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 - 1.
     */
    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());
        assertEquals((Integer) 0, q.peek());
        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:	1.38
Committed:	Sun Oct 16 20:44:18 2016 UTC (7 years, 6 months ago) by jsr166
Branch:	MAIN
Changes since 1.37:	+2 -1 lines
Log Message:	improve populatedFoo methods
#	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 - 1.
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	assertEquals((Integer) 0, q.peek());
48	return q;
49	}
50
51	/**
52	* A new queue has unbounded capacity
53	*/
54	public void testConstructor1() {
55	assertEquals(0, new PriorityQueue(SIZE).size());
56	}
57
58	/**
59	* Constructor throws IAE if capacity argument nonpositive
60	*/
61	public void testConstructor2() {
62	try {
63	new PriorityQueue(0);
64	shouldThrow();
65	} catch (IllegalArgumentException success) {}
66	}
67
68	/**
69	* Initializing from null Collection throws NPE
70	*/
71	public void testConstructor3() {
72	try {
73	new PriorityQueue((Collection)null);
74	shouldThrow();
75	} catch (NullPointerException success) {}
76	}
77
78	/**
79	* Initializing from Collection of null elements throws NPE
80	*/
81	public void testConstructor4() {
82	try {
83	new PriorityQueue(Arrays.asList(new Integer[SIZE]));
84	shouldThrow();
85	} catch (NullPointerException success) {}
86	}
87
88	/**
89	* Initializing from Collection with some null elements throws NPE
90	*/
91	public void testConstructor5() {
92	Integer[] ints = new Integer[SIZE];
93	for (int i = 0; i < SIZE - 1; ++i)
94	ints[i] = new Integer(i);
95	try {
96	new PriorityQueue(Arrays.asList(ints));
97	shouldThrow();
98	} catch (NullPointerException success) {}
99	}
100
101	/**
102	* Queue contains all elements of collection used to initialize
103	*/
104	public void testConstructor6() {
105	Integer[] ints = new Integer[SIZE];
106	for (int i = 0; i < SIZE; ++i)
107	ints[i] = new Integer(i);
108	PriorityQueue q = new PriorityQueue(Arrays.asList(ints));
109	for (int i = 0; i < SIZE; ++i)
110	assertEquals(ints[i], q.poll());
111	}
112
113	/**
114	* The comparator used in constructor is used
115	*/
116	public void testConstructor7() {
117	MyReverseComparator cmp = new MyReverseComparator();
118	PriorityQueue q = new PriorityQueue(SIZE, cmp);
119	assertEquals(cmp, q.comparator());
120	Integer[] ints = new Integer[SIZE];
121	for (int i = 0; i < SIZE; ++i)
122	ints[i] = new Integer(i);
123	q.addAll(Arrays.asList(ints));
124	for (int i = SIZE - 1; i >= 0; --i)
125	assertEquals(ints[i], q.poll());
126	}
127
128	/**
129	* isEmpty is true before add, false after
130	*/
131	public void testEmpty() {
132	PriorityQueue q = new PriorityQueue(2);
133	assertTrue(q.isEmpty());
134	q.add(new Integer(1));
135	assertFalse(q.isEmpty());
136	q.add(new Integer(2));
137	q.remove();
138	q.remove();
139	assertTrue(q.isEmpty());
140	}
141
142	/**
143	* size changes when elements added and removed
144	*/
145	public void testSize() {
146	PriorityQueue q = populatedQueue(SIZE);
147	for (int i = 0; i < SIZE; ++i) {
148	assertEquals(SIZE - i, q.size());
149	q.remove();
150	}
151	for (int i = 0; i < SIZE; ++i) {
152	assertEquals(i, q.size());
153	q.add(new Integer(i));
154	}
155	}
156
157	/**
158	* offer(null) throws NPE
159	*/
160	public void testOfferNull() {
161	PriorityQueue q = new PriorityQueue(1);
162	try {
163	q.offer(null);
164	shouldThrow();
165	} catch (NullPointerException success) {}
166	}
167
168	/**
169	* add(null) throws NPE
170	*/
171	public void testAddNull() {
172	PriorityQueue q = new PriorityQueue(1);
173	try {
174	q.add(null);
175	shouldThrow();
176	} catch (NullPointerException success) {}
177	}
178
179	/**
180	* Offer of comparable element succeeds
181	*/
182	public void testOffer() {
183	PriorityQueue q = new PriorityQueue(1);
184	assertTrue(q.offer(zero));
185	assertTrue(q.offer(one));
186	}
187
188	/**
189	* Offer of non-Comparable throws CCE
190	*/
191	public void testOfferNonComparable() {
192	PriorityQueue q = new PriorityQueue(1);
193	try {
194	q.offer(new Object());
195	shouldThrow();
196	} catch (ClassCastException success) {
197	assertTrue(q.isEmpty());
198	assertEquals(0, q.size());
199	assertNull(q.poll());
200	}
201	}
202
203	/**
204	* add of comparable succeeds
205	*/
206	public void testAdd() {
207	PriorityQueue q = new PriorityQueue(SIZE);
208	for (int i = 0; i < SIZE; ++i) {
209	assertEquals(i, q.size());
210	assertTrue(q.add(new Integer(i)));
211	}
212	}
213
214	/**
215	* addAll(null) throws NPE
216	*/
217	public void testAddAll1() {
218	PriorityQueue q = new PriorityQueue(1);
219	try {
220	q.addAll(null);
221	shouldThrow();
222	} catch (NullPointerException success) {}
223	}
224
225	/**
226	* addAll of a collection with null elements throws NPE
227	*/
228	public void testAddAll2() {
229	PriorityQueue q = new PriorityQueue(SIZE);
230	try {
231	q.addAll(Arrays.asList(new Integer[SIZE]));
232	shouldThrow();
233	} catch (NullPointerException success) {}
234	}
235
236	/**
237	* addAll of a collection with any null elements throws NPE after
238	* possibly adding some elements
239	*/
240	public void testAddAll3() {
241	PriorityQueue q = new PriorityQueue(SIZE);
242	Integer[] ints = new Integer[SIZE];
243	for (int i = 0; i < SIZE - 1; ++i)
244	ints[i] = new Integer(i);
245	try {
246	q.addAll(Arrays.asList(ints));
247	shouldThrow();
248	} catch (NullPointerException success) {}
249	}
250
251	/**
252	* Queue contains all elements of successful addAll
253	*/
254	public void testAddAll5() {
255	Integer[] empty = new Integer[0];
256	Integer[] ints = new Integer[SIZE];
257	for (int i = 0; i < SIZE; ++i)
258	ints[i] = new Integer(SIZE - 1 - i);
259	PriorityQueue q = new PriorityQueue(SIZE);
260	assertFalse(q.addAll(Arrays.asList(empty)));
261	assertTrue(q.addAll(Arrays.asList(ints)));
262	for (int i = 0; i < SIZE; ++i)
263	assertEquals(new Integer(i), q.poll());
264	}
265
266	/**
267	* poll succeeds unless empty
268	*/
269	public void testPoll() {
270	PriorityQueue q = populatedQueue(SIZE);
271	for (int i = 0; i < SIZE; ++i) {
272	assertEquals(i, q.poll());
273	}
274	assertNull(q.poll());
275	}
276
277	/**
278	* peek returns next element, or null if empty
279	*/
280	public void testPeek() {
281	PriorityQueue q = populatedQueue(SIZE);
282	for (int i = 0; i < SIZE; ++i) {
283	assertEquals(i, q.peek());
284	assertEquals(i, q.poll());
285	assertTrue(q.peek() == null \|\|
286	!q.peek().equals(i));
287	}
288	assertNull(q.peek());
289	}
290
291	/**
292	* element returns next element, or throws NSEE if empty
293	*/
294	public void testElement() {
295	PriorityQueue q = populatedQueue(SIZE);
296	for (int i = 0; i < SIZE; ++i) {
297	assertEquals(i, q.element());
298	assertEquals(i, q.poll());
299	}
300	try {
301	q.element();
302	shouldThrow();
303	} catch (NoSuchElementException success) {}
304	}
305
306	/**
307	* remove removes next element, or throws NSEE if empty
308	*/
309	public void testRemove() {
310	PriorityQueue q = populatedQueue(SIZE);
311	for (int i = 0; i < SIZE; ++i) {
312	assertEquals(i, q.remove());
313	}
314	try {
315	q.remove();
316	shouldThrow();
317	} catch (NoSuchElementException success) {}
318	}
319
320	/**
321	* remove(x) removes x and returns true if present
322	*/
323	public void testRemoveElement() {
324	PriorityQueue q = populatedQueue(SIZE);
325	for (int i = 1; i < SIZE; i += 2) {
326	assertTrue(q.contains(i));
327	assertTrue(q.remove(i));
328	assertFalse(q.contains(i));
329	assertTrue(q.contains(i - 1));
330	}
331	for (int i = 0; i < SIZE; i += 2) {
332	assertTrue(q.contains(i));
333	assertTrue(q.remove(i));
334	assertFalse(q.contains(i));
335	assertFalse(q.remove(i + 1));
336	assertFalse(q.contains(i + 1));
337	}
338	assertTrue(q.isEmpty());
339	}
340
341	/**
342	* contains(x) reports true when elements added but not yet removed
343	*/
344	public void testContains() {
345	PriorityQueue q = populatedQueue(SIZE);
346	for (int i = 0; i < SIZE; ++i) {
347	assertTrue(q.contains(new Integer(i)));
348	q.poll();
349	assertFalse(q.contains(new Integer(i)));
350	}
351	}
352
353	/**
354	* clear removes all elements
355	*/
356	public void testClear() {
357	PriorityQueue q = populatedQueue(SIZE);
358	q.clear();
359	assertTrue(q.isEmpty());
360	assertEquals(0, q.size());
361	q.add(new Integer(1));
362	assertFalse(q.isEmpty());
363	q.clear();
364	assertTrue(q.isEmpty());
365	}
366
367	/**
368	* containsAll(c) is true when c contains a subset of elements
369	*/
370	public void testContainsAll() {
371	PriorityQueue q = populatedQueue(SIZE);
372	PriorityQueue p = new PriorityQueue(SIZE);
373	for (int i = 0; i < SIZE; ++i) {
374	assertTrue(q.containsAll(p));
375	assertFalse(p.containsAll(q));
376	p.add(new Integer(i));
377	}
378	assertTrue(p.containsAll(q));
379	}
380
381	/**
382	* retainAll(c) retains only those elements of c and reports true if changed
383	*/
384	public void testRetainAll() {
385	PriorityQueue q = populatedQueue(SIZE);
386	PriorityQueue p = populatedQueue(SIZE);
387	for (int i = 0; i < SIZE; ++i) {
388	boolean changed = q.retainAll(p);
389	if (i == 0)
390	assertFalse(changed);
391	else
392	assertTrue(changed);
393
394	assertTrue(q.containsAll(p));
395	assertEquals(SIZE - i, q.size());
396	p.remove();
397	}
398	}
399
400	/**
401	* removeAll(c) removes only those elements of c and reports true if changed
402	*/
403	public void testRemoveAll() {
404	for (int i = 1; i < SIZE; ++i) {
405	PriorityQueue q = populatedQueue(SIZE);
406	PriorityQueue p = populatedQueue(i);
407	assertTrue(q.removeAll(p));
408	assertEquals(SIZE - i, q.size());
409	for (int j = 0; j < i; ++j) {
410	Integer x = (Integer)(p.remove());
411	assertFalse(q.contains(x));
412	}
413	}
414	}
415
416	/**
417	* toArray contains all elements
418	*/
419	public void testToArray() {
420	PriorityQueue q = populatedQueue(SIZE);
421	Object[] o = q.toArray();
422	Arrays.sort(o);
423	for (int i = 0; i < o.length; i++)
424	assertSame(o[i], q.poll());
425	}
426
427	/**
428	* toArray(a) contains all elements
429	*/
430	public void testToArray2() {
431	PriorityQueue<Integer> q = populatedQueue(SIZE);
432	Integer[] ints = new Integer[SIZE];
433	Integer[] array = q.toArray(ints);
434	assertSame(ints, array);
435	Arrays.sort(ints);
436	for (int i = 0; i < ints.length; i++)
437	assertSame(ints[i], q.poll());
438	}
439
440	/**
441	* iterator iterates through all elements
442	*/
443	public void testIterator() {
444	PriorityQueue q = populatedQueue(SIZE);
445	Iterator it = q.iterator();
446	int i;
447	for (i = 0; it.hasNext(); i++)
448	assertTrue(q.contains(it.next()));
449	assertEquals(i, SIZE);
450	assertIteratorExhausted(it);
451	}
452
453	/**
454	* iterator of empty collection has no elements
455	*/
456	public void testEmptyIterator() {
457	assertIteratorExhausted(new PriorityQueue().iterator());
458	}
459
460	/**
461	* iterator.remove removes current element
462	*/
463	public void testIteratorRemove() {
464	final PriorityQueue q = new PriorityQueue(3);
465	q.add(new Integer(2));
466	q.add(new Integer(1));
467	q.add(new Integer(3));
468
469	Iterator it = q.iterator();
470	it.next();
471	it.remove();
472
473	it = q.iterator();
474	assertEquals(it.next(), new Integer(2));
475	assertEquals(it.next(), new Integer(3));
476	assertFalse(it.hasNext());
477	}
478
479	/**
480	* toString contains toStrings of elements
481	*/
482	public void testToString() {
483	PriorityQueue q = populatedQueue(SIZE);
484	String s = q.toString();
485	for (int i = 0; i < SIZE; ++i) {
486	assertTrue(s.contains(String.valueOf(i)));
487	}
488	}
489
490	/**
491	* A deserialized serialized queue has same elements
492	*/
493	public void testSerialization() throws Exception {
494	Queue x = populatedQueue(SIZE);
495	Queue y = serialClone(x);
496
497	assertNotSame(x, y);
498	assertEquals(x.size(), y.size());
499	while (!x.isEmpty()) {
500	assertFalse(y.isEmpty());
501	assertEquals(x.remove(), y.remove());
502	}
503	assertTrue(y.isEmpty());
504	}
505	}