
GET /runtime/executions/123/variables/status

const vars = await getExecutionVariables(id);
const v = vars.find(v => v.name === variableName);
const hasBinary = v && (v.type === "binary" || v.type === "serializable");
if (!hasBinary) return await getPlainVariable(id, variableName);

function hasBinaryStream(v) { return v != null && (v.type === "binary" || v.type === "serializable"); }

try { return await fetchVariableData(id, name); }
catch (e) { if (e.status === 404) return await fetchPlainVariable(id, name); throw e; }

When it happens

Trigger: GET /runtime/executions/{executionId}/variables/{variableName}/data where the variable's type is a plain primitive (string, integer, boolean, date, etc.) rather than a binary or serializable variable.

Common situations: Clients assuming all variables have a binary data endpoint, requesting /data for a variable stored as a JSON string, scripts that fetch all variables' data uniformly without checking variable type first.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

• The variable does not have a binary data stream.
• Variable '${restVariable.getName()}' has unsupported type: '
• Invalid variable scope: '${scope}'
• The variable does not have a binary data stream.
• Unexpected exception getting variable data

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/76c2daeb7c23d285. Report an issue: GitHub.