Name: dbT83986			Date: 01/26/99


Consider this code:

public class Outer implements Cloneable
{
  int i = 5;
  Inner inner1 = new Inner();
  class Inner implements Cloneable
  {
    public String toString()
    {
      return Integer.toString( i );
    }
  }

  public Object clone()
  {
    try
    {
      Outer clone = (Outer) super.clone();
      clone.inner1 = (Inner) inner1.clone();
      return clone;
    }
    catch ( CloneNotSupportedException e )
    {
      throw new Error( "CloneNotSupported: " + e.getMessage() );
    }
  }

  public static void main( String[] args )
  {
    Outer outer1 = new Outer();
    Outer outer2 = (Outer) outer1.clone();
    outer1.i = 8;
    System.out.println( outer1.inner1 + " " + outer2.inner1 );
  }
}

When outer1 is cloned, its clone (outer2) has a
new instance of Inner for its inner1 field, but
this new instance is still considered to be
enclosed by outer1. There is no easy way of making
it part of outer2 instead since outer2 has to
construct inner1 itself in order to enclose it.

Any workarounds (e.g. below) require Inner cloning
to be done manually, and this cloning has to be
updated for changes to Inner fields. This gets
very complicated if Inner is a subclass with an
inheritance hierarchy!!

I don't have any recommendations, but I feel this
situation could be improved. Basically, I think
some way is needed of reattaching a clone of an
inner class to a different enclosing class.
(Review ID: 34066)
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