How to access non-modified variable : I have a variable that is in a package, where I can neither modify the package or that class and I need to access it is there any way I can do this. I can not modify com.archi.hello or the contents of it

For Example: 

com.archi.hello: 

class obj:

    int j = 123;

com.archi.newpackage:

    int jo;
   
I need to set jo to j without modifying com.archi.hello in any way, and yes i have tried extending the obj. Is there anyway to do this?