flowable/flowable-engine · error · FlowableException

Error converting resource stream

Error message

Error converting resource stream

What it means

Thrown by AppDefinitionResourceDataResource.getAppDefinitionResource when the deployed app definition resource exists but reading its byte content from the repository resource stream fails. The library wraps the underlying IOException in a FlowableException with this message. It indicates an I/O problem while converting the resource stream to a byte array, not a missing resource.

Source

Thrown at modules/flowable-app-engine-rest/src/main/java/org/flowable/app/rest/service/api/repository/AppDefinitionResourceDataResource.java:93

        }

        // Check if deployment exists
        AppDeployment deployment = appRepositoryService.createDeploymentQuery().deploymentId(appDefinition.getDeploymentId()).singleResult();
        if (deployment == null) {
            throw new FlowableObjectNotFoundException("Could not find a deployment with id '" + appDefinition.getDeploymentId());
        }

        List<String> resourceList = appRepositoryService.getDeploymentResourceNames(appDefinition.getDeploymentId());

        if (resourceList.contains(appDefinition.getResourceName())) {
            final InputStream resourceStream = appRepositoryService.getResourceAsStream(
                    appDefinition.getDeploymentId(), appDefinition.getResourceName());

            response.setContentType("application/json");
            try {
                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 id '" +
                    appDefinition.getResourceName() + "' in deployment '" + appDefinition.getDeploymentId());
        }
    }
}

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Check the wrapped cause (e.getCause()) in server logs for the real I/O error and fix storage connectivity/corruption.
2. Verify the deployment is intact: redeploy the .app/ZIP artifact.
3. Confirm the DB/filesystem where Flowable stores deployment resources is healthy and has free space.
4. If OOM-related, increase heap or stream the resource instead of loading it fully into a byte array.

Example fix

// before
try {
    return IOUtils.toByteArray(resourceStream);
} catch (Exception e) {
    throw new FlowableException("Error converting resource stream", e);
}
// after
try {
    return IOUtils.toByteArray(resourceStream);
} catch (IOException e) {
    logger.error("Failed reading resource for deployment " + appDefinition.getDeploymentId(), e);
    throw new FlowableException("Error converting resource stream", e);
}

// Verify resource exists before fetching bytes
AppDeploymentResourceResponse r = restTemplate.getForObject(
  "/app-repository/deployments/" + deploymentId + "/resources", AppDeploymentResourceResponse.class);
if (r == null) throw new IllegalStateException("resource missing");

try {
    byte[] data = restTemplate.getForObject(url, byte[].class);
} catch (HttpServerErrorException e) {
    logger.error("Resource stream conversion failed; check cause on server", e);
    throw new IllegalStateException("Resource could not be read from deployment", e);
}

When it happens

Trigger: GET /app-repository/app-definitions/{appDefinitionId}/resource resolves the deployment resource via repositoryService.getResourceAsStream(deploymentId, resourceName), but IOUtils.toByteArray(resourceStream) throws (stream already closed, corrupted deployment store, disk/DB read failure).

Common situations: Database or filesystem backing the deployment store is unreachable or corrupted; resource deleted mid-request; very large resources causing OOM-wrapped read failures.

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
• Unexpected exception getting variable data
• Could not find a resource with id '<resourceName>' in deploy
• <e.getMessage()>
• Could not find an app deployment with id '<deploymentId>

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/3131580ef55d1e46. Report an issue: GitHub.