alibaba/COLA · error · RuntimeException

execute not supported for natural composite

Error message

execute not supported for natural composite

What it means

NaturalRules is a sequential composite that cannot itself execute facts directly the way a parent composite does; its execute() is intentionally unsupported because it is meant to be the top-level group whose children are driven via doApply, not invoked as an actionable rule. Calling execute() on NaturalRules always throws this RuntimeException.

Solutions

1. Do not call execute() on NaturalRules directly; register it as a top-level rule group and let child rules execute via doApply
2. Use AllRules.and(...) or AnyRules.or(...) for a composite that supports execute() semantics, and keep actions in leaf rules
3. In runners, branch on rule type and skip execute() for NaturalRules

Example fix

// before
NaturalRules group = NaturalRules.natural(ruleA, ruleB);
group.execute(facts); // throws

// after
AllRules.and(ruleA, ruleB).execute(facts); // execut-able composite

if (rule instanceof NaturalRules) {
    // skip execute; drive children through the natural group's own apply path
}

boolean supportsExecute(Object rule) {
    return rule != null && !(rule instanceof NaturalRules);
}

try {
    group.execute(facts);
} catch (RuntimeException e) {
    if (e.getMessage().contains("execute not supported for natural composite")) {
        // use an execut-able composite (AllRules) or leaf rules instead
    } else {
        throw e;
    }
}

When it happens

Trigger: Calling execute(facts) directly on a NaturalRules instance, or a rule runner invoking execute() on every rule including natural composites.

Common situations: Generic engines/loops that uniformly call execute() on all rules; developers assuming all Rule implementations support execute.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

• evaluate not supported for natural composite
• execute not supported for OR relation composite

AI-assisted analysis of alibaba/COLA@352e1a8675 (2026-09-08). Data as JSON: /api/errors/951d58ee09d332ca. Report an issue: GitHub.

Appendix: source

Thrown at cola-components/cola-component-ruleengine/src/main/java/com/alibaba/cola/ruleengine/core/NaturalRules.java:31

public class NaturalRules extends CompositeRule{
    private static final Logger LOGGER = LoggerFactory.getLogger(NaturalRules.class);

    public static CompositeRule of(Rule... rules) {
        CompositeRule instance = new NaturalRules();
        Collections.addAll(instance.rules, rules);
        return instance;
    }

    @Override
    public boolean evaluate(Facts facts) {
        //不支持, which means Natural Rules can not be the children of other rules
        throw new RuntimeException("evaluate not supported for natural composite");
    }

    @Override
    public void execute(Facts facts) {
        //不支持, which means Natural Rules can not be the children of other rules
        throw new RuntimeException("execute not supported for natural composite");
    }

    @Override
    protected boolean doApply(Facts facts) {
        LOGGER.debug("start Natural composite rule apply");
        for (Rule rule : rules) {
            rule.apply(facts);
        }
        return true;
    }
}

View on GitHub (pinned to 352e1a8675)