There are could be several issues.
First, you run the sample on unsupported device, like if lib built for armeabi-v7 (and its definitely so due to APP_ABI := armeabi-v7a setting in make file) and your device is intel x86 or lower than 7 armeabi version, etc.
Could be that sample is outdated while lib project has been updated, so some method names was changed or method was removed as deprecated, etc.
Also compiled NDK lib is package sensitive so if you place JNI class into a different package it wont work either.
Also the native library .so-file has to be placed into the right place of your project and its not a libs folder where you place jar-libs usually. Its a bit different folder like as for android studio:
…\src\main\jniLibs\aremabi-v7a\libYourLib.so (for aremabi-v7a version)
…\src\main\jniLibs\x86\libYourLib.so (for x86 version and so on)
UPDATE:
Don’t forget to respect the min API level which is 19. App wont work on devices with lower API level, I mean you could change the min API level in project – don’t do it.
The issue here is that libopenalpr-native.so has a dash - char in its name. Dash is a restricted char for resource naming in AOS. So I replaced it with “_” and app works now
And replace it here as well:
System.loadLibrary("openalpr_native");
And I didn’t use your version of .so but only the included in project one.
UPDATE
Take a look: http://prntscr.com/6w6qfx your lib is just 5kb comparing to original 1.7Mb there is something wrong definitely. And it explains your question in comment:
Why there is no error on System.loadLibrary(“openalpr-native”);? I
just can’t understand this situation – creates libopenalpr-native.so
file, it loads to program, by there is no method.
Could you just use original lib included in sample project instead? Just to test.