Android : Android , Set orientation for entire app in java (include fragments)

I'm checking the size of the device and if it's not tablet I'll set orientation to portrait so I can't set orientation at Manifest. I'm checking the size and orientation at each Activity like this:

if(Services.isMobile()){
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
}

But it has two problems 1.I have to do like so an all activities (and there is a lot of them) 2.It doesn't work for Fragments.