Fix Java named actor bug (#9580)

src/ray/core_worker/lib/java/jni_utils.h

@@ -434,6 +434,9 @@ inline jobject NativeRayFunctionDescriptorToJavaStringList(
 
 // Return an actor fullname with job id prepended if this tis a global actor.
 inline std::string GetActorFullName(bool global, std::string name) {
+  if (name.empty()) {
+    return "";
+  }
   return global ? name
                 : ::ray::CoreWorkerProcess::GetCoreWorker().GetCurrentJobId().Hex() + "-" +
                       name;