Creating a new instance of a member class?

Question

I'm writting a serialization library for a college project and I have a problem with deserializing an object which class contains a member class. A rough example:
class Outer{
     class Member{
          double d =0;
     public Member member =new Member();     
}Most basically I tried to get a new instance of the Member class in order to get the double field, change it's value, then use that new instance as a field of an object of the Outer class.
Field f = Outer.class.getDeclaredField("member");
f.setAccessible(true);
f.getClass().newInstance(); Both this and the Constructor method throw an exception:
Exception in thread "main" java.lang.InstantiationException: java.lang.reflect.Fieldpointing at the line with newInstance().
Is there anything I can do to create an object of a member class? And if not then taking into account that I have to deserialize the Outer object from an XML file what could be the alternative?

Answer 1

The error message already gives you a hint that it's not class Outer.Member you're instantiating there (review the API docs)...
import java.lang.reflect.*;
public class Outer{
  public static void main(final String[] args) {
    final Field f = Outer.class.getDeclaredField("member");
    f.setAccessible(true);
    final Constructor ctor =
            f.getType().getDeclaredConstructor(new Class[] { Outer.class });
    final Object outer = new Outer();
    final Object member = ctor.newInstance(new Object[] { outer });
    // set member.d
    f.set(outer, member);
  class Member{
    double d =0;
  public Member member =new Member();     
}