JNI: Unable to find field id for 'currentActivity' (static)

Unity Engine
,
1

I am trying to access Java code through C#.
According to what I read Unity - Manual: Create and use plug-ins in Android, there is a object called currentActivity which created by com.unity3d.player

In order to get this object, do I have to attach any files in plugins/android ?

when I try to run those two lines of code:
AndroidJavaClass jc = new AndroidJavaClass(“com.unity3d.player.UnityPlayer”);
AndroidJavaObject jo = jc.GetStatic(“currentActivity”);
I can only find the javaClass jc, jo object cannot be found.

Any comments would be thankful!

2

I just create a empty project, and one single script to test what I posted.