Java example source code file (Clone.java)

This example Java source code file (Clone.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

clone, linkedlist2, runtimeexception, treemap2, treeset2, util

The Clone.java Java example source code

/*
 * Copyright (c) 1999, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * @test
 * @bug     4216997
 * @summary Cloning a subclass of LinkedList results in an object that isn't
 *          an instance of the subclass.  The same applies to TreeSet and
 *          TreeMap.
 */

import java.util.*;

public class Clone {
    public static void main(String[] args) {
        LinkedList2 l = new LinkedList2();
        LinkedList2 lClone = (LinkedList2) l.clone();
        if (!(l.equals(lClone) && lClone.equals(l)))
            throw new RuntimeException("LinkedList.clone() is broken 1.");
        l.add("a");
        lClone = (LinkedList2) l.clone();
        if (!(l.equals(lClone) && lClone.equals(l)))
            throw new RuntimeException("LinkedList.clone() is broken 2.");
        l.add("b");
        lClone = (LinkedList2) l.clone();
        if (!(l.equals(lClone) && lClone.equals(l)))
            throw new RuntimeException("LinkedList.clone() is broken 2.");


        TreeSet2 s = new TreeSet2();
        TreeSet2 sClone = (TreeSet2) s.clone();
        if (!(s.equals(sClone) && sClone.equals(s)))
            throw new RuntimeException("TreeSet.clone() is broken.");
        s.add("a");
        sClone = (TreeSet2) s.clone();
        if (!(s.equals(sClone) && sClone.equals(s)))
            throw new RuntimeException("TreeSet.clone() is broken.");
        s.add("b");
        sClone = (TreeSet2) s.clone();
        if (!(s.equals(sClone) && sClone.equals(s)))
            throw new RuntimeException("TreeSet.clone() is broken.");

        TreeMap2 m = new TreeMap2();
        TreeMap2 mClone = (TreeMap2) m.clone();
        if (!(m.equals(mClone) && mClone.equals(m)))
            throw new RuntimeException("TreeMap.clone() is broken.");
        m.put("a", "b");
        mClone = (TreeMap2) m.clone();
        if (!(m.equals(mClone) && mClone.equals(m)))
            throw new RuntimeException("TreeMap.clone() is broken.");
        m.put("c", "d");
        mClone = (TreeMap2) m.clone();
        if (!(m.equals(mClone) && mClone.equals(m)))
            throw new RuntimeException("TreeMap.clone() is broken.");
    }

    private static class LinkedList2 extends LinkedList {};
    private static class TreeSet2    extends TreeSet {};
    private static class TreeMap2    extends TreeMap {};
}