flowable/flowable-engine · error · FlowableException

Error converting resource stream

Error message

Error converting resource stream

What it means

When the named resource exists, getDmnDeploymentResourceData streams it via dmnRepositoryService.getResourceAsStream(deploymentId, resourceName) and converts with IOUtils.toByteArray; any failure is wrapped as FlowableException("Error converting resource stream", e). This is an I/O or engine-level failure while reading the resource bytes, not a lookup miss.

Source

Thrown at modules/flowable-dmn-rest/src/main/java/org/flowable/dmn/rest/service/api/repository/BaseDmnDeploymentResourceDataResource.java:75

        DmnDeployment deployment = deploymentQuery.singleResult();
        if (deployment == null) {
            throw new FlowableObjectNotFoundException("Could not find a DMN deployment with id '" + deploymentId);
        }
        
        if (restApiInterceptor != null) {
            restApiInterceptor.accessDeploymentById(deployment);
        }

        List<String> resourceList = dmnRepositoryService.getDeploymentResourceNames(deploymentId);

        if (resourceList.contains(resourceName)) {
            String contentType = contentTypeResolver.resolveContentType(resourceName);
            response.setContentType(contentType);
            try (final InputStream resourceStream = dmnRepositoryService.getResourceAsStream(deploymentId, resourceName)) {
                return IOUtils.toByteArray(resourceStream);
                
            } catch (Exception e) {
                throw new FlowableException("Error converting resource stream", e);
            }
            
        } else {
            // Resource not found in deployment
            throw new FlowableObjectNotFoundException("Could not find a resource with name '" + resourceName + "' in deployment '" + deploymentId);
        }
    }
}

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Inspect and log the chained cause (e.getCause()) to find the underlying SQL/IO failure.
2. Retry the request after verifying database and connection-pool health.
3. If the stored byte array is corrupted, redeploy the DMN deployment to regenerate it.
4. Raise JDBC/network read timeouts for large resources.

Example fix

// before
byte[] data = resourceData.getDmnDeploymentResourceData(deploymentId, name, response); // throws
// after
try {
    byte[] data = resourceData.getDmnDeploymentResourceData(deploymentId, name, response);
} catch (FlowableException e) {
    logger.warn("Stream read failed, cause:", e.getCause());
    data = retry(() -> resourceData.getDmnDeploymentResourceData(deploymentId, name, response), 2);
}

try {
    return client.getDmnDeploymentResourceData(deploymentId, resourceName);
} catch (FlowableException e) {
    logger.warn("cause:", e.getCause());
    return retryWithBackoff(() -> client.getDmnDeploymentResourceData(deploymentId, resourceName), 2);
}

When it happens

Trigger: getResourceAsStream succeeds in lookup but the read/convert fails: DB blob (ACT_GEBYTEARRAY) read error, connection drop mid-stream, IOException from IOUtils.toByteArray, or a FlowableException from the repository service.

Common situations: Transient database outages or pool exhaustion; corrupted byte-array rows after failed/partial deploys or migrations; very large DMN resources hitting read timeouts; network instability between app and DB.

Understand the failure class

Background: "failed to read file", EACCES, ENOENT and "could not read <path>" errors: when a program can't read a file from disk — this error's family across 49 libraries.

Related errors

• Error converting resource stream
• Error converting resource stream
• could not get byte array from resource '${resourceName}'
• Error reading image stream
• Error while reading process diagram image.

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/61d97e2a78e14616. Report an issue: GitHub.