How to retrieve session data in service providers in laravel?

I am developing a Laravel project. I am using Laravel 5.1. In my project, I am sharing data to all view in boot method of appServiceProvider in this way.

function boot()
{
    $items = $this->itemRepo->getItems(session("key"));
    view()->share('items', array('items'=>$items));
}

But session value is always null. I saw a lot of article online. But they were not working.So please how can I pass my session value to there ?

via Chebli Mohamed