1 /*

     2  * Copyright (c) 2012, 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 import java.util.AbstractCollection;

    24 import java.util.HashSet;

    25 import java.util.AbstractSet;

    26 import java.util.ArrayList;

    27 import java.util.Collection;

    28 import java.util.Iterator;

    29 import java.util.function.Supplier;

    30 

    31 /**

    32  * @library

    33  *

    34  * A simple mutable collection implementation that provides only default

    35  * implementations of all methods. ie. none of the Collection interface default

    36  * methods have overridden implementations.

    37  *

    38  * @param <E> type of collection elements

    39  */

    40 public class ExtendsAbstractCollection<E> extends AbstractCollection<E> {

    41 

    42     protected final Collection<E> coll;

    43 

    44     public ExtendsAbstractCollection() {

    45         this(ArrayList<E>::new);

    46     }

    47 

    48     public ExtendsAbstractCollection(Collection<E> source) {

    49         this();

    50         coll.addAll(source);

    51     }

    52 

    53     protected ExtendsAbstractCollection(Supplier<Collection<E>> backer) {

    54         this.coll = backer.get();

    55     }

    56 

    57     public boolean add(E element) {

    58         return coll.add(element);

    59     }

    60 

    61     public boolean remove(Object element) {

    62         return coll.remove(element);

    63     }

    64 

    65     public Iterator<E> iterator() {

    66         return new Iterator<E>() {

    67             Iterator<E> source = coll.iterator();

    68 

    69             public boolean hasNext() {

    70                 return source.hasNext();

    71             }

    72 

    73             public E next() {

    74                 return source.next();

    75             }

    76 

    77             public void remove() {

    78                 source.remove();

    79             }

    80         };

    81     }

    82 

    83     public int size() {

    84         return coll.size();

    85     }

    86 }