test/tck/ConcurrentHashMapTest.java

/*
 * Written by members of JCP JSR-166 Expert Group and released to the
 * public domain. Use, modify, and redistribute this code in any way
 * without acknowledgement. Other contributors include Andrew Wright,
 * Jeffrey Hayes, Pat Fischer, Mike Judd.
 */

import junit.framework.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.Enumeration;
import java.io.*;

public class ConcurrentHashMapTest extends JSR166TestCase{
    public static void main(String[] args) {
        junit.textui.TestRunner.run (suite());  
    }
    public static Test suite() {
        return new TestSuite(ConcurrentHashMapTest.class);
    }

    /**
     * Create a map from Integers 1-5 to Strings "A"-"E".
     */
    private static ConcurrentHashMap map5() {   
        ConcurrentHashMap map = new ConcurrentHashMap(5);
        assertTrue(map.isEmpty());
        map.put(one, "A");
        map.put(two, "B");
        map.put(three, "C");
        map.put(four, "D");
        map.put(five, "E");
        assertFalse(map.isEmpty());
        assertEquals(5, map.size());
        return map;
    }

    /**
     *  clear removes all pairs
     */
    public void testClear() {
        ConcurrentHashMap map = map5();
        map.clear();
        assertEquals(map.size(), 0);
    }

    /**
     *  Maps with same contents are equal
     */
    public void testEquals() {
        ConcurrentHashMap map1 = map5();
        ConcurrentHashMap map2 = map5();
        assertEquals(map1, map2);
        assertEquals(map2, map1);
        map1.clear();
        assertFalse(map1.equals(map2));
        assertFalse(map2.equals(map1));
    }

    /**
     *  contains returns true for contained value
     */
    public void testContains() {
        ConcurrentHashMap map = map5();
        assertTrue(map.contains("A"));
        assertFalse(map.contains("Z"));
    }
    
    /**
     *  containsKey returns true for contained key
     */
    public void testContainsKey() {
        ConcurrentHashMap map = map5();
        assertTrue(map.containsKey(one));
        assertFalse(map.containsKey(zero));
    }

    /**
     *  containsValue returns true for held values
     */
    public void testContainsValue() {
        ConcurrentHashMap map = map5();
        assertTrue(map.contains("A"));
        assertFalse(map.contains("Z"));
    }

    /**
     *   enumeration returns an enumeration containing the correct
     *   elements
     */
    public void testEnumeration() {
        ConcurrentHashMap map = map5();
        Enumeration e = map.elements();
        int count = 0;
        while(e.hasMoreElements()){
            count++;
            e.nextElement();
        }
        assertEquals(5, count);
    }

    /**
     *   Clone creates an equal map
     */
    public void testClone() {
        ConcurrentHashMap map = map5();
        ConcurrentHashMap m2 = (ConcurrentHashMap)(map.clone());
        assertEquals(map, m2);
    }

    /**
     *  get returns the correct element at the given key,
     *  or null if not present
     */
    public void testGet() {
        ConcurrentHashMap map = map5();
        assertEquals("A", (String)map.get(one));
        ConcurrentHashMap empty = new ConcurrentHashMap();
        assertNull(map.get("anything"));
    }

    /**
     *  isEmpty is true of empty map and false for non-empty
     */
    public void testIsEmpty() {
        ConcurrentHashMap empty = new ConcurrentHashMap();
        ConcurrentHashMap map = map5();
        assertTrue(empty.isEmpty());
        assertFalse(map.isEmpty());
    }

    /**
     *   keys returns an enumeration containing all the keys from the map
     */
    public void testKeys() {
        ConcurrentHashMap map = map5();
        Enumeration e = map.keys();
        int count = 0;
        while(e.hasMoreElements()){
            count++;
            e.nextElement();
        }
        assertEquals(5, count);
    }

    /**
     *   keySet returns a Set containing all the keys
     */
    public void testKeySet() {
        ConcurrentHashMap map = map5();
        Set s = map.keySet();
        assertEquals(5, s.size());
        assertTrue(s.contains(one));
        assertTrue(s.contains(two));
        assertTrue(s.contains(three));
        assertTrue(s.contains(four));
        assertTrue(s.contains(five));
    }

    /**
     * values collection contains all values
     */
    public void testValues() {
        ConcurrentHashMap map = map5();
        Collection s = map.values();
        assertEquals(5, s.size());
        assertTrue(s.contains("A"));
        assertTrue(s.contains("B"));
        assertTrue(s.contains("C"));
        assertTrue(s.contains("D"));
        assertTrue(s.contains("E"));
    }

    /**
     * entrySet contains all pairs
     */
    public void testEntrySet() {
        ConcurrentHashMap map = map5();
        Set s = map.entrySet();
        assertEquals(5, s.size());
        Iterator it = s.iterator();
        while (it.hasNext()) {
            Map.Entry e = (Map.Entry) it.next();
            assertTrue( 
                       (e.getKey().equals(one) && e.getValue().equals("A")) ||
                       (e.getKey().equals(two) && e.getValue().equals("B")) ||
                       (e.getKey().equals(three) && e.getValue().equals("C")) ||
                       (e.getKey().equals(four) && e.getValue().equals("D")) ||
                       (e.getKey().equals(five) && e.getValue().equals("E")));
        }
    }

    /**
     *   putAll  adds all key-value pairs from the given map
     */
    public void testPutAll() {
        ConcurrentHashMap empty = new ConcurrentHashMap();
        ConcurrentHashMap map = map5();
        empty.putAll(map);
        assertEquals(5, empty.size());
        assertTrue(empty.containsKey(one));
        assertTrue(empty.containsKey(two));
        assertTrue(empty.containsKey(three));
        assertTrue(empty.containsKey(four));
        assertTrue(empty.containsKey(five));
    }

    /**
     *   putIfAbsent works when the given key is not present
     */
    public void testPutIfAbsent() {
        ConcurrentHashMap map = map5();
        map.putIfAbsent(new Integer(6), "Z");
        assertTrue(map.containsKey(new Integer(6)));
    }

    /**
     *   putIfAbsent does not add the pair if the key is already present
     */
    public void testPutIfAbsent2() {
        ConcurrentHashMap map = map5();
        assertEquals("A", map.putIfAbsent(one, "Z"));
    }

    /**
     *   remove removes the correct key-value pair from the map
     */
    public void testRemove() {
        ConcurrentHashMap map = map5();
        map.remove(five);
        assertEquals(4, map.size());
        assertFalse(map.containsKey(five));
    }

    /**
     * remove(key,value) removes only if pair present
     */
    public void testRemove2() {
        ConcurrentHashMap map = map5();
        map.remove(five, "E");
        assertEquals(4, map.size());
        assertFalse(map.containsKey(five));
        map.remove(four, "A");
        assertEquals(4, map.size());
        assertTrue(map.containsKey(four));

    }

    /**
     *   size returns the correct values
     */
    public void testSize() {
        ConcurrentHashMap map = map5();
        ConcurrentHashMap empty = new ConcurrentHashMap();
        assertEquals(0, empty.size());
        assertEquals(5, map.size());
    }

    /**
     * toString contains toString of elements
     */
    public void testToString() {
        ConcurrentHashMap map = map5();
        String s = map.toString();
        for (int i = 1; i <= 5; ++i) {
            assertTrue(s.indexOf(String.valueOf(i)) >= 0);
        }
    }        

    // Exception tests
    
    /**
     * Cannot create with negative capacity 
     */
    public void testConstructor1() {
        try {
            new ConcurrentHashMap(-1,0,1);
            shouldThrow();
        } catch(IllegalArgumentException e){}
    }

    /**
     * Cannot create with negative concurrency level
     */
    public void testConstructor2() {
        try {
            new ConcurrentHashMap(1,0,-1);
            shouldThrow();
        } catch(IllegalArgumentException e){}
    }

    /**
     * Cannot create with only negative capacity
     */
    public void testConstructor3() {
        try {
            new ConcurrentHashMap(-1);
            shouldThrow();
        } catch(IllegalArgumentException e){}
    }

    /**
     * get(null) throws NPE
     */
    public void testGet_NullPointerException() {
        try {
            ConcurrentHashMap c = new ConcurrentHashMap(5);
            c.get(null);
            shouldThrow();
        } catch(NullPointerException e){}
    }

    /**
     * containsKey(null) throws NPE
     */
    public void testContainsKey_NullPointerException() {
        try {
            ConcurrentHashMap c = new ConcurrentHashMap(5);
            c.containsKey(null);
            shouldThrow();
        } catch(NullPointerException e){}
    }

    /**
     * containsValue(null) throws NPE
     */
    public void testContainsValue_NullPointerException() {
        try {
            ConcurrentHashMap c = new ConcurrentHashMap(5);
            c.containsValue(null);
            shouldThrow();
        } catch(NullPointerException e){}
    }

    /**
     * contains(null) throws NPE
     */
    public void testContains_NullPointerException() {
        try {
            ConcurrentHashMap c = new ConcurrentHashMap(5);
            c.contains(null);
            shouldThrow();
        } catch(NullPointerException e){}
    }

    /**
     * put(null,x) throws NPE
     */
    public void testPut1_NullPointerException() {
        try {
            ConcurrentHashMap c = new ConcurrentHashMap(5);
            c.put(null, "whatever");
            shouldThrow();
        } catch(NullPointerException e){}
    }

    /**
     * put(x, null) throws NPE
     */
    public void testPut2_NullPointerException() {
        try {
            ConcurrentHashMap c = new ConcurrentHashMap(5);
            c.put("whatever", null);
            shouldThrow();
        } catch(NullPointerException e){}
    }

    /**
     * putIfAbsent(null, x) throws NPE
     */
    public void testPutIfAbsent1_NullPointerException() {
        try {
            ConcurrentHashMap c = new ConcurrentHashMap(5);
            c.putIfAbsent(null, "whatever");
            shouldThrow();
        } catch(NullPointerException e){}
    }

    /**
     * putIfAbsent(x, null) throws NPE
     */
    public void testPutIfAbsent2_NullPointerException() {
        try {
            ConcurrentHashMap c = new ConcurrentHashMap(5);
            c.putIfAbsent("whatever", null);
            shouldThrow();
        } catch(NullPointerException e){}
    }


    /**
     * remove(null) throws NPE
     */
    public void testRemove1_NullPointerException() {
        try {
            ConcurrentHashMap c = new ConcurrentHashMap(5);
            c.put("sadsdf", "asdads");
            c.remove(null);
            shouldThrow();
        } catch(NullPointerException e){}
    }

    /**
     * remove(null, x) throws NPE
     */
    public void testRemove2_NullPointerException() {
        try {
            ConcurrentHashMap c = new ConcurrentHashMap(5);
            c.put("sadsdf", "asdads");
            c.remove(null, "whatever");
            shouldThrow();
        } catch(NullPointerException e){}
    }

    /**
     * A deserialized map equals original
     */
    public void testSerialization() {
        ConcurrentHashMap q = map5();

        try {
            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
            out.writeObject(q);
            out.close();

            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
            ConcurrentHashMap r = (ConcurrentHashMap)in.readObject();
            assertEquals(q.size(), r.size());
            assertTrue(q.equals(r));
            assertTrue(r.equals(q));
        } catch(Exception e){
            e.printStackTrace();
            unexpectedException();
        }
    }


    /**
     * SetValue of an EntrySet entry sets value in the map.
     */
    public void testSetValueWriteThrough() {
        // Adapted from a bug report by Eric Zoerner 
        ConcurrentHashMap map = new ConcurrentHashMap(2, 5.0f, 1);
        assertTrue(map.isEmpty());
        for (int i = 0; i < 20; i++)
            map.put(new Integer(i), new Integer(i));
        assertFalse(map.isEmpty());
        Map.Entry entry1 = (Map.Entry)map.entrySet().iterator().next();
        
        // assert that entry1 is not 16
        assertTrue("entry is 16, test not valid",
                   !entry1.getKey().equals(new Integer(16)));
        
        // remove 16 (a different key) from map 
        // which just happens to cause entry1 to be cloned in map
        map.remove(new Integer(16));
        entry1.setValue("XYZ");
        assertTrue(map.containsValue("XYZ")); // fails
    }
    
}
Revision:	1.6
Committed:	Fri Nov 28 12:38:08 2003 UTC (20 years, 5 months ago) by dl
Branch:	MAIN
Changes since 1.5:	+24 -0 lines
Log Message:	Test EntrySet.entry.setValue
#	Content
1	/*
2	* Written by members of JCP JSR-166 Expert Group and released to the
3	* public domain. Use, modify, and redistribute this code in any way
4	* without acknowledgement. Other contributors include Andrew Wright,
5	* Jeffrey Hayes, Pat Fischer, Mike Judd.
6	*/
7
8	import junit.framework.*;
9	import java.util.*;
10	import java.util.concurrent.*;
11	import java.util.Enumeration;
12	import java.io.*;
13
14	public class ConcurrentHashMapTest extends JSR166TestCase{
15	public static void main(String[] args) {
16	junit.textui.TestRunner.run (suite());
17	}
18	public static Test suite() {
19	return new TestSuite(ConcurrentHashMapTest.class);
20	}
21
22	/**
23	* Create a map from Integers 1-5 to Strings "A"-"E".
24	*/
25	private static ConcurrentHashMap map5() {
26	ConcurrentHashMap map = new ConcurrentHashMap(5);
27	assertTrue(map.isEmpty());
28	map.put(one, "A");
29	map.put(two, "B");
30	map.put(three, "C");
31	map.put(four, "D");
32	map.put(five, "E");
33	assertFalse(map.isEmpty());
34	assertEquals(5, map.size());
35	return map;
36	}
37
38	/**
39	* clear removes all pairs
40	*/
41	public void testClear() {
42	ConcurrentHashMap map = map5();
43	map.clear();
44	assertEquals(map.size(), 0);
45	}
46
47	/**
48	* Maps with same contents are equal
49	*/
50	public void testEquals() {
51	ConcurrentHashMap map1 = map5();
52	ConcurrentHashMap map2 = map5();
53	assertEquals(map1, map2);
54	assertEquals(map2, map1);
55	map1.clear();
56	assertFalse(map1.equals(map2));
57	assertFalse(map2.equals(map1));
58	}
59
60	/**
61	* contains returns true for contained value
62	*/
63	public void testContains() {
64	ConcurrentHashMap map = map5();
65	assertTrue(map.contains("A"));
66	assertFalse(map.contains("Z"));
67	}
68
69	/**
70	* containsKey returns true for contained key
71	*/
72	public void testContainsKey() {
73	ConcurrentHashMap map = map5();
74	assertTrue(map.containsKey(one));
75	assertFalse(map.containsKey(zero));
76	}
77
78	/**
79	* containsValue returns true for held values
80	*/
81	public void testContainsValue() {
82	ConcurrentHashMap map = map5();
83	assertTrue(map.contains("A"));
84	assertFalse(map.contains("Z"));
85	}
86
87	/**
88	* enumeration returns an enumeration containing the correct
89	* elements
90	*/
91	public void testEnumeration() {
92	ConcurrentHashMap map = map5();
93	Enumeration e = map.elements();
94	int count = 0;
95	while(e.hasMoreElements()){
96	count++;
97	e.nextElement();
98	}
99	assertEquals(5, count);
100	}
101
102	/**
103	* Clone creates an equal map
104	*/
105	public void testClone() {
106	ConcurrentHashMap map = map5();
107	ConcurrentHashMap m2 = (ConcurrentHashMap)(map.clone());
108	assertEquals(map, m2);
109	}
110
111	/**
112	* get returns the correct element at the given key,
113	* or null if not present
114	*/
115	public void testGet() {
116	ConcurrentHashMap map = map5();
117	assertEquals("A", (String)map.get(one));
118	ConcurrentHashMap empty = new ConcurrentHashMap();
119	assertNull(map.get("anything"));
120	}
121
122	/**
123	* isEmpty is true of empty map and false for non-empty
124	*/
125	public void testIsEmpty() {
126	ConcurrentHashMap empty = new ConcurrentHashMap();
127	ConcurrentHashMap map = map5();
128	assertTrue(empty.isEmpty());
129	assertFalse(map.isEmpty());
130	}
131
132	/**
133	* keys returns an enumeration containing all the keys from the map
134	*/
135	public void testKeys() {
136	ConcurrentHashMap map = map5();
137	Enumeration e = map.keys();
138	int count = 0;
139	while(e.hasMoreElements()){
140	count++;
141	e.nextElement();
142	}
143	assertEquals(5, count);
144	}
145
146	/**
147	* keySet returns a Set containing all the keys
148	*/
149	public void testKeySet() {
150	ConcurrentHashMap map = map5();
151	Set s = map.keySet();
152	assertEquals(5, s.size());
153	assertTrue(s.contains(one));
154	assertTrue(s.contains(two));
155	assertTrue(s.contains(three));
156	assertTrue(s.contains(four));
157	assertTrue(s.contains(five));
158	}
159
160	/**
161	* values collection contains all values
162	*/
163	public void testValues() {
164	ConcurrentHashMap map = map5();
165	Collection s = map.values();
166	assertEquals(5, s.size());
167	assertTrue(s.contains("A"));
168	assertTrue(s.contains("B"));
169	assertTrue(s.contains("C"));
170	assertTrue(s.contains("D"));
171	assertTrue(s.contains("E"));
172	}
173
174	/**
175	* entrySet contains all pairs
176	*/
177	public void testEntrySet() {
178	ConcurrentHashMap map = map5();
179	Set s = map.entrySet();
180	assertEquals(5, s.size());
181	Iterator it = s.iterator();
182	while (it.hasNext()) {
183	Map.Entry e = (Map.Entry) it.next();
184	assertTrue(
185	(e.getKey().equals(one) && e.getValue().equals("A")) \|\|
186	(e.getKey().equals(two) && e.getValue().equals("B")) \|\|
187	(e.getKey().equals(three) && e.getValue().equals("C")) \|\|
188	(e.getKey().equals(four) && e.getValue().equals("D")) \|\|
189	(e.getKey().equals(five) && e.getValue().equals("E")));
190	}
191	}
192
193	/**
194	* putAll adds all key-value pairs from the given map
195	*/
196	public void testPutAll() {
197	ConcurrentHashMap empty = new ConcurrentHashMap();
198	ConcurrentHashMap map = map5();
199	empty.putAll(map);
200	assertEquals(5, empty.size());
201	assertTrue(empty.containsKey(one));
202	assertTrue(empty.containsKey(two));
203	assertTrue(empty.containsKey(three));
204	assertTrue(empty.containsKey(four));
205	assertTrue(empty.containsKey(five));
206	}
207
208	/**
209	* putIfAbsent works when the given key is not present
210	*/
211	public void testPutIfAbsent() {
212	ConcurrentHashMap map = map5();
213	map.putIfAbsent(new Integer(6), "Z");
214	assertTrue(map.containsKey(new Integer(6)));
215	}
216
217	/**
218	* putIfAbsent does not add the pair if the key is already present
219	*/
220	public void testPutIfAbsent2() {
221	ConcurrentHashMap map = map5();
222	assertEquals("A", map.putIfAbsent(one, "Z"));
223	}
224
225	/**
226	* remove removes the correct key-value pair from the map
227	*/
228	public void testRemove() {
229	ConcurrentHashMap map = map5();
230	map.remove(five);
231	assertEquals(4, map.size());
232	assertFalse(map.containsKey(five));
233	}
234
235	/**
236	* remove(key,value) removes only if pair present
237	*/
238	public void testRemove2() {
239	ConcurrentHashMap map = map5();
240	map.remove(five, "E");
241	assertEquals(4, map.size());
242	assertFalse(map.containsKey(five));
243	map.remove(four, "A");
244	assertEquals(4, map.size());
245	assertTrue(map.containsKey(four));
246
247	}
248
249	/**
250	* size returns the correct values
251	*/
252	public void testSize() {
253	ConcurrentHashMap map = map5();
254	ConcurrentHashMap empty = new ConcurrentHashMap();
255	assertEquals(0, empty.size());
256	assertEquals(5, map.size());
257	}
258
259	/**
260	* toString contains toString of elements
261	*/
262	public void testToString() {
263	ConcurrentHashMap map = map5();
264	String s = map.toString();
265	for (int i = 1; i <= 5; ++i) {
266	assertTrue(s.indexOf(String.valueOf(i)) >= 0);
267	}
268	}
269
270	// Exception tests
271
272	/**
273	* Cannot create with negative capacity
274	*/
275	public void testConstructor1() {
276	try {
277	new ConcurrentHashMap(-1,0,1);
278	shouldThrow();
279	} catch(IllegalArgumentException e){}
280	}
281
282	/**
283	* Cannot create with negative concurrency level
284	*/
285	public void testConstructor2() {
286	try {
287	new ConcurrentHashMap(1,0,-1);
288	shouldThrow();
289	} catch(IllegalArgumentException e){}
290	}
291
292	/**
293	* Cannot create with only negative capacity
294	*/
295	public void testConstructor3() {
296	try {
297	new ConcurrentHashMap(-1);
298	shouldThrow();
299	} catch(IllegalArgumentException e){}
300	}
301
302	/**
303	* get(null) throws NPE
304	*/
305	public void testGet_NullPointerException() {
306	try {
307	ConcurrentHashMap c = new ConcurrentHashMap(5);
308	c.get(null);
309	shouldThrow();
310	} catch(NullPointerException e){}
311	}
312
313	/**
314	* containsKey(null) throws NPE
315	*/
316	public void testContainsKey_NullPointerException() {
317	try {
318	ConcurrentHashMap c = new ConcurrentHashMap(5);
319	c.containsKey(null);
320	shouldThrow();
321	} catch(NullPointerException e){}
322	}
323
324	/**
325	* containsValue(null) throws NPE
326	*/
327	public void testContainsValue_NullPointerException() {
328	try {
329	ConcurrentHashMap c = new ConcurrentHashMap(5);
330	c.containsValue(null);
331	shouldThrow();
332	} catch(NullPointerException e){}
333	}
334
335	/**
336	* contains(null) throws NPE
337	*/
338	public void testContains_NullPointerException() {
339	try {
340	ConcurrentHashMap c = new ConcurrentHashMap(5);
341	c.contains(null);
342	shouldThrow();
343	} catch(NullPointerException e){}
344	}
345
346	/**
347	* put(null,x) throws NPE
348	*/
349	public void testPut1_NullPointerException() {
350	try {
351	ConcurrentHashMap c = new ConcurrentHashMap(5);
352	c.put(null, "whatever");
353	shouldThrow();
354	} catch(NullPointerException e){}
355	}
356
357	/**
358	* put(x, null) throws NPE
359	*/
360	public void testPut2_NullPointerException() {
361	try {
362	ConcurrentHashMap c = new ConcurrentHashMap(5);
363	c.put("whatever", null);
364	shouldThrow();
365	} catch(NullPointerException e){}
366	}
367
368	/**
369	* putIfAbsent(null, x) throws NPE
370	*/
371	public void testPutIfAbsent1_NullPointerException() {
372	try {
373	ConcurrentHashMap c = new ConcurrentHashMap(5);
374	c.putIfAbsent(null, "whatever");
375	shouldThrow();
376	} catch(NullPointerException e){}
377	}
378
379	/**
380	* putIfAbsent(x, null) throws NPE
381	*/
382	public void testPutIfAbsent2_NullPointerException() {
383	try {
384	ConcurrentHashMap c = new ConcurrentHashMap(5);
385	c.putIfAbsent("whatever", null);
386	shouldThrow();
387	} catch(NullPointerException e){}
388	}
389
390
391	/**
392	* remove(null) throws NPE
393	*/
394	public void testRemove1_NullPointerException() {
395	try {
396	ConcurrentHashMap c = new ConcurrentHashMap(5);
397	c.put("sadsdf", "asdads");
398	c.remove(null);
399	shouldThrow();
400	} catch(NullPointerException e){}
401	}
402
403	/**
404	* remove(null, x) throws NPE
405	*/
406	public void testRemove2_NullPointerException() {
407	try {
408	ConcurrentHashMap c = new ConcurrentHashMap(5);
409	c.put("sadsdf", "asdads");
410	c.remove(null, "whatever");
411	shouldThrow();
412	} catch(NullPointerException e){}
413	}
414
415	/**
416	* A deserialized map equals original
417	*/
418	public void testSerialization() {
419	ConcurrentHashMap q = map5();
420
421	try {
422	ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
423	ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
424	out.writeObject(q);
425	out.close();
426
427	ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
428	ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
429	ConcurrentHashMap r = (ConcurrentHashMap)in.readObject();
430	assertEquals(q.size(), r.size());
431	assertTrue(q.equals(r));
432	assertTrue(r.equals(q));
433	} catch(Exception e){
434	e.printStackTrace();
435	unexpectedException();
436	}
437	}
438
439
440	/**
441	* SetValue of an EntrySet entry sets value in the map.
442	*/
443	public void testSetValueWriteThrough() {
444	// Adapted from a bug report by Eric Zoerner
445	ConcurrentHashMap map = new ConcurrentHashMap(2, 5.0f, 1);
446	assertTrue(map.isEmpty());
447	for (int i = 0; i < 20; i++)
448	map.put(new Integer(i), new Integer(i));
449	assertFalse(map.isEmpty());
450	Map.Entry entry1 = (Map.Entry)map.entrySet().iterator().next();
451
452	// assert that entry1 is not 16
453	assertTrue("entry is 16, test not valid",
454	!entry1.getKey().equals(new Integer(16)));
455
456	// remove 16 (a different key) from map
457	// which just happens to cause entry1 to be cloned in map
458	map.remove(new Integer(16));
459	entry1.setValue("XYZ");
460	assertTrue(map.containsValue("XYZ")); // fails
461	}
462
463	}