flowable/flowable-engine · error · FlowableIllegalArgumentException

Description is null

Error message

Description is null

What it means

TaskQueryImpl.taskDescription() rejects a null description with FlowableIllegalArgumentException. Description is an exact-match filter on the task's description column; a null argument cannot express a meaningful equality predicate, so the library fails fast at query-build time instead of producing a broken query.

Solutions

1. Check for null before adding the criterion and skip the filter when absent.
2. Coerce blank input to "" if an exact empty-description match is intended.
3. Make the DTO field default to "" so binding never yields null.
4. Wrap query construction in try-catch on FlowableIllegalArgumentException and surface a validation error.

Example fix

// before
query.taskDescription(criteria.getDescription());
// after
if (criteria.getDescription() != null) {
    query.taskDescription(criteria.getDescription());
}

if (description != null) {
    query.taskDescription(description);
}

boolean isPresent(String s) { return s != null; }

try {
    query.taskDescription(description);
} catch (FlowableIllegalArgumentException e) {
    throw new BadRequestException("description filter must not be null", e);
}

When it happens

Trigger: Calling taskQuery.taskDescription(null) directly, or via dynamic query builders that forward an unset/unbound description field.

Common situations: Search forms where the description box was left blank and the raw value was forwarded; deserialized DTOs missing the description property; code that assumed an empty string would be passed instead of null.

Related errors

• Candidate user is null
• Involved groups are null
• Involved user is null
• Max Priority is null
• Min Priority is null

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/c549d3e8a162f51e. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable-task-service/src/main/java/org/flowable/task/service/impl/TaskQueryImpl.java:351

    @Override
    public TaskQuery taskNameLikeIgnoreCase(String nameLikeIgnoreCase) {
        if (nameLikeIgnoreCase == null) {
            throw new FlowableIllegalArgumentException("Task nameLikeIgnoreCase is null");
        }

        if (orActive) {
            currentOrQueryObject.nameLikeIgnoreCase = nameLikeIgnoreCase.toLowerCase();
        } else {
            this.nameLikeIgnoreCase = nameLikeIgnoreCase.toLowerCase();
        }
        return this;
    }

    @Override
    public TaskQueryImpl taskDescription(String description) {
        if (description == null) {
            throw new FlowableIllegalArgumentException("Description is null");
        }

        if (orActive) {
            currentOrQueryObject.description = description;
        } else {
            this.description = description;
        }
        return this;
    }

    @Override
    public TaskQuery taskDescriptionLike(String descriptionLike) {
        if (descriptionLike == null) {
            throw new FlowableIllegalArgumentException("Task descriptionlike is null");
        }
        if (orActive) {
            currentOrQueryObject.descriptionLike = descriptionLike;
        } else {

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