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 junit.framework.*;
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;

public class PriorityQueueTest extends JSR166TestCase {
    public static void main(String[] args) {
        junit.textui.TestRunner.run(suite());
    }
    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 {
            PriorityQueue q = new PriorityQueue(0);
            shouldThrow();
        } catch (IllegalArgumentException success) {}
    }

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

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

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

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

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

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

    /**
     * addAll of a collection with any null elements throws NPE after
     * possibly adding some elements
     */
    public void testAddAll3() {
        try {
            PriorityQueue q = new PriorityQueue(SIZE);
            Integer[] ints = new Integer[SIZE];
            for (int i = 0; i < SIZE-1; ++i)
                ints[i] = new Integer(i);
            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 I = (Integer)(p.remove());
                assertFalse(q.contains(I));
            }
        }
    }

    /**
     * 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);
        int i = 0;
        Iterator it = q.iterator();
        while (it.hasNext()) {
            assertTrue(q.contains(it.next()));
            ++i;
        }
        assertEquals(i, SIZE);
    }

    /**
     * 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);

        assertTrue(x != y);
        assertEquals(x.size(), y.size());
        while (!x.isEmpty()) {
            assertFalse(y.isEmpty());
            assertEquals(x.remove(), y.remove());
        }
        assertTrue(y.isEmpty());
    }
}
Revision:	1.25
Committed:	Tue Feb 21 02:04:17 2012 UTC (12 years, 2 months ago) by jsr166
Branch:	MAIN
Changes since 1.24:	+1 -1 lines
Log Message:	slightly clearer javadoc
#	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 junit.framework.*;
10	import java.util.Arrays;
11	import java.util.Collection;
12	import java.util.Comparator;
13	import java.util.Iterator;
14	import java.util.NoSuchElementException;
15	import java.util.PriorityQueue;
16	import java.util.Queue;
17
18	public class PriorityQueueTest extends JSR166TestCase {
19	public static void main(String[] args) {
20	junit.textui.TestRunner.run(suite());
21	}
22	public static Test suite() {
23	return new TestSuite(PriorityQueueTest.class);
24	}
25
26	static class MyReverseComparator implements Comparator {
27	public int compare(Object x, Object y) {
28	return ((Comparable)y).compareTo(x);
29	}
30	}
31
32	/**
33	* Returns a new queue of given size containing consecutive
34	* Integers 0 ... n.
35	*/
36	private PriorityQueue<Integer> populatedQueue(int n) {
37	PriorityQueue<Integer> q = new PriorityQueue<Integer>(n);
38	assertTrue(q.isEmpty());
39	for (int i = n-1; i >= 0; i-=2)
40	assertTrue(q.offer(new Integer(i)));
41	for (int i = (n & 1); i < n; i+=2)
42	assertTrue(q.offer(new Integer(i)));
43	assertFalse(q.isEmpty());
44	assertEquals(n, q.size());
45	return q;
46	}
47
48	/**
49	* A new queue has unbounded capacity
50	*/
51	public void testConstructor1() {
52	assertEquals(0, new PriorityQueue(SIZE).size());
53	}
54
55	/**
56	* Constructor throws IAE if capacity argument nonpositive
57	*/
58	public void testConstructor2() {
59	try {
60	PriorityQueue q = new PriorityQueue(0);
61	shouldThrow();
62	} catch (IllegalArgumentException success) {}
63	}
64
65	/**
66	* Initializing from null Collection throws NPE
67	*/
68	public void testConstructor3() {
69	try {
70	PriorityQueue q = new PriorityQueue((Collection)null);
71	shouldThrow();
72	} catch (NullPointerException success) {}
73	}
74
75	/**
76	* Initializing from Collection of null elements throws NPE
77	*/
78	public void testConstructor4() {
79	try {
80	Integer[] ints = new Integer[SIZE];
81	PriorityQueue q = new PriorityQueue(Arrays.asList(ints));
82	shouldThrow();
83	} catch (NullPointerException success) {}
84	}
85
86	/**
87	* Initializing from Collection with some null elements throws NPE
88	*/
89	public void testConstructor5() {
90	try {
91	Integer[] ints = new Integer[SIZE];
92	for (int i = 0; i < SIZE-1; ++i)
93	ints[i] = new Integer(i);
94	PriorityQueue q = new PriorityQueue(Arrays.asList(ints));
95	shouldThrow();
96	} catch (NullPointerException success) {}
97	}
98
99	/**
100	* Queue contains all elements of collection used to initialize
101	*/
102	public void testConstructor6() {
103	Integer[] ints = new Integer[SIZE];
104	for (int i = 0; i < SIZE; ++i)
105	ints[i] = new Integer(i);
106	PriorityQueue q = new PriorityQueue(Arrays.asList(ints));
107	for (int i = 0; i < SIZE; ++i)
108	assertEquals(ints[i], q.poll());
109	}
110
111	/**
112	* The comparator used in constructor is used
113	*/
114	public void testConstructor7() {
115	MyReverseComparator cmp = new MyReverseComparator();
116	PriorityQueue q = new PriorityQueue(SIZE, cmp);
117	assertEquals(cmp, q.comparator());
118	Integer[] ints = new Integer[SIZE];
119	for (int i = 0; i < SIZE; ++i)
120	ints[i] = new Integer(i);
121	q.addAll(Arrays.asList(ints));
122	for (int i = SIZE-1; i >= 0; --i)
123	assertEquals(ints[i], q.poll());
124	}
125
126	/**
127	* isEmpty is true before add, false after
128	*/
129	public void testEmpty() {
130	PriorityQueue q = new PriorityQueue(2);
131	assertTrue(q.isEmpty());
132	q.add(new Integer(1));
133	assertFalse(q.isEmpty());
134	q.add(new Integer(2));
135	q.remove();
136	q.remove();
137	assertTrue(q.isEmpty());
138	}
139
140	/**
141	* size changes when elements added and removed
142	*/
143	public void testSize() {
144	PriorityQueue q = populatedQueue(SIZE);
145	for (int i = 0; i < SIZE; ++i) {
146	assertEquals(SIZE-i, q.size());
147	q.remove();
148	}
149	for (int i = 0; i < SIZE; ++i) {
150	assertEquals(i, q.size());
151	q.add(new Integer(i));
152	}
153	}
154
155	/**
156	* offer(null) throws NPE
157	*/
158	public void testOfferNull() {
159	try {
160	PriorityQueue q = new PriorityQueue(1);
161	q.offer(null);
162	shouldThrow();
163	} catch (NullPointerException success) {}
164	}
165
166	/**
167	* add(null) throws NPE
168	*/
169	public void testAddNull() {
170	try {
171	PriorityQueue q = new PriorityQueue(1);
172	q.add(null);
173	shouldThrow();
174	} catch (NullPointerException success) {}
175	}
176
177	/**
178	* Offer of comparable element succeeds
179	*/
180	public void testOffer() {
181	PriorityQueue q = new PriorityQueue(1);
182	assertTrue(q.offer(zero));
183	assertTrue(q.offer(one));
184	}
185
186	/**
187	* Offer of non-Comparable throws CCE
188	*/
189	public void testOfferNonComparable() {
190	try {
191	PriorityQueue q = new PriorityQueue(1);
192	q.offer(new Object());
193	q.offer(new Object());
194	q.offer(new Object());
195	shouldThrow();
196	} catch (ClassCastException success) {}
197	}
198
199	/**
200	* add of comparable succeeds
201	*/
202	public void testAdd() {
203	PriorityQueue q = new PriorityQueue(SIZE);
204	for (int i = 0; i < SIZE; ++i) {
205	assertEquals(i, q.size());
206	assertTrue(q.add(new Integer(i)));
207	}
208	}
209
210	/**
211	* addAll(null) throws NPE
212	*/
213	public void testAddAll1() {
214	try {
215	PriorityQueue q = new PriorityQueue(1);
216	q.addAll(null);
217	shouldThrow();
218	} catch (NullPointerException success) {}
219	}
220
221	/**
222	* addAll of a collection with null elements throws NPE
223	*/
224	public void testAddAll2() {
225	try {
226	PriorityQueue q = new PriorityQueue(SIZE);
227	Integer[] ints = new Integer[SIZE];
228	q.addAll(Arrays.asList(ints));
229	shouldThrow();
230	} catch (NullPointerException success) {}
231	}
232
233	/**
234	* addAll of a collection with any null elements throws NPE after
235	* possibly adding some elements
236	*/
237	public void testAddAll3() {
238	try {
239	PriorityQueue q = new PriorityQueue(SIZE);
240	Integer[] ints = new Integer[SIZE];
241	for (int i = 0; i < SIZE-1; ++i)
242	ints[i] = new Integer(i);
243	q.addAll(Arrays.asList(ints));
244	shouldThrow();
245	} catch (NullPointerException success) {}
246	}
247
248	/**
249	* Queue contains all elements of successful addAll
250	*/
251	public void testAddAll5() {
252	Integer[] empty = new Integer[0];
253	Integer[] ints = new Integer[SIZE];
254	for (int i = 0; i < SIZE; ++i)
255	ints[i] = new Integer(SIZE-1-i);
256	PriorityQueue q = new PriorityQueue(SIZE);
257	assertFalse(q.addAll(Arrays.asList(empty)));
258	assertTrue(q.addAll(Arrays.asList(ints)));
259	for (int i = 0; i < SIZE; ++i)
260	assertEquals(new Integer(i), q.poll());
261	}
262
263	/**
264	* poll succeeds unless empty
265	*/
266	public void testPoll() {
267	PriorityQueue q = populatedQueue(SIZE);
268	for (int i = 0; i < SIZE; ++i) {
269	assertEquals(i, q.poll());
270	}
271	assertNull(q.poll());
272	}
273
274	/**
275	* peek returns next element, or null if empty
276	*/
277	public void testPeek() {
278	PriorityQueue q = populatedQueue(SIZE);
279	for (int i = 0; i < SIZE; ++i) {
280	assertEquals(i, q.peek());
281	assertEquals(i, q.poll());
282	assertTrue(q.peek() == null \|\|
283	!q.peek().equals(i));
284	}
285	assertNull(q.peek());
286	}
287
288	/**
289	* element returns next element, or throws NSEE if empty
290	*/
291	public void testElement() {
292	PriorityQueue q = populatedQueue(SIZE);
293	for (int i = 0; i < SIZE; ++i) {
294	assertEquals(i, q.element());
295	assertEquals(i, q.poll());
296	}
297	try {
298	q.element();
299	shouldThrow();
300	} catch (NoSuchElementException success) {}
301	}
302
303	/**
304	* remove removes next element, or throws NSEE if empty
305	*/
306	public void testRemove() {
307	PriorityQueue q = populatedQueue(SIZE);
308	for (int i = 0; i < SIZE; ++i) {
309	assertEquals(i, q.remove());
310	}
311	try {
312	q.remove();
313	shouldThrow();
314	} catch (NoSuchElementException success) {}
315	}
316
317	/**
318	* remove(x) removes x and returns true if present
319	*/
320	public void testRemoveElement() {
321	PriorityQueue q = populatedQueue(SIZE);
322	for (int i = 1; i < SIZE; i+=2) {
323	assertTrue(q.contains(i));
324	assertTrue(q.remove(i));
325	assertFalse(q.contains(i));
326	assertTrue(q.contains(i-1));
327	}
328	for (int i = 0; i < SIZE; i+=2) {
329	assertTrue(q.contains(i));
330	assertTrue(q.remove(i));
331	assertFalse(q.contains(i));
332	assertFalse(q.remove(i+1));
333	assertFalse(q.contains(i+1));
334	}
335	assertTrue(q.isEmpty());
336	}
337
338	/**
339	* contains(x) reports true when elements added but not yet removed
340	*/
341	public void testContains() {
342	PriorityQueue q = populatedQueue(SIZE);
343	for (int i = 0; i < SIZE; ++i) {
344	assertTrue(q.contains(new Integer(i)));
345	q.poll();
346	assertFalse(q.contains(new Integer(i)));
347	}
348	}
349
350	/**
351	* clear removes all elements
352	*/
353	public void testClear() {
354	PriorityQueue q = populatedQueue(SIZE);
355	q.clear();
356	assertTrue(q.isEmpty());
357	assertEquals(0, q.size());
358	q.add(new Integer(1));
359	assertFalse(q.isEmpty());
360	q.clear();
361	assertTrue(q.isEmpty());
362	}
363
364	/**
365	* containsAll(c) is true when c contains a subset of elements
366	*/
367	public void testContainsAll() {
368	PriorityQueue q = populatedQueue(SIZE);
369	PriorityQueue p = new PriorityQueue(SIZE);
370	for (int i = 0; i < SIZE; ++i) {
371	assertTrue(q.containsAll(p));
372	assertFalse(p.containsAll(q));
373	p.add(new Integer(i));
374	}
375	assertTrue(p.containsAll(q));
376	}
377
378	/**
379	* retainAll(c) retains only those elements of c and reports true if changed
380	*/
381	public void testRetainAll() {
382	PriorityQueue q = populatedQueue(SIZE);
383	PriorityQueue p = populatedQueue(SIZE);
384	for (int i = 0; i < SIZE; ++i) {
385	boolean changed = q.retainAll(p);
386	if (i == 0)
387	assertFalse(changed);
388	else
389	assertTrue(changed);
390
391	assertTrue(q.containsAll(p));
392	assertEquals(SIZE-i, q.size());
393	p.remove();
394	}
395	}
396
397	/**
398	* removeAll(c) removes only those elements of c and reports true if changed
399	*/
400	public void testRemoveAll() {
401	for (int i = 1; i < SIZE; ++i) {
402	PriorityQueue q = populatedQueue(SIZE);
403	PriorityQueue p = populatedQueue(i);
404	assertTrue(q.removeAll(p));
405	assertEquals(SIZE-i, q.size());
406	for (int j = 0; j < i; ++j) {
407	Integer I = (Integer)(p.remove());
408	assertFalse(q.contains(I));
409	}
410	}
411	}
412
413	/**
414	* toArray contains all elements
415	*/
416	public void testToArray() {
417	PriorityQueue q = populatedQueue(SIZE);
418	Object[] o = q.toArray();
419	Arrays.sort(o);
420	for (int i = 0; i < o.length; i++)
421	assertSame(o[i], q.poll());
422	}
423
424	/**
425	* toArray(a) contains all elements
426	*/
427	public void testToArray2() {
428	PriorityQueue<Integer> q = populatedQueue(SIZE);
429	Integer[] ints = new Integer[SIZE];
430	Integer[] array = q.toArray(ints);
431	assertSame(ints, array);
432	Arrays.sort(ints);
433	for (int i = 0; i < ints.length; i++)
434	assertSame(ints[i], q.poll());
435	}
436
437	/**
438	* iterator iterates through all elements
439	*/
440	public void testIterator() {
441	PriorityQueue q = populatedQueue(SIZE);
442	int i = 0;
443	Iterator it = q.iterator();
444	while (it.hasNext()) {
445	assertTrue(q.contains(it.next()));
446	++i;
447	}
448	assertEquals(i, SIZE);
449	}
450
451	/**
452	* iterator.remove removes current element
453	*/
454	public void testIteratorRemove() {
455	final PriorityQueue q = new PriorityQueue(3);
456	q.add(new Integer(2));
457	q.add(new Integer(1));
458	q.add(new Integer(3));
459
460	Iterator it = q.iterator();
461	it.next();
462	it.remove();
463
464	it = q.iterator();
465	assertEquals(it.next(), new Integer(2));
466	assertEquals(it.next(), new Integer(3));
467	assertFalse(it.hasNext());
468	}
469
470	/**
471	* toString contains toStrings of elements
472	*/
473	public void testToString() {
474	PriorityQueue q = populatedQueue(SIZE);
475	String s = q.toString();
476	for (int i = 0; i < SIZE; ++i) {
477	assertTrue(s.contains(String.valueOf(i)));
478	}
479	}
480
481	/**
482	* A deserialized serialized queue has same elements
483	*/
484	public void testSerialization() throws Exception {
485	Queue x = populatedQueue(SIZE);
486	Queue y = serialClone(x);
487
488	assertTrue(x != y);
489	assertEquals(x.size(), y.size());
490	while (!x.isEmpty()) {
491	assertFalse(y.isEmpty());
492	assertEquals(x.remove(), y.remove());
493	}
494	assertTrue(y.isEmpty());
495	}
496	}