how could I pass a file path of a local file on my phone to my app (android)?

Issue

I have compiled a C++ shared library using ndk and loaded it successfully from Android Studio but now I have a problem that the interface of my library takes a string as a path to some file as a parameter but I don't know how I should pass this path to my library and where should I put the file on my phone?

Here is how my interface looks like:

public final static native fun(String path);

Solution

Here you go, just make sure you release it when you're done.

JNIEXPORT void JNICALL Java_classes_classes_fun
      (JNIEnv *env, jobject thiz, jstring path){

   const char *nativePath = (*env)->GetStringUTFChars(env, path, 0);

   // use your string as usual

   (*env)->ReleaseStringUTFChars(env, path, nativePath);
}

Also mentioned here: How to get sent string from java code to native C in Android

As for the file handling, you can use the C++ STL libraries.

https://developer.android.com/training/data-storage/files

Describes where you can store files better than I can here.

Answered By - WLGfx