flowable/flowable-engine · error · FlowableIllegalArgumentException

keyLike is null

Error message

keyLike is null

What it means

Fluent-query guard in AppDefinitionQueryImpl.appDefinitionKeyLike: the like-pattern for the app definition key is null, which would otherwise produce a SQL fragment comparing against NULL and silently wrong results.

Source

Thrown at modules/flowable-app-engine/src/main/java/org/flowable/app/engine/impl/repository/AppDefinitionQueryImpl.java:160

            throw new FlowableIllegalArgumentException("ids is an empty collection");
        }
        this.deploymentIds = deploymentIds;
        return this;
    }

    @Override
    public AppDefinitionQueryImpl appDefinitionKey(String key) {
        if (key == null) {
            throw new FlowableIllegalArgumentException("key is null");
        }
        this.key = key;
        return this;
    }

    @Override
    public AppDefinitionQueryImpl appDefinitionKeyLike(String keyLike) {
        if (keyLike == null) {
            throw new FlowableIllegalArgumentException("keyLike is null");
        }
        this.keyLike = keyLike;
        return this;
    }

    @Override
    public AppDefinitionQueryImpl appDefinitionResourceName(String resourceName) {
        if (resourceName == null) {
            throw new FlowableIllegalArgumentException("resourceName is null");
        }
        this.resourceName = resourceName;
        return this;
    }

    @Override
    public AppDefinitionQueryImpl appDefinitionResourceNameLike(String resourceNameLike) {
        if (resourceNameLike == null) {
            throw new FlowableIllegalArgumentException("resourceNameLike is null");

View on GitHub (pinned to d6d39ce1c6)

Solutions

  1. Null-check the pattern; append wildcards only after confirming the base value is non-null
  2. Treat null/empty input as 'no key filter' and skip the call
  3. Catch FlowableIllegalArgumentException at the API layer and return 400

Example fix

// before
query.appDefinitionKeyLike(keyLike + "%");
// after
if (keyLike != null) {
    query.appDefinitionKeyLike(keyLike + "%");
}
Defensive patterns

Strategy: validation

Validate before calling

if (keyLike != null && !keyLike.isEmpty()) {
    query.appDefinitionKeyLike(keyLike);
}

Type guard

boolean isApplicable(String v) { return v != null && !v.isEmpty(); }

Try / catch

try {
    query.appDefinitionKeyLike(keyLike);
} catch (FlowableIllegalArgumentException e) {
    throw new ResponseStatusException(HttpStatus.BAD_REQUEST, e.getMessage(), e);
}

Prevention

When it happens

Trigger: Calling appDefinitionKeyLike(keyLike) with null — usually an optional search term from a request that was not supplied, or a computed pattern (key + "%") where the base key is null.

Common situations: Search UI with an empty key field bound as null; dynamic query builders that always invoke every filter method; pattern built from a nullable configuration value.

Related errors

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/6693ef0be24c2d6e. Report an issue: GitHub.