Using JNA with ReactNative Android App results in "Native Library (com/sun/jna/android-aarch64/libjnidispatch.so" not found in resource path (.)

[Flippy]

I postet my detailed question on stackoverflow:

https://stackoverflow.com/questions/74207214/native-library-com-sun-jna-android-arm-libjnidispatch-so-not-found-in-resource

My problem is when using jna to bridge from c/c++ .so I receive "could not invoke MyCaller.testFunc because libjnidispatch.so not found in resource path (.)"

It neither works if I add the jna.jar file via Android Studio (build.gradle, dependencies{...}) "implementation files('libs/jna-5.12.1.jar')" or if I directly add it with gradle using "implementation 'net.java.dev.jna:jna:5.12.1'".

I also set the source path in android{...} to

SourceSets{

   main {

      jniLibs.srcDirs = ['src/main/jniLibs']

   }

}

I placed the jna.jar inside of android/app/libs and added the missing android-* (e.g. android-aarch64) folder with their libjnidispatch.so. I got the android-aarch64.jar files from the github repository, and changed them to folders.

I also added the android-* folders to android/app/src/main/jniLibs with their full names and only with the architecture (e.g. android-aarch64 and aarch64).

My custom .so file is also located in this folder "android/app/src/main/jniLibs".

Do I have to set any other path?

[Matthias Bläsing]

Hi,

using JNA on android is already covered on stackoverflow:

https://stackoverflow.com/questions/36305914/setting-up-jna-in-android-studio

and in the JNA FAQ:

https://github.com/java-native-access/jna/blob/master/www/FrequentlyAskedQuestions.md#jna-on-android

Hope that helps

Matthias

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[Matthias Bläsing]

Am Freitag, dem 28.10.2022 um 00:25 -0700 schrieb Flippy:
> the @aar trick after implementation files ('libs/jna.5.12.1.jar@aar')
> did the trick for me, thank you!
> Now my library can't be found even if I use
> System.setProperty("jna.library.path", "/absolute/path/to/so")
> and using
> SourceSets main.jniLibs.srcDirs ['src/main/jniLibs'].
>
> I placed my .so to app/src/main/jniLibs/. In this folder I placed the
> .so and I also have folders for each architecture "aarch64" and
> "android-aarch64" consisting the so. Also I placed the all of the
> contents to app/libs.
>
> "Unable to load library 'testlib':
> dlopen failed: library "libtestlib.so" not found
> dlopen failed: library "libtestlib.so" not found
> dlopen failed: library "libtestlib.so" not found
> Native library (android-aarch64/libtestlib.so) not found in resource
> path (.)

This is not a JNA question. Figure out how to properly bundle a native
library on android. On android loading from classpath WILL FAIL. You
have to bundle the native library correctly.

Maybe this:

https://proandroiddev.com/reducing-apk-size-by-using-abi-filters-and-apk-split-74a68a885f4e

and this (see "Include prebuilt native libraries")

https://developer.android.com/studio/projects/gradle-external-native-builds

and this

https://stackoverflow.com/questions/56902428/cant-add-a-so-library-in-android-studio-jnilibs-directory-dont-work

and

https://gist.github.com/TheMobileBridge/d4c831e5c38651f73a9ba92dc4c93cfe

can help

Matthias