Q:

Where to find AppCompatPreferenceActivity? 

I am trying android v7 support library and I have this on my gradle file:
compile 'com.android.support:preference-v7:24.2.0'

I am getting class not found error for AppCompatPreferenceActivity. 
I can copy the class from here but am not sure if that is the right way of doing it. 

A:

There is PreferenceActivity (android.preference. PreferenceActivity). 
AppCompatPreferenceActivity is not a part of v7 support library, though it is a part of demos, look into this. 
You can also copy the same from Here.