test/tck/PriorityQueueTest.java

/*
 * Written by Doug Lea with assistance from members of JCP JSR-166
 * Expert Group and released to the public domain, as explained at
 * http://creativecommons.org/publicdomain/zero/1.0/
 * Other contributors include Andrew Wright, Jeffrey Hayes,
 * Pat Fisher, Mike Judd.
 */

import java.util.Arrays;
import java.util.Collection;
import java.util.Comparator;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.PriorityQueue;
import java.util.Queue;

import junit.framework.Test;
import junit.framework.TestSuite;

public class PriorityQueueTest extends JSR166TestCase {
    public static void main(String[] args) {
        main(suite(), args);
    }
    public static Test suite() {
        return new TestSuite(PriorityQueueTest.class);
    }

    static class MyReverseComparator implements Comparator {
        public int compare(Object x, Object y) {
            return ((Comparable)y).compareTo(x);
        }
    }

    /**
     * Returns a new queue of given size containing consecutive
     * Integers 0 ... n.
     */
    private PriorityQueue<Integer> populatedQueue(int n) {
        PriorityQueue<Integer> q = new PriorityQueue<Integer>(n);
        assertTrue(q.isEmpty());
        for (int i = n - 1; i >= 0; i -= 2)
            assertTrue(q.offer(new Integer(i)));
        for (int i = (n & 1); i < n; i += 2)
            assertTrue(q.offer(new Integer(i)));
        assertFalse(q.isEmpty());
        assertEquals(n, q.size());
        return q;
    }

    /**
     * A new queue has unbounded capacity
     */
    public void testConstructor1() {
        assertEquals(0, new PriorityQueue(SIZE).size());
    }

    /**
     * Constructor throws IAE if capacity argument nonpositive
     */
    public void testConstructor2() {
        try {
            new PriorityQueue(0);
            shouldThrow();
        } catch (IllegalArgumentException success) {}
    }

    /**
     * Initializing from null Collection throws NPE
     */
    public void testConstructor3() {
        try {
            new PriorityQueue((Collection)null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * Initializing from Collection of null elements throws NPE
     */
    public void testConstructor4() {
        try {
            new PriorityQueue(Arrays.asList(new Integer[SIZE]));
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * Initializing from Collection with some null elements throws NPE
     */
    public void testConstructor5() {
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE - 1; ++i)
            ints[i] = new Integer(i);
        try {
            new PriorityQueue(Arrays.asList(ints));
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * Queue contains all elements of collection used to initialize
     */
    public void testConstructor6() {
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE; ++i)
            ints[i] = new Integer(i);
        PriorityQueue q = new PriorityQueue(Arrays.asList(ints));
        for (int i = 0; i < SIZE; ++i)
            assertEquals(ints[i], q.poll());
    }

    /**
     * The comparator used in constructor is used
     */
    public void testConstructor7() {
        MyReverseComparator cmp = new MyReverseComparator();
        PriorityQueue q = new PriorityQueue(SIZE, cmp);
        assertEquals(cmp, q.comparator());
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE; ++i)
            ints[i] = new Integer(i);
        q.addAll(Arrays.asList(ints));
        for (int i = SIZE - 1; i >= 0; --i)
            assertEquals(ints[i], q.poll());
    }

    /**
     * isEmpty is true before add, false after
     */
    public void testEmpty() {
        PriorityQueue q = new PriorityQueue(2);
        assertTrue(q.isEmpty());
        q.add(new Integer(1));
        assertFalse(q.isEmpty());
        q.add(new Integer(2));
        q.remove();
        q.remove();
        assertTrue(q.isEmpty());
    }

    /**
     * size changes when elements added and removed
     */
    public void testSize() {
        PriorityQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(SIZE - i, q.size());
            q.remove();
        }
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.size());
            q.add(new Integer(i));
        }
    }

    /**
     * offer(null) throws NPE
     */
    public void testOfferNull() {
        PriorityQueue q = new PriorityQueue(1);
        try {
            q.offer(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * add(null) throws NPE
     */
    public void testAddNull() {
        PriorityQueue q = new PriorityQueue(1);
        try {
            q.add(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * Offer of comparable element succeeds
     */
    public void testOffer() {
        PriorityQueue q = new PriorityQueue(1);
        assertTrue(q.offer(zero));
        assertTrue(q.offer(one));
    }

    /**
     * Offer of non-Comparable throws CCE
     */
    public void testOfferNonComparable() {
        PriorityQueue q = new PriorityQueue(1);
        try {
            q.offer(new Object());
            shouldThrow();
        } catch (ClassCastException success) {
            assertTrue(q.isEmpty());
            assertEquals(0, q.size());
            assertNull(q.poll());
        }
    }

    /**
     * add of comparable succeeds
     */
    public void testAdd() {
        PriorityQueue q = new PriorityQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.size());
            assertTrue(q.add(new Integer(i)));
        }
    }

    /**
     * addAll(null) throws NPE
     */
    public void testAddAll1() {
        PriorityQueue q = new PriorityQueue(1);
        try {
            q.addAll(null);
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * addAll of a collection with null elements throws NPE
     */
    public void testAddAll2() {
        PriorityQueue q = new PriorityQueue(SIZE);
        try {
            q.addAll(Arrays.asList(new Integer[SIZE]));
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * addAll of a collection with any null elements throws NPE after
     * possibly adding some elements
     */
    public void testAddAll3() {
        PriorityQueue q = new PriorityQueue(SIZE);
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE - 1; ++i)
            ints[i] = new Integer(i);
        try {
            q.addAll(Arrays.asList(ints));
            shouldThrow();
        } catch (NullPointerException success) {}
    }

    /**
     * Queue contains all elements of successful addAll
     */
    public void testAddAll5() {
        Integer[] empty = new Integer[0];
        Integer[] ints = new Integer[SIZE];
        for (int i = 0; i < SIZE; ++i)
            ints[i] = new Integer(SIZE - 1 - i);
        PriorityQueue q = new PriorityQueue(SIZE);
        assertFalse(q.addAll(Arrays.asList(empty)));
        assertTrue(q.addAll(Arrays.asList(ints)));
        for (int i = 0; i < SIZE; ++i)
            assertEquals(new Integer(i), q.poll());
    }

    /**
     * poll succeeds unless empty
     */
    public void testPoll() {
        PriorityQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.poll());
        }
        assertNull(q.poll());
    }

    /**
     * peek returns next element, or null if empty
     */
    public void testPeek() {
        PriorityQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.peek());
            assertEquals(i, q.poll());
            assertTrue(q.peek() == null ||
                       !q.peek().equals(i));
        }
        assertNull(q.peek());
    }

    /**
     * element returns next element, or throws NSEE if empty
     */
    public void testElement() {
        PriorityQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.element());
            assertEquals(i, q.poll());
        }
        try {
            q.element();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * remove removes next element, or throws NSEE if empty
     */
    public void testRemove() {
        PriorityQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertEquals(i, q.remove());
        }
        try {
            q.remove();
            shouldThrow();
        } catch (NoSuchElementException success) {}
    }

    /**
     * remove(x) removes x and returns true if present
     */
    public void testRemoveElement() {
        PriorityQueue q = populatedQueue(SIZE);
        for (int i = 1; i < SIZE; i += 2) {
            assertTrue(q.contains(i));
            assertTrue(q.remove(i));
            assertFalse(q.contains(i));
            assertTrue(q.contains(i - 1));
        }
        for (int i = 0; i < SIZE; i += 2) {
            assertTrue(q.contains(i));
            assertTrue(q.remove(i));
            assertFalse(q.contains(i));
            assertFalse(q.remove(i + 1));
            assertFalse(q.contains(i + 1));
        }
        assertTrue(q.isEmpty());
    }

    /**
     * contains(x) reports true when elements added but not yet removed
     */
    public void testContains() {
        PriorityQueue q = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(q.contains(new Integer(i)));
            q.poll();
            assertFalse(q.contains(new Integer(i)));
        }
    }

    /**
     * clear removes all elements
     */
    public void testClear() {
        PriorityQueue q = populatedQueue(SIZE);
        q.clear();
        assertTrue(q.isEmpty());
        assertEquals(0, q.size());
        q.add(new Integer(1));
        assertFalse(q.isEmpty());
        q.clear();
        assertTrue(q.isEmpty());
    }

    /**
     * containsAll(c) is true when c contains a subset of elements
     */
    public void testContainsAll() {
        PriorityQueue q = populatedQueue(SIZE);
        PriorityQueue p = new PriorityQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(q.containsAll(p));
            assertFalse(p.containsAll(q));
            p.add(new Integer(i));
        }
        assertTrue(p.containsAll(q));
    }

    /**
     * retainAll(c) retains only those elements of c and reports true if changed
     */
    public void testRetainAll() {
        PriorityQueue q = populatedQueue(SIZE);
        PriorityQueue p = populatedQueue(SIZE);
        for (int i = 0; i < SIZE; ++i) {
            boolean changed = q.retainAll(p);
            if (i == 0)
                assertFalse(changed);
            else
                assertTrue(changed);

            assertTrue(q.containsAll(p));
            assertEquals(SIZE - i, q.size());
            p.remove();
        }
    }

    /**
     * removeAll(c) removes only those elements of c and reports true if changed
     */
    public void testRemoveAll() {
        for (int i = 1; i < SIZE; ++i) {
            PriorityQueue q = populatedQueue(SIZE);
            PriorityQueue p = populatedQueue(i);
            assertTrue(q.removeAll(p));
            assertEquals(SIZE - i, q.size());
            for (int j = 0; j < i; ++j) {
                Integer x = (Integer)(p.remove());
                assertFalse(q.contains(x));
            }
        }
    }

    /**
     * toArray contains all elements
     */
    public void testToArray() {
        PriorityQueue q = populatedQueue(SIZE);
        Object[] o = q.toArray();
        Arrays.sort(o);
        for (int i = 0; i < o.length; i++)
            assertSame(o[i], q.poll());
    }

    /**
     * toArray(a) contains all elements
     */
    public void testToArray2() {
        PriorityQueue<Integer> q = populatedQueue(SIZE);
        Integer[] ints = new Integer[SIZE];
        Integer[] array = q.toArray(ints);
        assertSame(ints, array);
        Arrays.sort(ints);
        for (int i = 0; i < ints.length; i++)
            assertSame(ints[i], q.poll());
    }

    /**
     * iterator iterates through all elements
     */
    public void testIterator() {
        PriorityQueue q = populatedQueue(SIZE);
        Iterator it = q.iterator();
        int i;
        for (i = 0; it.hasNext(); i++)
            assertTrue(q.contains(it.next()));
        assertEquals(i, SIZE);
        assertIteratorExhausted(it);
    }

    /**
     * iterator of empty collection has no elements
     */
    public void testEmptyIterator() {
        assertIteratorExhausted(new PriorityQueue().iterator());
    }

    /**
     * iterator.remove removes current element
     */
    public void testIteratorRemove() {
        final PriorityQueue q = new PriorityQueue(3);
        q.add(new Integer(2));
        q.add(new Integer(1));
        q.add(new Integer(3));

        Iterator it = q.iterator();
        it.next();
        it.remove();

        it = q.iterator();
        assertEquals(it.next(), new Integer(2));
        assertEquals(it.next(), new Integer(3));
        assertFalse(it.hasNext());
    }

    /**
     * toString contains toStrings of elements
     */
    public void testToString() {
        PriorityQueue q = populatedQueue(SIZE);
        String s = q.toString();
        for (int i = 0; i < SIZE; ++i) {
            assertTrue(s.contains(String.valueOf(i)));
        }
    }

    /**
     * A deserialized serialized queue has same elements
     */
    public void testSerialization() throws Exception {
        Queue x = populatedQueue(SIZE);
        Queue y = serialClone(x);

        assertNotSame(x, y);
        assertEquals(x.size(), y.size());
        while (!x.isEmpty()) {
            assertFalse(y.isEmpty());
            assertEquals(x.remove(), y.remove());
        }
        assertTrue(y.isEmpty());
    }
}
Revision:	1.37
Committed:	Wed Jun 1 16:08:04 2016 UTC (7 years, 11 months ago) by jsr166
Branch:	MAIN
Changes since 1.36:	+5 -2 lines
Log Message:	8066070: PriorityQueue corrupted when adding non-Comparable
#	Content
1	/*
2	* Written by Doug Lea with assistance from members of JCP JSR-166
3	* Expert Group and released to the public domain, as explained at
4	* http://creativecommons.org/publicdomain/zero/1.0/
5	* Other contributors include Andrew Wright, Jeffrey Hayes,
6	* Pat Fisher, Mike Judd.
7	*/
8
9	import java.util.Arrays;
10	import java.util.Collection;
11	import java.util.Comparator;
12	import java.util.Iterator;
13	import java.util.NoSuchElementException;
14	import java.util.PriorityQueue;
15	import java.util.Queue;
16
17	import junit.framework.Test;
18	import junit.framework.TestSuite;
19
20	public class PriorityQueueTest extends JSR166TestCase {
21	public static void main(String[] args) {
22	main(suite(), args);
23	}
24	public static Test suite() {
25	return new TestSuite(PriorityQueueTest.class);
26	}
27
28	static class MyReverseComparator implements Comparator {
29	public int compare(Object x, Object y) {
30	return ((Comparable)y).compareTo(x);
31	}
32	}
33
34	/**
35	* Returns a new queue of given size containing consecutive
36	* Integers 0 ... n.
37	*/
38	private PriorityQueue<Integer> populatedQueue(int n) {
39	PriorityQueue<Integer> q = new PriorityQueue<Integer>(n);
40	assertTrue(q.isEmpty());
41	for (int i = n - 1; i >= 0; i -= 2)
42	assertTrue(q.offer(new Integer(i)));
43	for (int i = (n & 1); i < n; i += 2)
44	assertTrue(q.offer(new Integer(i)));
45	assertFalse(q.isEmpty());
46	assertEquals(n, q.size());
47	return q;
48	}
49
50	/**
51	* A new queue has unbounded capacity
52	*/
53	public void testConstructor1() {
54	assertEquals(0, new PriorityQueue(SIZE).size());
55	}
56
57	/**
58	* Constructor throws IAE if capacity argument nonpositive
59	*/
60	public void testConstructor2() {
61	try {
62	new PriorityQueue(0);
63	shouldThrow();
64	} catch (IllegalArgumentException success) {}
65	}
66
67	/**
68	* Initializing from null Collection throws NPE
69	*/
70	public void testConstructor3() {
71	try {
72	new PriorityQueue((Collection)null);
73	shouldThrow();
74	} catch (NullPointerException success) {}
75	}
76
77	/**
78	* Initializing from Collection of null elements throws NPE
79	*/
80	public void testConstructor4() {
81	try {
82	new PriorityQueue(Arrays.asList(new Integer[SIZE]));
83	shouldThrow();
84	} catch (NullPointerException success) {}
85	}
86
87	/**
88	* Initializing from Collection with some null elements throws NPE
89	*/
90	public void testConstructor5() {
91	Integer[] ints = new Integer[SIZE];
92	for (int i = 0; i < SIZE - 1; ++i)
93	ints[i] = new Integer(i);
94	try {
95	new PriorityQueue(Arrays.asList(ints));
96	shouldThrow();
97	} catch (NullPointerException success) {}
98	}
99
100	/**
101	* Queue contains all elements of collection used to initialize
102	*/
103	public void testConstructor6() {
104	Integer[] ints = new Integer[SIZE];
105	for (int i = 0; i < SIZE; ++i)
106	ints[i] = new Integer(i);
107	PriorityQueue q = new PriorityQueue(Arrays.asList(ints));
108	for (int i = 0; i < SIZE; ++i)
109	assertEquals(ints[i], q.poll());
110	}
111
112	/**
113	* The comparator used in constructor is used
114	*/
115	public void testConstructor7() {
116	MyReverseComparator cmp = new MyReverseComparator();
117	PriorityQueue q = new PriorityQueue(SIZE, cmp);
118	assertEquals(cmp, q.comparator());
119	Integer[] ints = new Integer[SIZE];
120	for (int i = 0; i < SIZE; ++i)
121	ints[i] = new Integer(i);
122	q.addAll(Arrays.asList(ints));
123	for (int i = SIZE - 1; i >= 0; --i)
124	assertEquals(ints[i], q.poll());
125	}
126
127	/**
128	* isEmpty is true before add, false after
129	*/
130	public void testEmpty() {
131	PriorityQueue q = new PriorityQueue(2);
132	assertTrue(q.isEmpty());
133	q.add(new Integer(1));
134	assertFalse(q.isEmpty());
135	q.add(new Integer(2));
136	q.remove();
137	q.remove();
138	assertTrue(q.isEmpty());
139	}
140
141	/**
142	* size changes when elements added and removed
143	*/
144	public void testSize() {
145	PriorityQueue q = populatedQueue(SIZE);
146	for (int i = 0; i < SIZE; ++i) {
147	assertEquals(SIZE - i, q.size());
148	q.remove();
149	}
150	for (int i = 0; i < SIZE; ++i) {
151	assertEquals(i, q.size());
152	q.add(new Integer(i));
153	}
154	}
155
156	/**
157	* offer(null) throws NPE
158	*/
159	public void testOfferNull() {
160	PriorityQueue q = new PriorityQueue(1);
161	try {
162	q.offer(null);
163	shouldThrow();
164	} catch (NullPointerException success) {}
165	}
166
167	/**
168	* add(null) throws NPE
169	*/
170	public void testAddNull() {
171	PriorityQueue q = new PriorityQueue(1);
172	try {
173	q.add(null);
174	shouldThrow();
175	} catch (NullPointerException success) {}
176	}
177
178	/**
179	* Offer of comparable element succeeds
180	*/
181	public void testOffer() {
182	PriorityQueue q = new PriorityQueue(1);
183	assertTrue(q.offer(zero));
184	assertTrue(q.offer(one));
185	}
186
187	/**
188	* Offer of non-Comparable throws CCE
189	*/
190	public void testOfferNonComparable() {
191	PriorityQueue q = new PriorityQueue(1);
192	try {
193	q.offer(new Object());
194	shouldThrow();
195	} catch (ClassCastException success) {
196	assertTrue(q.isEmpty());
197	assertEquals(0, q.size());
198	assertNull(q.poll());
199	}
200	}
201
202	/**
203	* add of comparable succeeds
204	*/
205	public void testAdd() {
206	PriorityQueue q = new PriorityQueue(SIZE);
207	for (int i = 0; i < SIZE; ++i) {
208	assertEquals(i, q.size());
209	assertTrue(q.add(new Integer(i)));
210	}
211	}
212
213	/**
214	* addAll(null) throws NPE
215	*/
216	public void testAddAll1() {
217	PriorityQueue q = new PriorityQueue(1);
218	try {
219	q.addAll(null);
220	shouldThrow();
221	} catch (NullPointerException success) {}
222	}
223
224	/**
225	* addAll of a collection with null elements throws NPE
226	*/
227	public void testAddAll2() {
228	PriorityQueue q = new PriorityQueue(SIZE);
229	try {
230	q.addAll(Arrays.asList(new Integer[SIZE]));
231	shouldThrow();
232	} catch (NullPointerException success) {}
233	}
234
235	/**
236	* addAll of a collection with any null elements throws NPE after
237	* possibly adding some elements
238	*/
239	public void testAddAll3() {
240	PriorityQueue q = new PriorityQueue(SIZE);
241	Integer[] ints = new Integer[SIZE];
242	for (int i = 0; i < SIZE - 1; ++i)
243	ints[i] = new Integer(i);
244	try {
245	q.addAll(Arrays.asList(ints));
246	shouldThrow();
247	} catch (NullPointerException success) {}
248	}
249
250	/**
251	* Queue contains all elements of successful addAll
252	*/
253	public void testAddAll5() {
254	Integer[] empty = new Integer[0];
255	Integer[] ints = new Integer[SIZE];
256	for (int i = 0; i < SIZE; ++i)
257	ints[i] = new Integer(SIZE - 1 - i);
258	PriorityQueue q = new PriorityQueue(SIZE);
259	assertFalse(q.addAll(Arrays.asList(empty)));
260	assertTrue(q.addAll(Arrays.asList(ints)));
261	for (int i = 0; i < SIZE; ++i)
262	assertEquals(new Integer(i), q.poll());
263	}
264
265	/**
266	* poll succeeds unless empty
267	*/
268	public void testPoll() {
269	PriorityQueue q = populatedQueue(SIZE);
270	for (int i = 0; i < SIZE; ++i) {
271	assertEquals(i, q.poll());
272	}
273	assertNull(q.poll());
274	}
275
276	/**
277	* peek returns next element, or null if empty
278	*/
279	public void testPeek() {
280	PriorityQueue q = populatedQueue(SIZE);
281	for (int i = 0; i < SIZE; ++i) {
282	assertEquals(i, q.peek());
283	assertEquals(i, q.poll());
284	assertTrue(q.peek() == null \|\|
285	!q.peek().equals(i));
286	}
287	assertNull(q.peek());
288	}
289
290	/**
291	* element returns next element, or throws NSEE if empty
292	*/
293	public void testElement() {
294	PriorityQueue q = populatedQueue(SIZE);
295	for (int i = 0; i < SIZE; ++i) {
296	assertEquals(i, q.element());
297	assertEquals(i, q.poll());
298	}
299	try {
300	q.element();
301	shouldThrow();
302	} catch (NoSuchElementException success) {}
303	}
304
305	/**
306	* remove removes next element, or throws NSEE if empty
307	*/
308	public void testRemove() {
309	PriorityQueue q = populatedQueue(SIZE);
310	for (int i = 0; i < SIZE; ++i) {
311	assertEquals(i, q.remove());
312	}
313	try {
314	q.remove();
315	shouldThrow();
316	} catch (NoSuchElementException success) {}
317	}
318
319	/**
320	* remove(x) removes x and returns true if present
321	*/
322	public void testRemoveElement() {
323	PriorityQueue q = populatedQueue(SIZE);
324	for (int i = 1; i < SIZE; i += 2) {
325	assertTrue(q.contains(i));
326	assertTrue(q.remove(i));
327	assertFalse(q.contains(i));
328	assertTrue(q.contains(i - 1));
329	}
330	for (int i = 0; i < SIZE; i += 2) {
331	assertTrue(q.contains(i));
332	assertTrue(q.remove(i));
333	assertFalse(q.contains(i));
334	assertFalse(q.remove(i + 1));
335	assertFalse(q.contains(i + 1));
336	}
337	assertTrue(q.isEmpty());
338	}
339
340	/**
341	* contains(x) reports true when elements added but not yet removed
342	*/
343	public void testContains() {
344	PriorityQueue q = populatedQueue(SIZE);
345	for (int i = 0; i < SIZE; ++i) {
346	assertTrue(q.contains(new Integer(i)));
347	q.poll();
348	assertFalse(q.contains(new Integer(i)));
349	}
350	}
351
352	/**
353	* clear removes all elements
354	*/
355	public void testClear() {
356	PriorityQueue q = populatedQueue(SIZE);
357	q.clear();
358	assertTrue(q.isEmpty());
359	assertEquals(0, q.size());
360	q.add(new Integer(1));
361	assertFalse(q.isEmpty());
362	q.clear();
363	assertTrue(q.isEmpty());
364	}
365
366	/**
367	* containsAll(c) is true when c contains a subset of elements
368	*/
369	public void testContainsAll() {
370	PriorityQueue q = populatedQueue(SIZE);
371	PriorityQueue p = new PriorityQueue(SIZE);
372	for (int i = 0; i < SIZE; ++i) {
373	assertTrue(q.containsAll(p));
374	assertFalse(p.containsAll(q));
375	p.add(new Integer(i));
376	}
377	assertTrue(p.containsAll(q));
378	}
379
380	/**
381	* retainAll(c) retains only those elements of c and reports true if changed
382	*/
383	public void testRetainAll() {
384	PriorityQueue q = populatedQueue(SIZE);
385	PriorityQueue p = populatedQueue(SIZE);
386	for (int i = 0; i < SIZE; ++i) {
387	boolean changed = q.retainAll(p);
388	if (i == 0)
389	assertFalse(changed);
390	else
391	assertTrue(changed);
392
393	assertTrue(q.containsAll(p));
394	assertEquals(SIZE - i, q.size());
395	p.remove();
396	}
397	}
398
399	/**
400	* removeAll(c) removes only those elements of c and reports true if changed
401	*/
402	public void testRemoveAll() {
403	for (int i = 1; i < SIZE; ++i) {
404	PriorityQueue q = populatedQueue(SIZE);
405	PriorityQueue p = populatedQueue(i);
406	assertTrue(q.removeAll(p));
407	assertEquals(SIZE - i, q.size());
408	for (int j = 0; j < i; ++j) {
409	Integer x = (Integer)(p.remove());
410	assertFalse(q.contains(x));
411	}
412	}
413	}
414
415	/**
416	* toArray contains all elements
417	*/
418	public void testToArray() {
419	PriorityQueue q = populatedQueue(SIZE);
420	Object[] o = q.toArray();
421	Arrays.sort(o);
422	for (int i = 0; i < o.length; i++)
423	assertSame(o[i], q.poll());
424	}
425
426	/**
427	* toArray(a) contains all elements
428	*/
429	public void testToArray2() {
430	PriorityQueue<Integer> q = populatedQueue(SIZE);
431	Integer[] ints = new Integer[SIZE];
432	Integer[] array = q.toArray(ints);
433	assertSame(ints, array);
434	Arrays.sort(ints);
435	for (int i = 0; i < ints.length; i++)
436	assertSame(ints[i], q.poll());
437	}
438
439	/**
440	* iterator iterates through all elements
441	*/
442	public void testIterator() {
443	PriorityQueue q = populatedQueue(SIZE);
444	Iterator it = q.iterator();
445	int i;
446	for (i = 0; it.hasNext(); i++)
447	assertTrue(q.contains(it.next()));
448	assertEquals(i, SIZE);
449	assertIteratorExhausted(it);
450	}
451
452	/**
453	* iterator of empty collection has no elements
454	*/
455	public void testEmptyIterator() {
456	assertIteratorExhausted(new PriorityQueue().iterator());
457	}
458
459	/**
460	* iterator.remove removes current element
461	*/
462	public void testIteratorRemove() {
463	final PriorityQueue q = new PriorityQueue(3);
464	q.add(new Integer(2));
465	q.add(new Integer(1));
466	q.add(new Integer(3));
467
468	Iterator it = q.iterator();
469	it.next();
470	it.remove();
471
472	it = q.iterator();
473	assertEquals(it.next(), new Integer(2));
474	assertEquals(it.next(), new Integer(3));
475	assertFalse(it.hasNext());
476	}
477
478	/**
479	* toString contains toStrings of elements
480	*/
481	public void testToString() {
482	PriorityQueue q = populatedQueue(SIZE);
483	String s = q.toString();
484	for (int i = 0; i < SIZE; ++i) {
485	assertTrue(s.contains(String.valueOf(i)));
486	}
487	}
488
489	/**
490	* A deserialized serialized queue has same elements
491	*/
492	public void testSerialization() throws Exception {
493	Queue x = populatedQueue(SIZE);
494	Queue y = serialClone(x);
495
496	assertNotSame(x, y);
497	assertEquals(x.size(), y.size());
498	while (!x.isEmpty()) {
499	assertFalse(y.isEmpty());
500	assertEquals(x.remove(), y.remove());
501	}
502	assertTrue(y.isEmpty());
503	}
504	}