flowable/flowable-engine · error · FlowableIllegalArgumentException

userId is null

Error message

userId is null

What it means

HistoricCaseInstanceQueryImpl.involvedUser(String userId, String identityLinkType) throws FlowableIllegalArgumentException("userId is null") when the userId parameter is null. This overload filters involvement by a specific identity link type (e.g. participant, owner), and both parameters are required.

Source

Thrown at modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/history/HistoricCaseInstanceQueryImpl.java:1095

    }

    @Override
    public HistoricCaseInstanceQuery involvedUser(String userId) {
        if (userId == null) {
            throw new FlowableIllegalArgumentException("involvedUser is null");
        }
        if (inOrStatement) {
            this.currentOrQueryObject.involvedUser = userId;
        } else {
            this.involvedUser = userId;
        }
        return this;
    }
    
    @Override
    public HistoricCaseInstanceQuery involvedUser(String userId, String identityLinkType) {
        if (userId == null) {
            throw new FlowableIllegalArgumentException("userId is null");
        }
        if (identityLinkType == null) {
            throw new FlowableIllegalArgumentException("identityLinkType is null");
        }
        if (inOrStatement) {
            this.currentOrQueryObject.involvedUserIdentityLink = new IdentityLinkQueryObject(userId, null, identityLinkType);
        } else {
            this.involvedUserIdentityLink = new IdentityLinkQueryObject(userId, null, identityLinkType);
        }
        return this;
    }
    
    @Override
    public HistoricCaseInstanceQuery involvedGroup(String groupId, String identityLinkType) {
        if (groupId == null) {
            throw new FlowableIllegalArgumentException("groupId is null");
        }
        if (identityLinkType == null) {

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Ensure userId is non-null before calling the two-arg involvedUser.
2. If the link type matters but the user is optional, guard the call with a null check.
3. Note the same method also throws "identityLinkType is null" — validate both parameters.
4. Provide sensible defaults (e.g. skip the filter) for anonymous/no-user scenarios.

Example fix

// before
query.involvedUser(userId, IdentityLinkType.PARTICIPANT); // userId may be null
// after
if (userId != null) {
    query.involvedUser(userId, IdentityLinkType.PARTICIPANT);
}

if (userId == null) {
    throw new IllegalArgumentException("userId is required");
}
if (identityLinkType == null) {
    throw new IllegalArgumentException("identityLinkType is required");
}
query.involvedUser(userId, identityLinkType);

boolean canFilterByUserLink(String userId, String type) {
    return userId != null && type != null;
}

try {
    query.involvedUser(userId, identityLinkType);
} catch (FlowableIllegalArgumentException e) {
    if (e.getMessage() != null && e.getMessage().contains("is null")) {
        // skip filter or rethrow with context
    } else {
        throw e;
    }
}

When it happens

Trigger: Calling involvedUser(null, identityLinkType) on a HistoricCaseInstanceQuery; typical when the identity-link-typed variant is chosen but the user id source is null.

Common situations: Refactoring from the single-arg involvedUser to the two-arg version while the user id can still be null; user id comes from a header/claim that is absent; test data omitted the user id.

Related errors

• involvedUser is null
• identityLinkType is null
• groupId is null
• groupIds are null
• variableNames is null or empty

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/7a2e8fc7f2279ded. Report an issue: GitHub.