I have been engaged in Android development for many years, and I feel that Android has been changing. As a user, you can feel the many new functions brought about by changes;
as a developer, you can appreciate how fast knowledge is changing .
I don't remember which philosopher said: The only constant is change. I think this sentence is very suitable for Android.
In addition, from this year's Google Developers Conference, we can see that Google is vigorously promoting Jetpack and Kotlin. If this continues, it is estimated that there will be no Java in the App in the future, and there will be less and less Java in the Framework.