1 /*
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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
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13  * accompanied this code).
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23 
24 /*
25  * @test
26  * @bug 6585904
27  * @run testng CheckedIdentityMap
28  * @summary Checked collections with underlying maps with identity comparisons
29  */
30 
31 package test.java.util.Collections;
32 
33 import org.testng.annotations.Test;
34 
35 import java.util.IdentityHashMap;
36 import java.util.Map;
37 
38 import static java.util.Collections.checkedMap;
39 import static org.testng.Assert.assertEquals;
40 import static org.testng.Assert.assertNotEquals;
41 
42 public class CheckedIdentityMap {
43 
44     @Test
testHashCode()45     public void testHashCode() {
46         Map<Integer, Integer> m1 = checkedMap(
47             new IdentityHashMap<Integer, Integer>(),
48             Integer.class, Integer.class);
49         Map<Integer, Integer> m2 = checkedMap(
50             new IdentityHashMap<Integer, Integer>(),
51             Integer.class, Integer.class);
52         // NB: these are unique instances. Compare vs. Integer.valueOf(1)
53         m1.put(new Integer(1), new Integer(1));
54         m2.put(new Integer(1), new Integer(1));
55 
56         Map.Entry<Integer, Integer> e1 = m1.entrySet().iterator().next();
57         Map.Entry<Integer, Integer> e2 = m2.entrySet().iterator().next();
58 
59         assertNotEquals(e1, e2);
60         assertEquals(e1.hashCode(), hashCode(e1));
61         assertEquals(e2.hashCode(), hashCode(e2));
62     }
63 
hashCode(Map.Entry<?,?> e)64     static int hashCode(Map.Entry<?,?> e) {
65         return (System.identityHashCode(e.getKey()) ^
66                 System.identityHashCode(e.getValue()));
67     }
68 }
69