quarkusio/quarkus · error · DefinitionException

Calling injectInterceptionProxy() more than once is invalid

Error message

Calling injectInterceptionProxy() more than once is invalid

What it means

BeanConfiguratorBase.injectInterceptionProxy() registers an interception proxy for a synthetic bean and must be called at most once per configurator. A second call means the interceptionProxy field is already set, so Arc throws DefinitionException to prevent silently overwriting the interception configuration.

Source

Thrown at independent-projects/arc/processor/src/main/java/io/quarkus/arc/processor/BeanConfiguratorBase.java:428

    /**
     * Declares that this synthetic bean has an injection point of type {@code InterceptionProxy<PT>},
     * where {@code PT} is the {@linkplain #providerType(Type) provider type} of this bean.
     * An instance of {@code PT} may be used as a parameter to {@link InterceptionProxy#create(Object)}
     * in the {@linkplain BeanCreator creator} of this synthetic bean.
     * <p>
     * If the {@code bindingsSource} is not {@code null}, interceptor bindings on the class
     * of the provider type are ignored; instead, the {@code bindingsSource} class is scanned
     * for interceptor binding annotations as defined in {@link io.quarkus.arc.BindingsSource}.
     * <p>
     * This method may only be called once. Subsequent calls throw an exception.
     *
     * @param bindingsSource the bindings source class, may be {@code null}
     * @return self
     */
    public THIS injectInterceptionProxy(DotName bindingsSource) {
        if (interceptionProxy != null) {
            throw new DefinitionException("Calling injectInterceptionProxy() more than once is invalid");
        }
        interceptionProxy = new InterceptionProxyInfo(bindingsSource);
        return self();
    }

    public <U extends T> THIS creator(Class<? extends BeanCreator<U>> creatorClazz) {
        return creator(cg -> {
            BlockCreator bc = cg.createMethod();

            // return new FooBeanCreator().create(syntheticCreationalContext)
            MethodDesc createDesc = MethodDesc.of(BeanCreator.class, "create", Object.class, SyntheticCreationalContext.class);
            bc.return_(bc.invokeInterface(createDesc, bc.new_(creatorClazz), cg.syntheticCreationalContext()));
        });
    }

    /**
     * The first method parameter is the synthetic creational context, i.e. the {@code MethodCreator#getMethodParam(0)} returns
     * a {@link SyntheticCreationalContext} instance that can be used to obtain contextual references for synthetic injection

View on GitHub (pinned to e1c734241f)

Solutions

1. Guard with a flag/check before calling injectInterceptionProxy, or restructure so it's invoked exactly once per configurator
2. If you need different bindings, replace the configurator rather than re-adding — create a new BeanConfigurator
3. Audit extension registrar implementations for duplicate registration of the same synthetic bean

Example fix

// before
config.injectInterceptionProxy(BindingsA.class);
if (extra) config.injectInterceptionProxy(BindingsB.class); // throws
// after
config.injectInterceptionProxy(extra ? BindingsB.class : BindingsA.class);

if (config.interceptionProxyConfigured()) { throw new IllegalStateException("interception proxy already set"); }
config.injectInterceptionProxy(bindingsSource);

try { config.injectInterceptionProxy(src); }
catch (DefinitionException e) { log.error("injectInterceptionProxy called twice on same configurator", e); throw e; }

When it happens

Trigger: Calling beanConfigurator.injectInterceptionProxy(...) twice on the same synthetic bean configurator — typically in shared registrar code paths executed more than once, or two extension registrations both adding an interception proxy to the same bean.

Common situations: Synthetic bean registrars with duplicated/conditional code paths; multiple extensions contributing to the same synthetic bean; copy-paste in an ObserverRegistrar/SyntheticBeanRegistrar.

Related errors

• Unable to find the bean class in the index:
• A synthetic bean ${bean} was defined with invalid scope anno
• The cause of an inactive result must also be inactive
• Creation logic not implemented
• No InterceptionProxy registered for this synthetic bean; cal

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/f836ba174425218c. Report an issue: GitHub.