thinkphp5.1中构造方法依赖注入

//thinkphp5.1中构造方法依赖注入

class Index{
   protected $user;
   public function __construct(User $user)
   {
       $this->user = $user;
   }

   public function hello()
   {
       return 'Hello,' . $this->user->name ;
   }

}