apache/beam · critical · IllegalStateException

No code generation strategy available

Error message

No code generation strategy available

What it means

ByteBuddy needs a ClassLoadingStrategy to load the generated invoker class. The factory prefers MethodHandles.Lookup.privateLookupIn, then falls back to reflection-based class injection; if neither is available on the JVM it throws this IllegalStateException.

Source

Thrown at sdks/java/core/src/main/java/org/apache/beam/sdk/transforms/reflect/ByteBuddyDoFnInvokerFactory.java:714

            checkStateNotNull(
                methodHandles.getMethod("lookup").invoke(nullObjectForStaticMethodInvocation),
                "'MethodHandles.lookup' declared available, but lookup returned null");

        Method privateLookupIn =
            methodHandles.getMethod(
                "privateLookupIn",
                Class.class,
                Class.forName("java.lang.invoke.MethodHandles$Lookup"));

        Object privateLookup =
            checkStateNotNull(
                privateLookupIn.invoke(nullObjectForStaticMethodInvocation, targetClass, lookup),
                "MethodHandles.Lookup.privateLookupIn not available");
        strategy = ClassLoadingStrategy.UsingLookup.of(privateLookup);
      } else if (ClassInjector.UsingReflection.isAvailable()) {
        strategy = ClassLoadingStrategy.Default.INJECTION;
      } else {
        throw new IllegalStateException("No code generation strategy available");
      }
      return strategy;
    } catch (ReflectiveOperationException e) {
      throw new LinkageError(e.getMessage(), e);
    }
  }

  private static Implementation getRestrictionCoderDelegation(
      TypeDescription doFnType, DoFnSignature signature) {
    if (signature.processElement().isSplittable()) {
      if (signature.getRestrictionCoder() == null) {
        checkStateNotNull(
            signature.getInitialRestriction(),
            "@GetRestrictionCoder provided but @GetInitialRestriction not provided:"
                + " please add @GetInitialRestriction");
        return MethodDelegation.to(
            new DefaultRestrictionCoder(signature.getInitialRestriction().restrictionT()));
      } else {

View on GitHub (pinned to 12126d8942)

Solutions

1. Run on a standard supported JDK (8-17+) where ByteBuddy can use privateLookupIn or reflection injection.
2. Use a runner/execution path that does not rely on runtime bytecode generation, or pre-generate invokers.
3. Upgrade Beam/ByteBuddy to a version supporting your runtime; for native-image, configure substitutions or avoid AOT for this code path.

Example fix

// before
// GraalVM native-image: IllegalStateException: No code generation strategy available
// after
// run on a standard JVM instead of native-image
java -jar app.jar

boolean canGenerate = ClassInjector.UsingReflection.isAvailable();

try {
  invoker = ByteBuddyDoFnInvokerFactory.newByteBuddyInvoker(fn);
} catch (IllegalStateException e) {
  if ("No code generation strategy available".equals(e.getMessage())) {
    throw new UnsupportedOperationException("Runtime requires a JVM with class generation support", e);
  }
  throw e;
}

When it happens

Trigger: Running on a JVM where privateLookupIn is unavailable AND ClassInjector.UsingReflection.isAvailable() returns false — heavily restricted or AOT environments.

Common situations: GraalVM native-image or other AOT compilation where runtime class generation is disabled; exotic JVMs; sandboxed serverless runtimes.

Understand the failure class

Background: "unsupported platform" / "not supported on this platform" errors: what they mean and how to fix them — this error's family across 47 libraries.

Related errors

• Unable to bind invoker for ${fnClass}
• ${e.getMessage()}
• Failed to locate required method ${className}.${methodName}
• Failed to locate ProcessContinuation.stop()
• No code generation strategy available

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/8f0ff426d6b9cb26. Report an issue: GitHub.