>>254
なるほど、こういうことか。知らなかった。252じゃないがサンクス。
public class CloneDemo {
 public static void main(String[] args) throws CloneNotSupportedException {
  CB c1 = new CB();
  c1.x = 10;
  c1.y = 20;
  CB c2 = (CB) c1.clone();
  System.out.println(c2.x);
  System.out.println(c2.y);
 }

 static class CA implements Cloneable{
  int x;
  protected Object clone() throws CloneNotSupportedException {
   CA c1 = (CA) super.clone();
   c1.x = x;
   return c1;
  }
 }

 static class CB extends CA implements Cloneable{
  int y;

  protected Object clone() throws CloneNotSupportedException {
   CB c1 = (CB) super.clone();
   c1.y = y;
   return c1;
  }
 }
}