What causes "Provided last name is null" in flowable/flowable-engine?

Pass a concrete non-null last name: userLastName("Smith")

flowable/flowable-engine · error · FlowableIllegalArgumentException

Provided last name is null

Error message

Provided last name is null

What it means

FlowableIllegalArgumentException thrown by UserQueryImpl.userLastName when the lastName argument is null. The engine validates criteria eagerly at query-construction time; a null last name is not a valid equality filter, so it is rejected with a clear message instead of producing invalid SQL. Supply a concrete last-name string.

Solutions

Pass a concrete non-null last name: userLastName("Smith")
Apply the criterion conditionally: if (lastName != null) query.userLastName(lastName)
Use userLastNameLike("%") if you need a wildcard 'any last name' filter rather than null
Sanitize/validate the source field (request param, DTO, profile attribute) before building the query

Example fix

// before
User user = identityService.createUserQuery().userLastName(req.getParameter("lastName")).singleResult();

// after
String lastName = req.getParameter("lastName");
UserQuery query = identityService.createUserQuery();
if (lastName != null) {
    query = query.userLastName(lastName);
}
User user = query.singleResult();

Defensive patterns

Strategy: validation

Validate before calling

if (lastName == null) { throw new IllegalArgumentException("lastName is required"); }
identityService.createUserQuery().userLastName(lastName);

Type guard

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

Try / catch

try {
    query.userLastName(lastName);
} catch (FlowableIllegalArgumentException e) {
    log.warn("Missing last-name criterion: {}", e.getMessage());
}

Prevention

Validate surname input at the entry point (controller/service) before querying
Use conditional chaining for optional criteria
Remember the engine rejects null, not empty strings — still avoid empty filters
Cover nullable profile fields (e.g. from LDAP/SSO sync) with explicit defaults

When it happens

Trigger: Calling identityService.createUserQuery().userLastName(null), or chaining userLastName(value) where value came from a nullable variable, request parameter, or user profile field that was null.

Common situations: User lookup forms with empty surname field; code that assumes a profile field exists but it was never populated; copying values from external systems (SSO/LDAP sync) where last name is optional.

Related errors

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/f54789dd58e480c8. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable-idm-engine/src/main/java/org/flowable/idm/engine/impl/UserQueryImpl.java:123

            throw new FlowableIllegalArgumentException("Provided first name is null");
        }
        this.firstNameLike = firstNameLike;
        return this;
    }

    @Override
    public UserQuery userFirstNameLikeIgnoreCase(String firstNameLikeIgnoreCase) {
        if (firstNameLikeIgnoreCase == null) {
            throw new FlowableIllegalArgumentException("Provided first name is null");
        }
        this.firstNameLikeIgnoreCase = firstNameLikeIgnoreCase.toLowerCase();
        return this;
    }

    @Override
    public UserQuery userLastName(String lastName) {
        if (lastName == null) {
            throw new FlowableIllegalArgumentException("Provided last name is null");
        }
        this.lastName = lastName;
        return this;
    }

    @Override
    public UserQuery userLastNameLike(String lastNameLike) {
        if (lastNameLike == null) {
            throw new FlowableIllegalArgumentException("Provided last name is null");
        }
        this.lastNameLike = lastNameLike;
        return this;
    }

    @Override
    public UserQuery userLastNameLikeIgnoreCase(String lastNameLikeIgnoreCase) {
        if (lastNameLikeIgnoreCase == null) {
            throw new FlowableIllegalArgumentException("Provided last name is null");

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