Class的访问权限

//how to create reference?
class Soup...{
      private Soup()...{}
      public static Soup makeSoup()...{//ths first method:,Allow creation via static mehtod;
                  System.out.println("makeSoup()");
                  return new Soup();
            }
     private static Soup ps1=new Soup();//the second method:Create a  static object and 
     public static Soup access()...{                     //return a reference upon request.
                  System.out.println("access()");
                  return ps1;
            }
     public void f()...{}
}

class Sandwich...{
    void f()...{System.out.println("new Lunch()");new Lunch();}
    }
    
public class Lunch...{
    public static void main(String[] args)...{
        //Soup priv=new Soup(); Can't do this!private constructor
        Soup priv2=Soup.makeSoup();
        Soup priv1=Soup.access();
        Sandwich f1=new Sandwich();
        f1.f();
        }
    }