Random array is called again when orientation changes in android

I want to display some random sentence in my app. Since that piece of code is inside onCreate method , it is getting called each time the orientation of the app changes.

Here is my code for generating random list of array inside Oncreate method

      int listlen = list.size(); // get the size and gen the random index
     System.out.println("len" + listlen);
     Random indexval = new Random();
    int n = indexval.nextInt(listlen); // get random val
    System.out.println("random num " + n);

I couldn't add this below line of code in my app

    android:configChanges="orientation|screenSize|keyboardHidden"

because I am calculating the screen size manually when orientation changes and also due to some other issues I removed the above line of code. So , is it possible to generate the random list whenever the app opens ? Because I get different random words when orientation changes. Any help would be great !! Thanks