quarkusio/quarkus · error · DefinitionException

Decorator declares a producer method: ${decoratorClass}

Error message

Decorator declares a producer method: ${decoratorClass}

What it means

CDI definition error thrown at build time by the ArC processor while validating a decorator class (including its superclasses): a decorator must only decorate via a @Delegate injection point, and a method annotated @Produces turns it into a producer, which the CDI spec forbids inside decorators. The offending class is the decorator named in the message.

Source

Thrown at independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/Decorators.java:164

                    method.appendTo(message);
                    message.append("\n");
                }
                throw new DefinitionException(message.toString());
            }
        }

        checkDecoratorFieldsAndMethods(decoratorClass, beanDeployment);

        return new DecoratorInfo(decoratorClass, beanDeployment, delegateInjectionPoint,
                decoratedTypes, injections, priority);
    }

    private static void checkDecoratorFieldsAndMethods(ClassInfo decoratorClass, BeanDeployment beanDeployment) {
        ClassInfo aClass = decoratorClass;
        while (aClass != null) {
            for (MethodInfo method : aClass.methods()) {
                if (beanDeployment.hasAnnotation(method, DotNames.PRODUCES)) {
                    throw new DefinitionException("Decorator declares a producer method: " + decoratorClass);
                }
                // the following 3 checks rely on the annotation store returning parameter annotations for methods
                if (beanDeployment.hasAnnotation(method, DotNames.DISPOSES)) {
                    throw new DefinitionException("Decorator declares a disposer method: " + decoratorClass);
                }
                if (beanDeployment.hasAnnotation(method, DotNames.OBSERVES)) {
                    throw new DefinitionException("Decorator declares an observer method: " + decoratorClass);
                }
                if (beanDeployment.hasAnnotation(method, DotNames.OBSERVES_ASYNC)) {
                    throw new DefinitionException("Decorator declares an async observer method: " + decoratorClass);
                }
            }

            for (FieldInfo field : aClass.fields()) {
                if (beanDeployment.hasAnnotation(field, DotNames.PRODUCES)) {
                    throw new DefinitionException("Decorator declares a producer field: " + decoratorClass);
                }
            }

View on GitHub (pinned to e1c734241f)

Solutions

1. Remove the @Produces method from the decorator class.
2. Move the producer to a separate non-decorator bean and inject it where needed.
3. If the class should be a producer bean, remove the @Decorator annotation and give it a proper bean-defining annotation.
4. Check superclasses too — the validation walks the hierarchy.

Example fix

// before
@Decorator
public class LoggingGreeting implements Greeter {
    @Produces
    Helper helper() { return new Helper(); }
}

// after
@Decorator
public class LoggingGreeting implements Greeter {
    @Inject Helper helper; // produced elsewhere
}

if (decoratorClass.getAnnotation(jakarta.decorator.Decorator.class) != null)
    for (Method m : decoratorClass.getMethods())
        if (m.isAnnotationPresent(jakarta.enterprise.inject.Produces.class))
            throw new IllegalStateException("Decorator cannot declare producer: " + m);

When it happens

Trigger: A class annotated @Decorator (or inheriting from one) contains a method annotated @Produces, discovered while creating the DecoratorInfo.

Common situations: Converting an ordinary bean that produced helper objects into a decorator without removing producer methods; copy-paste of a producer into a decorator; annotation left behind after refactor.

Related errors

• Decorator declares a producer field: ${decoratorClass}
• Decorator declares a disposer method: ${decoratorClass}
• Decorator declares an observer method: ${decoratorClass}
• Decorator declares an async observer method: ${decoratorClas
• No producer method or field declared by the bean class that

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/3f55e69064a272fc. Report an issue: GitHub.