flowable/flowable-engine · error · FlowableIllegalArgumentException

variable name is null

Error message

variable name is null

What it means

Thrown by SetVariableCmd.execute when variableName is null. The command validates arguments before loading the case instance; a null name cannot be stored as a variable and is rejected with FlowableIllegalArgumentException.

Source

Thrown at modules/flowable-cmmn-engine/src/main/java/org/flowable/cmmn/engine/impl/cmd/SetVariableCmd.java:51

public class SetVariableCmd implements Command<Void> {
    
    protected String caseInstanceId;
    protected String variableName;
    protected Object variableValue;
    
    public SetVariableCmd(String caseInstanceId, String variableName, Object variableValue) {
        this.caseInstanceId = caseInstanceId;
        this.variableName = variableName;
        this.variableValue = variableValue;
    }
    
    @Override
    public Void execute(CommandContext commandContext) {
        if (caseInstanceId == null) {
            throw new FlowableIllegalArgumentException("caseInstanceId is null");
        }
        if (variableName == null) {
            throw new FlowableIllegalArgumentException("variable name is null");
        }
     
        CaseInstanceEntity caseInstanceEntity = CommandContextUtil.getCaseInstanceEntityManager(commandContext).findById(caseInstanceId);
        if (caseInstanceEntity == null) {
            throw new FlowableObjectNotFoundException("No case instance found for id " + caseInstanceId, CaseInstanceEntity.class);
        }
        caseInstanceEntity.setVariable(variableName, variableValue);
        
        CmmnEngineAgenda agenda = CommandContextUtil.getAgenda(commandContext);
        
        CmmnDeploymentManager deploymentManager = CommandContextUtil.getCmmnEngineConfiguration(commandContext).getDeploymentManager();
        CaseDefinition caseDefinition = deploymentManager.findDeployedCaseDefinitionById(caseInstanceEntity.getCaseDefinitionId());
        boolean evaluateVariableEventListener = false;
        if (caseDefinition != null) {
            CmmnModel cmmnModel = deploymentManager.resolveCaseDefinition(caseDefinition).getCmmnModel();
            for (Case caze : cmmnModel.getCases()) {
                List<VariableEventListener> variableEventListeners = caze.findPlanItemDefinitionsOfType(VariableEventListener.class);
                for (VariableEventListener variableEventListener : variableEventListeners) {

View on GitHub (pinned to d6d39ce1c6)

Solutions

1. Pass a valid non-null variableName
2. Guard the name at the call site before invoking the API
3. Correct the configuration/source that produced null

Example fix

// before
cmmnRuntimeService.setVariable(caseId, name, value);
// after
if (name == null) throw new IllegalArgumentException("variable name required");
cmmnRuntimeService.setVariable(caseId, name, value);

if (variableName == null || variableName.trim().isEmpty()) {
    throw new IllegalArgumentException("variableName must not be null or empty");
}

boolean hasVariableName(String name) { return name != null && !name.trim().isEmpty(); }

try {
    cmmnRuntimeService.setVariable(caseInstanceId, variableName, value);
} catch (FlowableIllegalArgumentException e) {
    log.error("Invalid variable name: {}", e.getMessage());
}

When it happens

Trigger: Calling setVariable(caseInstanceId, null, value), or passing a name computed from data/config that resolved to null.

Common situations: Missing property in configuration, map lookup with absent key, refactoring removed the constant's value.

Related errors

• caseInstanceId is null
• variable name is null
• caseInstanceId is null
• caseInstanceId is null
• variables is null

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/945b1ee0e83746cb. Report an issue: GitHub.