flowable/flowable-engine · error · FlowableIllegalArgumentException

value is null

Error message

value is null

What it means

AbstractVariableQueryImpl.variableValueEqualsIgnoreCase validates its String value argument and throws FlowableIllegalArgumentException("value is null") when null is passed. Case-insensitive equality needs a concrete string to lowercase and compare, so null is rejected up front. The exception is thrown immediately at query-construction time, before the query is executed.

Solutions

1. Check the value for null before calling variableValueEqualsIgnoreCase
2. If an absent value means 'no filter', skip adding the criterion instead of passing null
3. If you truly need null matching, use variableValueEquals/variableValueNotEquals (which support null) rather than the IgnoreCase variant
4. Default the value to a non-null sentinel string if appropriate

Example fix

// before
query.variableValueEqualsIgnoreCase("name", filter.getName()); // NPE-ish if null
// after
if (filter.getName() != null) {
    query.variableValueEqualsIgnoreCase("name", filter.getName());
}

if (name == null || value == null) { throw new IllegalArgumentException("name and value must be non-null"); } query.variableValueEqualsIgnoreCase(name, value);

boolean isNonEmptyString(String s) { return s != null && !s.isEmpty(); }

try { query.variableValueEqualsIgnoreCase(name, value); } catch (FlowableIllegalArgumentException e) { throw new BadRequestException(e.getMessage()); }

When it happens

Trigger: Calling variableValueEqualsIgnoreCase(name, null) (or the localScope variant) on a task/historic/process variable query object.

Common situations: Building queries from user input or optional request parameters where the filter value was never populated; mapping a DTO with a null field directly into the query builder.

Related errors

• Case definition category is null
• Case definition id is null
• Case definition key is null
• name is null
• activatedBefore is null

AI-assisted analysis of flowable/flowable-engine@d6d39ce1c6 (2026-09-11). Data as JSON: /api/errors/ec1bb76a9c80a54e. Report an issue: GitHub.

Appendix: source

Thrown at modules/flowable-variable-service/src/main/java/org/flowable/variable/service/impl/AbstractVariableQueryImpl.java:108

    protected T variableValueEquals(Object value, boolean localScope) {
        queryVariableValues.add(new QueryVariableValue(null, value, QueryOperator.EQUALS, localScope));
        return (T) this;
    }

    @SuppressWarnings("unchecked")
    protected T scopedVariableValueEquals(Object value, String scopeType) {
        queryVariableValues.add(new QueryVariableValue(null, value, QueryOperator.EQUALS, false, scopeType));
        return (T) this;
    }

    public T variableValueEqualsIgnoreCase(String name, String value) {
        return variableValueEqualsIgnoreCase(name, value, true);
    }

    @SuppressWarnings("unchecked")
    protected T variableValueEqualsIgnoreCase(String name, String value, boolean localScope) {
        if (value == null) {
            throw new FlowableIllegalArgumentException("value is null");
        }
        addVariable(name, value.toLowerCase(), QueryOperator.EQUALS_IGNORE_CASE, localScope);
        return (T) this;
    }

    @SuppressWarnings("unchecked")
    protected T scopedVariableValueEqualsIgnoreCase(String name, String value, String scopeType) {
        if (value == null) {
            throw new FlowableIllegalArgumentException("value is null");
        }
        addVariable(name, value.toLowerCase(), QueryOperator.EQUALS_IGNORE_CASE, scopeType, false);
        return (T) this;
    }

    public T variableValueNotEqualsIgnoreCase(String name, String value) {
        return variableValueNotEqualsIgnoreCase(name, value, true);
    }

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