quarkusio/quarkus · error · IllegalStateException

Injected class not found in index:

Error message

Injected class not found in index: 

What it means

The type of the @CachedResults injection point is not present in the deployment Jandex index. The build step must inspect the class (interface check, constructor check), so an unindexed type — typically from an external jar not indexed by Quarkus — fails the build.

Source

Thrown at extensions/cache/deployment/src/main/java/io/quarkus/cache/deployment/CachedResultsProcessor.java:352

        AnnotationValue excludeValue = annotation.value("exclude");
        if (excludeValue != null)
            exclude = excludeValue.asString();

        if (annotation.target().kind() == Kind.FIELD) {
            type = annotation.target().asField().type();
        } else if (annotation.target().kind() == Kind.METHOD_PARAMETER) {
            type = annotation.target().asMethodParameter().type();
        } else {
            throw new IllegalStateException("Unsupported target:" + annotation.target());
        }

        if (type.kind() != Type.Kind.CLASS) {
            throw new IllegalStateException("Invalid type: " + type);
        }
        ClassInfo injectedClazz = index.getClassByName(type.name());
        if (injectedClazz == null) {
            throw new IllegalStateException("Injected class not found in index: " + type.name());
        }
        if (!injectedClazz.isInterface()
                && !injectedClazz.hasNoArgsConstructor()) {
            throw new IllegalStateException(
                    "@CachedResults class must be an interface or declare a no-args constructor: " + injectedClazz);
        }
        return new CachedResultsInjectConfig(cacheName, lockTimeout, keyGenerator, injectedClazz,
                // consider all but @CachedResults and @Inject
                annotation.target().declaredAnnotations().stream().filter(
                        a -> !a.name().equals(CACHED_RESULTS)
                                && !a.name().equals(INJECT))
                        .toList(),
                exclude);
    }

    record CachedResultsInjectConfig(String cacheName, Long lockTimeout, DotName keyGenerator, ClassInfo injectedClazz,
            Collection<AnnotationInstance> annotations, String exclude) {

View on GitHub (pinned to e1c734241f)

Solutions

1. Add a META-INF/jandex.idx to the library jar, or depend on its `-jandex` classifier artifact if offered.
2. If you control the jar, run the Jandex maven/gradle plugin on it.
3. Ensure the class is actually on the application classpath and spelled correctly.
4. For generated classes, make sure generation happens in a Quarkus-visible source root or via a build step that registers them in the index.

Example fix

<!-- before: external jar with no index -->
<dependency>
  <groupId>com.example</groupId>
  <artifactId>my-api</artifactId>
</dependency>

<!-- after -->
<dependency>
  <groupId>com.example</groupId>
  <artifactId>my-api</artifactId>
  <classifier>jandex</classifier>
</dependency>

// Check the type is on the classpath and indexed
Class<?> clazz = Class.forName("com.example.MyApi");
// If from a library, verify a jandex.idx exists:
// unzip -l my-api.jar | grep 'META-INF/jandex.idx'

When it happens

Trigger: Injecting a type that lives in a dependency jar excluded from the application index (Jandex index), e.g. a class from a non-Quarkus library, or referencing a class produced outside the indexed sources.

Common situations: Third-party interfaces not annotated with @Indexable or shipped in jars without META-INF/jandex.idx; generated classes not visible to the deployment index; typos causing resolution of a non-existent class.

Related errors

• Invalid type:
• Unable to load the datasource driver <driverName> for the <f
• Unable to load the config property type: ${className}
• Unsupported target:
• @CachedResults class must be an interface or declare a no-ar

AI-assisted analysis of quarkusio/quarkus@e1c734241f (2026-09-05). Data as JSON: /api/errors/31ad99c5c70dd46b. Report an issue: GitHub.