Summary: Use javaClassStatic() for class references stored in static variables - creates global references safe for persistence

findClassLocal() returns a local reference. Storing it in static auto exceptionClass = ... could result in potential 'invalid local reference:'
as local references become invalid when the JNI frame ends

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Author: Github Executorch

extension/android/jni/jni_helper.cpp

@@ -10,13 +10,17 @@
 
 namespace executorch::jni_helper {
 
+// Define the JavaClass wrapper
+struct JExecutorchRuntimeException : public facebook::jni::JavaClass<JExecutorchRuntimeException> {
+  static constexpr auto kJavaDescriptor = "Lorg/pytorch/executorch/ExecutorchRuntimeException;";
+};
+
 void throwExecutorchException(uint32_t errorCode, const std::string& details) {
   // Get the current JNI environment
   auto env = facebook::jni::Environment::current();
 
   // Find the Java ExecutorchRuntimeException class
-  static auto exceptionClass = facebook::jni::findClassLocal(
-      "org/pytorch/executorch/ExecutorchRuntimeException");
+  static const auto exceptionClass = JExecutorchRuntimeException::javaClassStatic();
 
   // Find the static factory method: makeExecutorchException(int, String)
   static auto makeExceptionMethod =