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  * @compile -source 1.5 SuperfluousAbstract.java
  31  * @run main SuperfluousAbstract
  32  */
  33 
  34 import java.util.AbstractCollection;
  35 import java.util.Collection;
  36 import java.util.Iterator;
  37 
  38 interface Q<E> extends Collection<E> {}
  39 
  40 abstract class AbstractQ<E> extends AbstractCollection<E> implements Q<E> {
  41     // Uncomment this to avoid the AbstractMethodError:
  42     //public abstract Iterator<E> iterator();
  43 }
  44 
  45 class ConcreteQ<E> extends AbstractQ<E> {
  46     public int size() { return 0; }
  47     public Iterator<E> iterator() { return null; }
  48 }
  49 
  50 public class SuperfluousAbstract {
  51     public static void main(String[] args) {
  52         try {
  53             Q<Integer> q = new ConcreteQ<Integer>() ;
  54             for (Integer i : q) {}
  55         }
  56         catch (AbstractMethodError e) {
  57             e.printStackTrace(System.err);
  58         }
  59         catch (NullPointerException e) {
  60             // expected, since iterator() returns null
  61         }
  62     }
  63 }