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I found an android app in github, it was written by c++ and use the jni. in its jniLibs i only found the "armeabi-v7a" directory, and all the jni files(.so) were Stored here. my android phone cpu architecture is aarch64(arm-v8a), and the app can run fine on my phone. but after i move the SDK in my own app, it always prompts the error

java.lang.UnsatisfiedLinkError: Native library (com/sun/jna/android-aarch64/libjnidispatch.so) not found in resource path (.)

but at the example app when i remove the same '.so' file it says:

java.lang.UnsatisfiedLinkError: Native library (com/sun/jna/android-arm/libjnidispatch.so) not found in resource path (.)

so, what happen？

jeck yung
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1 Answers1

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Typically, an Android device does support multiple ABI's, and 64 bit devices do support native code build for certain 32 bit architectures.

For instance, arm64(64 bit) devices will always also support armeabi-v7a (32bit), to ensure compatibility with older apps. This is a requirement directly from Google.

For instace, to see which architectures your device supports, run:

  • Pre-Lolipop: adb shell getprop ro.product.cpu.abi
  • Lolipop & higher: adb shell getprop ro.product.cpu.abilist

You should see a list of several ABI's as the result of the command.

I have read recently a devblog from Realm in which they tackled some JNI-related issues. One of them was similar to what you're facing.

Their conclusion was that Android gets confused when the same app needs to load 64bit & 32bit native libraries, and only tries to load the 64 bit versions, even if a dependency only has the 32bit version of its native code.

In your case, you try to load a native library build for 32bits, but Android tries to load its 64 bit version. This could happen if one of your other dependencies has 64bit native libraries.

The devblog I mentioned: https://academy.realm.io/posts/kenneth-geisshirt-tales-developing-sdks-at-scale/

Search for "More .so Issues"

Hope this helps

cjurjiu
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