1 /*
   2  * Copyright 2003 Sun Microsystems, Inc.  All Rights Reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  20  * CA 95054 USA or visit www.sun.com if you need additional information or
  21  * have any questions.
  22  */
  23 
  24 /*
  25  * @test
  26  * @bug 4912795
  27  * @summary AbstractMethodError throws if not redeclare abstract iterator() method
  28  * @author gafter
  29  */
  30 
  31 import java.util.AbstractCollection;
  32 import java.util.Collection;
  33 import java.util.Iterator;
  34 
  35 interface Q<E> extends Collection<E> {}
  36 
  37 abstract class AbstractQ<E> extends AbstractCollection<E> implements Q<E> {
  38     // Uncomment this to avoid the AbstractMethodError:
  39     //public abstract Iterator<E> iterator();
  40 }
  41 
  42 class ConcreteQ<E> extends AbstractQ<E> {
  43     public int size() { return 0; }
  44     public Iterator<E> iterator() { return null; }
  45 }
  46 
  47 public class SuperfluousAbstract {
  48     public static void main(String[] args) {
  49         try {
  50             Q<Integer> q = new ConcreteQ<Integer>() ;
  51             for (Integer i : q) {}
  52         }
  53         catch (AbstractMethodError e) {
  54             e.printStackTrace(System.err);
  55         }
  56         catch (NullPointerException e) {
  57             // expected, since iterator() returns null
  58         }
  59     }
  60 }