Use 32-bit jni libraries on 64-bit android

问题

I've tried running an application using a native library on the Nexus 9.

The application exits with an error message:

java.lang.UnsatisfiedLinkError: dlopen failed: "lib_xyz.so" is 32-bit instead of 64-bit

Is there any known workaround for this problem (except, of course, recompiling the library and making the apk bigger)?

回答1:

Found an explanation: 64-bit Android can use 32-bit native libraries as a fallback, only if System.loadlLibrary() can't find anything better in the default search path. You get an UnsatisfiedLinkError if you force the system to load the 32-bit library using System.load() with the full library path. So the first workaround is using System.loadLibrary() instead of System.load().

An additional thing that has to be taken into account is that libraries cannot be mixed: the fallback behaviour only applies for the first library your application loads. If the first one is 64-bit, no 32-bit libraries can be loaded by the same application, and vice versa.

回答2:

the point is to convert the run environment to 32 bit

1. add the follow content in build.gradle

   defaultConfig: { ... ndk { abiFilters "armeabi", "armeabi-v7a", "x86", "mips" } }

2. add android.useDeprecatedNdk=true into gradle.properties

3. add new folder named armeabi under the libs, then copy a 32bit .so file into the new folder

回答3:

https://source.android.com/source/64-bit-builds.html

Try this in you Android.mk

LOCAL_MULTILIB := 32

回答4:

Nop, you need to get the native library to be compatible with 64-bit for it to work.

See official documentation: JNI Tips: 64-bit Considerations

回答5:

I encountered the same issue, when I did the update from Android Studio 2.1 to 2.2.3 (with ndk v.13.1), and no tips found in google really helped me (like using abiFilters, exclude 'lib/x86_64/lib….so’, LOCAL_MULTILIB := 32, or TARGET_PREFER_32_BIT := true, …).

Finally, I was able to make it worked again with the latest AS v2.2.3 (without changing anything in Android.mk or in build.gradle), just by using my previous ndk compiler, i.e. android-ndk-r10e

I built the library manually with ndk-build for "armeabi-v7a" and "x86" only, and it worked like a charm on Android with arm64.

回答6:

For me the problem was that I enabled the advanced profiling feature under the build settings of the app

回答7:

This work for me:

 ndk {
        abiFilters 'armeabi-v7a', 'x86'
    }

来源：https://stackoverflow.com/questions/27186243/use-32-bit-jni-libraries-on-64-bit-android