/* * Copyright (c) 2002, 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 4593209 8001667 * @summary Reverse comparator was subtly broken * @author Josh bloch */ import java.util.*; import java.io.*; public class ReverseOrder { static byte[] serialBytes(Object o) { try { ByteArrayOutputStream bos = new ByteArrayOutputStream(); ObjectOutputStream oos = new ObjectOutputStream(bos); oos.writeObject(o); oos.flush(); oos.close(); return bos.toByteArray(); } catch (Throwable t) { throw new Error(t); } } @SuppressWarnings("unchecked") static <T> T serialClone(T o) { try { ObjectInputStream ois = new ObjectInputStream (new ByteArrayInputStream(serialBytes(o))); T clone = (T) ois.readObject(); return clone; } catch (Throwable t) { throw new Error(t); } } public static void main(String[] args) throws Exception { Foo[] a = { new Foo(2), new Foo(3), new Foo(1) }; List list = Arrays.asList(a); Comparator cmp = Collections.reverseOrder(); Collections.sort(list, cmp); Foo[] golden = { new Foo(3), new Foo(2), new Foo(1) }; List goldenList = Arrays.asList(golden); if (!list.equals(goldenList)) throw new Exception(list.toString()); Comparator clone = serialClone(cmp); List list2 = Arrays.asList(a); Collections.sort(list2, clone); if (!list2.equals(goldenList)) throw new Exception(list.toString()); } } class Foo implements Comparable { int val; Foo(int i) { val = i; } public int compareTo(Object o) { Foo f = (Foo)o; return (val < f.val ? Integer.MIN_VALUE : (val == f.val ? 0 : 1)); } public boolean equals(Object o) { return o instanceof Foo && ((Foo)o).val == val; } public int hashCode() { return val; } public String toString() { return Integer.toString(val); } }