1 /* 2 * Copyright (c) 2002, 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 24 /* 25 * @test 26 * @bug 4593209 8001667 27 * @summary Reverse comparator was subtly broken 28 * @author Josh bloch 29 */ 30 31 import java.util.*; 32 import java.io.*; 33 34 public class ReverseOrder { 35 static byte[] serialBytes(Object o) { 36 try { 37 ByteArrayOutputStream bos = new ByteArrayOutputStream(); 38 ObjectOutputStream oos = new ObjectOutputStream(bos); 39 oos.writeObject(o); 40 oos.flush(); 41 oos.close(); 42 return bos.toByteArray(); 43 } catch (Throwable t) { 44 throw new Error(t); 45 } 46 } 47 48 @SuppressWarnings("unchecked") 49 static <T> T serialClone(T o) { 50 try { 51 ObjectInputStream ois = new ObjectInputStream 52 (new ByteArrayInputStream(serialBytes(o))); 53 T clone = (T) ois.readObject(); 54 return clone; 55 } catch (Throwable t) { 56 throw new Error(t); 57 } 58 } 59 60 public static void main(String[] args) throws Exception { 61 Foo[] a = { new Foo(2), new Foo(3), new Foo(1) }; 62 List list = Arrays.asList(a); 63 Comparator cmp = Collections.reverseOrder(); 64 Collections.sort(list, cmp); 65 66 Foo[] golden = { new Foo(3), new Foo(2), new Foo(1) }; 67 List goldenList = Arrays.asList(golden); 68 if (!list.equals(goldenList)) 69 throw new Exception(list.toString()); 70 71 Comparator clone = serialClone(cmp); 72 List list2 = Arrays.asList(a); 73 Collections.sort(list2, clone); 74 if (!list2.equals(goldenList)) 75 throw new Exception(list.toString()); 76 } 77 } 78 79 class Foo implements Comparable { 80 int val; 81 Foo(int i) { val = i; } 82 83 public int compareTo(Object o) { 84 Foo f = (Foo)o; 85 return (val < f.val ? Integer.MIN_VALUE : (val == f.val ? 0 : 1)); 86 } 87 88 public boolean equals(Object o) { 89 return o instanceof Foo && ((Foo)o).val == val; 90 } 91 92 public int hashCode() { return val; } 93 94 public String toString() { return Integer.toString(val); } 95 }