What is the best way to implement a 3rd party JAR and tie it to blueprints?

So I have this 3rd party JAR that has some functionality I want to implement in the Android version of my game. I have been doing some research and have seen some post about putting it into the …\Engine\Build\Android\Java folder. If that is the case can it be placed in to the project’s Android\APK\libs folder? If not, what is the best way to implement this JAR? Secondly, what is the best way to tie this JAR to a blueprint?
I implemented this JAR in another engine using a Java file that called the functions I needed from the JAR and then a JNI file for the C++ to call the Java functions. Thank you!