1 /*
   2  * Copyright (c) 2012 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  * Portions Copyright (c) 2012 IBM Corporation
  26  */
  27 
  28 /*
  29  * @test
  30  * @bug 8000955
  31  * @summary Map.Entry implementations need to comply with Map.Entry.hashCode() defined behaviour.
  32  * @author ngmr
  33  */
  34 import java.util.*;
  35 import java.util.concurrent.ConcurrentHashMap;
  36 import java.util.concurrent.ConcurrentSkipListMap;
  37 
  38 public class EntryHashCode {
  39     private static final int TEST_SIZE = 100;
  40 
  41     static final Object[][] entryData = {
  42         new Object[TEST_SIZE],
  43         new Object[TEST_SIZE]
  44     };
  45 
  46     @SuppressWarnings("unchecked")
  47     static final Map<Object,Object>[] maps = (Map<Object,Object>[])new Map[] {
  48         new HashMap<>(),
  49         new Hashtable<>(),
  50         new IdentityHashMap<>(),
  51         new LinkedHashMap<>(),
  52         new TreeMap<>(),
  53         new WeakHashMap<>(),
  54         new ConcurrentHashMap<>(),
  55         new ConcurrentSkipListMap<>()
  56     };
  57 
  58     static {
  59         for (int i = 0; i < entryData[0].length; i++) {
  60             // key objects need to be Comparable for use in TreeMap
  61             entryData[0][i] = new Comparable<Object>() {
  62                 public int compareTo(Object o) {
  63                     return (hashCode() - o.hashCode());
  64                 }
  65             };
  66             entryData[1][i] = new Object();
  67         }
  68     }
  69 
  70     private static void addTestData(Map<Object,Object> map) {
  71         for (int i = 0; i < entryData[0].length; i++) {
  72             map.put(entryData[0][i], entryData[1][i]);
  73         }
  74     }
  75 
  76     public static void main(String[] args) throws Exception {
  77         Exception failure = null;
  78         for (Map<Object,Object> map: maps) {
  79             addTestData(map);
  80 
  81             try {
  82                 for (Map.Entry<Object,Object> e: map.entrySet()) {
  83                     Object key = e.getKey();
  84                     Object value = e.getValue();
  85                     int expectedEntryHashCode =
  86                         (Objects.hashCode(key) ^ Objects.hashCode(value));
  87 
  88                     if (e.hashCode() != expectedEntryHashCode) {
  89                         throw new Exception("FAILURE: " +
  90                                 e.getClass().getName() +
  91                                 ".hashCode() does not conform to defined" +
  92                                 " behaviour of java.util.Map.Entry.hashCode()");
  93                     }
  94                 }
  95             } catch (Exception e) {
  96                 if (failure == null) {
  97                     failure = e;
  98                 } else {
  99                     failure.addSuppressed(e);
 100                 }
 101             } finally {
 102                 map.clear();
 103             }
 104         }
 105         if (failure != null) {
 106             throw failure;
 107         }
 108     }
 109 }