Question

I need to specify the location of some native libraries in my Android application. I was accomplishing this with a hard-coded string:

public static final String DLL_DIR_STR = "/data/data/my.application.package/lib";

but wanted to get the path from Android instead. Following posts like this, I used getDir() to find the lib directory, changing

superCollider = new SCAudio(DLL_DIR_STR);

to

superCollider = new SCAudio(container.$context().getDir("lib", 0).getAbsolutePath());

Oddly, the initial libraries seem to load correctly

Trying to load lib /data/data/my.application.package/lib/libsndfile.so 0x42718d80
Added shared lib /data/data/my.application.package/lib/libsndfile.so 0x42718d80
No JNI_OnLoad found in /data/data/my.application.package/lib/libsndfile.so 0x42718d80, skipping init
Trying to load lib /data/data/my.application.package/lib/libscsynth.so 0x42718d80
Added shared lib /data/data/my.application.package/lib/libscsynth.so 0x42718d80

But when libscsynth tries to load some additional code, it’s using the wrong path:

OK, listing opendir(/data/data/my.application.package/app_lib)

Any ideas where the “app_” comes from? I thought I must be using getDir() wrong, but the initial files load fine. Could it be something in the native code? Thanks for your help.

Answer 1

I found the answer, quite by accident, in this post. ApplicationInfo.dataDir holds the location of the data directory, and “lib” is easily navigated to from there:

superCollider = new SCAudio(container.$context().getApplicationInfo().dataDir + "/lib");

Alternatively, nativeLibraryDir takes you directly to the lib directory, but requires API level 9.

Thanks for your help!