Issue with arrow-c JNI and GraalVM 25 #866

Describe the enhancement requested

I'm aware that graalvm is probably not supported, but I'm raising this as it might be simple fix.

There is a issue with env->FindClass in arrow-c when used with graalvm 25 (native image creates a shared library) Even all required classes are exposed for JNI in graalvm configuration env->FindClass wont be able to find a classes at

The issues are at:

where class names have L and ; at the start and end of the class name, so changing class names from Ljava/lang/Object; to java/lang/Object (and all other classes) will make problem go away.

kObjectClass = CreateGlobalClassReference(env, "java/lang/Object");
kRuntimeExceptionClass =
    CreateGlobalClassReference(env, "java/lang/RuntimeException");
kPrivateDataClass =
    CreateGlobalClassReference(env, "org/apache/arrow/c/jni/PrivateData");
kCDataExceptionClass =
    CreateGlobalClassReference(env, "org/apache/arrow/c/jni/CDataJniException");
kStreamPrivateDataClass = CreateGlobalClassReference(
    env, "org/apache/arrow/c/ArrayStreamExporter$ExportedArrayStreamPrivateData");

looking at the spec,

• https://docs.oracle.com/en/java/javase/11/docs/specs/jni/functions.html#findclass
• https://docs.oracle.com/en/java/javase/21/docs/specs/jni/functions.html#findclass

it says correct format is without L and ';' for non array classes.

I did manage to fix this in 18.1 which could be built locally, unfortunately I can't make 18.3 run locally as instructions at https://arrow.apache.org/docs/developers/java/building.html are outdated with change to new repo

also, one small request, can

return error returned by vm->GetEnv rather than JNI_ERR