Case - class from required module is not available

[Alexey Fedorov]

Hello!

Suppose we have simple construction with 4 modules:

****************************************

module a @ 1.0 {
}

****************************************

module b @ 1.0 {
     requires optional a@<1.0;
     exports b;
}

package b;
public class B {
}

****************************************

module c @ 1.0 {
     requires optional a;
     requires b;

     exports c;
     class c.C;
}

package c;
public class C {
     public static void main(String[] args) {
         try {
             Class bClazz = Class.forName("b.B");
             System.out.println(bClazz + " is AVAILABLE from c.C!");
         } catch (ClassNotFoundException e) {
             System.out.println("b.B is NOT AVAILABLE from c.C!");
         }
     }
}

****************************************

module d @ 1.0 {
     requires optional a;
     requires optional b;

     exports d;
     class d.D;
}

package d;
public class D {
     public static void main(String[] args) {
         try {
             Class bClazz = Class.forName("b.B");
             System.out.println(bClazz + " is AVAILABLE from d.D!");
         } catch (ClassNotFoundException e) {
             System.out.println("b.B is NOT AVAILABLE from d.D!");
         }
     }
}

****************************************

Running c.C and d.D in sequence shows:

> class b.B is AVAILABLE from c.C!
> class b.B is NOT AVAILABLE from d.D!

and it seems very strange for me. Could you please clarify, why class 
b.B is not available from d.D?

--
Alexey