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() {
        class Implementation implements CollectionImplementation {
            public Class<?> klazz() { return PriorityQueue.class; }
            public Collection emptyCollection() { return new PriorityQueue(); }
            public Object makeElement(int i) { return i; }
            public boolean isConcurrent() { return false; }
            public boolean permitsNulls() { return false; }
        }
        return newTestSuite(PriorityQueueTest.class,
                            CollectionTest.testSuite(new Implementation()));
    }

    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<>(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:	1.40
Committed:	Wed Jan 4 06:09:58 2017 UTC (7 years, 4 months ago) by jsr166
Branch:	MAIN
Changes since 1.39:	+1 -1 lines
Log Message:	convert to Diamond
#	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	class Implementation implements CollectionImplementation {
26	public Class<?> klazz() { return PriorityQueue.class; }
27	public Collection emptyCollection() { return new PriorityQueue(); }
28	public Object makeElement(int i) { return i; }
29	public boolean isConcurrent() { return false; }
30	public boolean permitsNulls() { return false; }
31	}
32	return newTestSuite(PriorityQueueTest.class,
33	CollectionTest.testSuite(new Implementation()));
34	}
35
36	static class MyReverseComparator implements Comparator {
37	public int compare(Object x, Object y) {
38	return ((Comparable)y).compareTo(x);
39	}
40	}
41
42	/**
43	* Returns a new queue of given size containing consecutive
44	* Integers 0 ... n - 1.
45	*/
46	private PriorityQueue<Integer> populatedQueue(int n) {
47	PriorityQueue<Integer> q = new PriorityQueue<>(n);
48	assertTrue(q.isEmpty());
49	for (int i = n - 1; i >= 0; i -= 2)
50	assertTrue(q.offer(new Integer(i)));
51	for (int i = (n & 1); i < n; i += 2)
52	assertTrue(q.offer(new Integer(i)));
53	assertFalse(q.isEmpty());
54	assertEquals(n, q.size());
55	assertEquals((Integer) 0, q.peek());
56	return q;
57	}
58
59	/**
60	* A new queue has unbounded capacity
61	*/
62	public void testConstructor1() {
63	assertEquals(0, new PriorityQueue(SIZE).size());
64	}
65
66	/**
67	* Constructor throws IAE if capacity argument nonpositive
68	*/
69	public void testConstructor2() {
70	try {
71	new PriorityQueue(0);
72	shouldThrow();
73	} catch (IllegalArgumentException success) {}
74	}
75
76	/**
77	* Initializing from null Collection throws NPE
78	*/
79	public void testConstructor3() {
80	try {
81	new PriorityQueue((Collection)null);
82	shouldThrow();
83	} catch (NullPointerException success) {}
84	}
85
86	/**
87	* Initializing from Collection of null elements throws NPE
88	*/
89	public void testConstructor4() {
90	try {
91	new PriorityQueue(Arrays.asList(new Integer[SIZE]));
92	shouldThrow();
93	} catch (NullPointerException success) {}
94	}
95
96	/**
97	* Initializing from Collection with some null elements throws NPE
98	*/
99	public void testConstructor5() {
100	Integer[] ints = new Integer[SIZE];
101	for (int i = 0; i < SIZE - 1; ++i)
102	ints[i] = new Integer(i);
103	try {
104	new PriorityQueue(Arrays.asList(ints));
105	shouldThrow();
106	} catch (NullPointerException success) {}
107	}
108
109	/**
110	* Queue contains all elements of collection used to initialize
111	*/
112	public void testConstructor6() {
113	Integer[] ints = new Integer[SIZE];
114	for (int i = 0; i < SIZE; ++i)
115	ints[i] = new Integer(i);
116	PriorityQueue q = new PriorityQueue(Arrays.asList(ints));
117	for (int i = 0; i < SIZE; ++i)
118	assertEquals(ints[i], q.poll());
119	}
120
121	/**
122	* The comparator used in constructor is used
123	*/
124	public void testConstructor7() {
125	MyReverseComparator cmp = new MyReverseComparator();
126	PriorityQueue q = new PriorityQueue(SIZE, cmp);
127	assertEquals(cmp, q.comparator());
128	Integer[] ints = new Integer[SIZE];
129	for (int i = 0; i < SIZE; ++i)
130	ints[i] = new Integer(i);
131	q.addAll(Arrays.asList(ints));
132	for (int i = SIZE - 1; i >= 0; --i)
133	assertEquals(ints[i], q.poll());
134	}
135
136	/**
137	* isEmpty is true before add, false after
138	*/
139	public void testEmpty() {
140	PriorityQueue q = new PriorityQueue(2);
141	assertTrue(q.isEmpty());
142	q.add(new Integer(1));
143	assertFalse(q.isEmpty());
144	q.add(new Integer(2));
145	q.remove();
146	q.remove();
147	assertTrue(q.isEmpty());
148	}
149
150	/**
151	* size changes when elements added and removed
152	*/
153	public void testSize() {
154	PriorityQueue q = populatedQueue(SIZE);
155	for (int i = 0; i < SIZE; ++i) {
156	assertEquals(SIZE - i, q.size());
157	q.remove();
158	}
159	for (int i = 0; i < SIZE; ++i) {
160	assertEquals(i, q.size());
161	q.add(new Integer(i));
162	}
163	}
164
165	/**
166	* offer(null) throws NPE
167	*/
168	public void testOfferNull() {
169	PriorityQueue q = new PriorityQueue(1);
170	try {
171	q.offer(null);
172	shouldThrow();
173	} catch (NullPointerException success) {}
174	}
175
176	/**
177	* add(null) throws NPE
178	*/
179	public void testAddNull() {
180	PriorityQueue q = new PriorityQueue(1);
181	try {
182	q.add(null);
183	shouldThrow();
184	} catch (NullPointerException success) {}
185	}
186
187	/**
188	* Offer of comparable element succeeds
189	*/
190	public void testOffer() {
191	PriorityQueue q = new PriorityQueue(1);
192	assertTrue(q.offer(zero));
193	assertTrue(q.offer(one));
194	}
195
196	/**
197	* Offer of non-Comparable throws CCE
198	*/
199	public void testOfferNonComparable() {
200	PriorityQueue q = new PriorityQueue(1);
201	try {
202	q.offer(new Object());
203	shouldThrow();
204	} catch (ClassCastException success) {
205	assertTrue(q.isEmpty());
206	assertEquals(0, q.size());
207	assertNull(q.poll());
208	}
209	}
210
211	/**
212	* add of comparable succeeds
213	*/
214	public void testAdd() {
215	PriorityQueue q = new PriorityQueue(SIZE);
216	for (int i = 0; i < SIZE; ++i) {
217	assertEquals(i, q.size());
218	assertTrue(q.add(new Integer(i)));
219	}
220	}
221
222	/**
223	* addAll(null) throws NPE
224	*/
225	public void testAddAll1() {
226	PriorityQueue q = new PriorityQueue(1);
227	try {
228	q.addAll(null);
229	shouldThrow();
230	} catch (NullPointerException success) {}
231	}
232
233	/**
234	* addAll of a collection with null elements throws NPE
235	*/
236	public void testAddAll2() {
237	PriorityQueue q = new PriorityQueue(SIZE);
238	try {
239	q.addAll(Arrays.asList(new Integer[SIZE]));
240	shouldThrow();
241	} catch (NullPointerException success) {}
242	}
243
244	/**
245	* addAll of a collection with any null elements throws NPE after
246	* possibly adding some elements
247	*/
248	public void testAddAll3() {
249	PriorityQueue q = new PriorityQueue(SIZE);
250	Integer[] ints = new Integer[SIZE];
251	for (int i = 0; i < SIZE - 1; ++i)
252	ints[i] = new Integer(i);
253	try {
254	q.addAll(Arrays.asList(ints));
255	shouldThrow();
256	} catch (NullPointerException success) {}
257	}
258
259	/**
260	* Queue contains all elements of successful addAll
261	*/
262	public void testAddAll5() {
263	Integer[] empty = new Integer[0];
264	Integer[] ints = new Integer[SIZE];
265	for (int i = 0; i < SIZE; ++i)
266	ints[i] = new Integer(SIZE - 1 - i);
267	PriorityQueue q = new PriorityQueue(SIZE);
268	assertFalse(q.addAll(Arrays.asList(empty)));
269	assertTrue(q.addAll(Arrays.asList(ints)));
270	for (int i = 0; i < SIZE; ++i)
271	assertEquals(new Integer(i), q.poll());
272	}
273
274	/**
275	* poll succeeds unless empty
276	*/
277	public void testPoll() {
278	PriorityQueue q = populatedQueue(SIZE);
279	for (int i = 0; i < SIZE; ++i) {
280	assertEquals(i, q.poll());
281	}
282	assertNull(q.poll());
283	}
284
285	/**
286	* peek returns next element, or null if empty
287	*/
288	public void testPeek() {
289	PriorityQueue q = populatedQueue(SIZE);
290	for (int i = 0; i < SIZE; ++i) {
291	assertEquals(i, q.peek());
292	assertEquals(i, q.poll());
293	assertTrue(q.peek() == null \|\|
294	!q.peek().equals(i));
295	}
296	assertNull(q.peek());
297	}
298
299	/**
300	* element returns next element, or throws NSEE if empty
301	*/
302	public void testElement() {
303	PriorityQueue q = populatedQueue(SIZE);
304	for (int i = 0; i < SIZE; ++i) {
305	assertEquals(i, q.element());
306	assertEquals(i, q.poll());
307	}
308	try {
309	q.element();
310	shouldThrow();
311	} catch (NoSuchElementException success) {}
312	}
313
314	/**
315	* remove removes next element, or throws NSEE if empty
316	*/
317	public void testRemove() {
318	PriorityQueue q = populatedQueue(SIZE);
319	for (int i = 0; i < SIZE; ++i) {
320	assertEquals(i, q.remove());
321	}
322	try {
323	q.remove();
324	shouldThrow();
325	} catch (NoSuchElementException success) {}
326	}
327
328	/**
329	* remove(x) removes x and returns true if present
330	*/
331	public void testRemoveElement() {
332	PriorityQueue q = populatedQueue(SIZE);
333	for (int i = 1; i < SIZE; i += 2) {
334	assertTrue(q.contains(i));
335	assertTrue(q.remove(i));
336	assertFalse(q.contains(i));
337	assertTrue(q.contains(i - 1));
338	}
339	for (int i = 0; i < SIZE; i += 2) {
340	assertTrue(q.contains(i));
341	assertTrue(q.remove(i));
342	assertFalse(q.contains(i));
343	assertFalse(q.remove(i + 1));
344	assertFalse(q.contains(i + 1));
345	}
346	assertTrue(q.isEmpty());
347	}
348
349	/**
350	* contains(x) reports true when elements added but not yet removed
351	*/
352	public void testContains() {
353	PriorityQueue q = populatedQueue(SIZE);
354	for (int i = 0; i < SIZE; ++i) {
355	assertTrue(q.contains(new Integer(i)));
356	q.poll();
357	assertFalse(q.contains(new Integer(i)));
358	}
359	}
360
361	/**
362	* clear removes all elements
363	*/
364	public void testClear() {
365	PriorityQueue q = populatedQueue(SIZE);
366	q.clear();
367	assertTrue(q.isEmpty());
368	assertEquals(0, q.size());
369	q.add(new Integer(1));
370	assertFalse(q.isEmpty());
371	q.clear();
372	assertTrue(q.isEmpty());
373	}
374
375	/**
376	* containsAll(c) is true when c contains a subset of elements
377	*/
378	public void testContainsAll() {
379	PriorityQueue q = populatedQueue(SIZE);
380	PriorityQueue p = new PriorityQueue(SIZE);
381	for (int i = 0; i < SIZE; ++i) {
382	assertTrue(q.containsAll(p));
383	assertFalse(p.containsAll(q));
384	p.add(new Integer(i));
385	}
386	assertTrue(p.containsAll(q));
387	}
388
389	/**
390	* retainAll(c) retains only those elements of c and reports true if changed
391	*/
392	public void testRetainAll() {
393	PriorityQueue q = populatedQueue(SIZE);
394	PriorityQueue p = populatedQueue(SIZE);
395	for (int i = 0; i < SIZE; ++i) {
396	boolean changed = q.retainAll(p);
397	if (i == 0)
398	assertFalse(changed);
399	else
400	assertTrue(changed);
401
402	assertTrue(q.containsAll(p));
403	assertEquals(SIZE - i, q.size());
404	p.remove();
405	}
406	}
407
408	/**
409	* removeAll(c) removes only those elements of c and reports true if changed
410	*/
411	public void testRemoveAll() {
412	for (int i = 1; i < SIZE; ++i) {
413	PriorityQueue q = populatedQueue(SIZE);
414	PriorityQueue p = populatedQueue(i);
415	assertTrue(q.removeAll(p));
416	assertEquals(SIZE - i, q.size());
417	for (int j = 0; j < i; ++j) {
418	Integer x = (Integer)(p.remove());
419	assertFalse(q.contains(x));
420	}
421	}
422	}
423
424	/**
425	* toArray contains all elements
426	*/
427	public void testToArray() {
428	PriorityQueue q = populatedQueue(SIZE);
429	Object[] o = q.toArray();
430	Arrays.sort(o);
431	for (int i = 0; i < o.length; i++)
432	assertSame(o[i], q.poll());
433	}
434
435	/**
436	* toArray(a) contains all elements
437	*/
438	public void testToArray2() {
439	PriorityQueue<Integer> q = populatedQueue(SIZE);
440	Integer[] ints = new Integer[SIZE];
441	Integer[] array = q.toArray(ints);
442	assertSame(ints, array);
443	Arrays.sort(ints);
444	for (int i = 0; i < ints.length; i++)
445	assertSame(ints[i], q.poll());
446	}
447
448	/**
449	* iterator iterates through all elements
450	*/
451	public void testIterator() {
452	PriorityQueue q = populatedQueue(SIZE);
453	Iterator it = q.iterator();
454	int i;
455	for (i = 0; it.hasNext(); i++)
456	assertTrue(q.contains(it.next()));
457	assertEquals(i, SIZE);
458	assertIteratorExhausted(it);
459	}
460
461	/**
462	* iterator of empty collection has no elements
463	*/
464	public void testEmptyIterator() {
465	assertIteratorExhausted(new PriorityQueue().iterator());
466	}
467
468	/**
469	* iterator.remove removes current element
470	*/
471	public void testIteratorRemove() {
472	final PriorityQueue q = new PriorityQueue(3);
473	q.add(new Integer(2));
474	q.add(new Integer(1));
475	q.add(new Integer(3));
476
477	Iterator it = q.iterator();
478	it.next();
479	it.remove();
480
481	it = q.iterator();
482	assertEquals(it.next(), new Integer(2));
483	assertEquals(it.next(), new Integer(3));
484	assertFalse(it.hasNext());
485	}
486
487	/**
488	* toString contains toStrings of elements
489	*/
490	public void testToString() {
491	PriorityQueue q = populatedQueue(SIZE);
492	String s = q.toString();
493	for (int i = 0; i < SIZE; ++i) {
494	assertTrue(s.contains(String.valueOf(i)));
495	}
496	}
497
498	/**
499	* A deserialized serialized queue has same elements
500	*/
501	public void testSerialization() throws Exception {
502	Queue x = populatedQueue(SIZE);
503	Queue y = serialClone(x);
504
505	assertNotSame(x, y);
506	assertEquals(x.size(), y.size());
507	while (!x.isEmpty()) {
508	assertFalse(y.isEmpty());
509	assertEquals(x.remove(), y.remove());
510	}
511	assertTrue(y.isEmpty());
512	}
513	}