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;

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; }
        }
        class ComparatorImplementation implements CollectionImplementation {
            public Class<?> klazz() { return PriorityQueue.class; }
            public Collection emptyCollection() { return new PriorityQueue(new MyReverseComparator()); }
            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()),
                            CollectionTest.testSuite(new ComparatorImplementation()));
    }

    static class MyReverseComparator implements Comparator, java.io.Serializable {
        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 static 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 IllegalArgumentException 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/reserialized 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:	1.45
Committed:	Sun May 6 22:09:42 2018 UTC (5 years, 11 months ago) by jsr166
Branch:	MAIN
Changes since 1.44:	+10 -2 lines
Log Message:	Add tests for PriorityQueue with Comparator
#	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
19	public class PriorityQueueTest extends JSR166TestCase {
20	public static void main(String[] args) {
21	main(suite(), args);
22	}
23	public static Test suite() {
24	class Implementation implements CollectionImplementation {
25	public Class<?> klazz() { return PriorityQueue.class; }
26	public Collection emptyCollection() { return new PriorityQueue(); }
27	public Object makeElement(int i) { return i; }
28	public boolean isConcurrent() { return false; }
29	public boolean permitsNulls() { return false; }
30	}
31	class ComparatorImplementation implements CollectionImplementation {
32	public Class<?> klazz() { return PriorityQueue.class; }
33	public Collection emptyCollection() { return new PriorityQueue(new MyReverseComparator()); }
34	public Object makeElement(int i) { return i; }
35	public boolean isConcurrent() { return false; }
36	public boolean permitsNulls() { return false; }
37	}
38	return newTestSuite(PriorityQueueTest.class,
39	CollectionTest.testSuite(new Implementation()),
40	CollectionTest.testSuite(new ComparatorImplementation()));
41	}
42
43	static class MyReverseComparator implements Comparator, java.io.Serializable {
44	public int compare(Object x, Object y) {
45	return ((Comparable)y).compareTo(x);
46	}
47	}
48
49	/**
50	* Returns a new queue of given size containing consecutive
51	* Integers 0 ... n - 1.
52	*/
53	private static PriorityQueue<Integer> populatedQueue(int n) {
54	PriorityQueue<Integer> q = new PriorityQueue<>(n);
55	assertTrue(q.isEmpty());
56	for (int i = n - 1; i >= 0; i -= 2)
57	assertTrue(q.offer(new Integer(i)));
58	for (int i = (n & 1); i < n; i += 2)
59	assertTrue(q.offer(new Integer(i)));
60	assertFalse(q.isEmpty());
61	assertEquals(n, q.size());
62	assertEquals((Integer) 0, q.peek());
63	return q;
64	}
65
66	/**
67	* A new queue has unbounded capacity
68	*/
69	public void testConstructor1() {
70	assertEquals(0, new PriorityQueue(SIZE).size());
71	}
72
73	/**
74	* Constructor throws IllegalArgumentException if capacity argument nonpositive
75	*/
76	public void testConstructor2() {
77	try {
78	new PriorityQueue(0);
79	shouldThrow();
80	} catch (IllegalArgumentException success) {}
81	}
82
83	/**
84	* Initializing from null Collection throws NPE
85	*/
86	public void testConstructor3() {
87	try {
88	new PriorityQueue((Collection)null);
89	shouldThrow();
90	} catch (NullPointerException success) {}
91	}
92
93	/**
94	* Initializing from Collection of null elements throws NPE
95	*/
96	public void testConstructor4() {
97	try {
98	new PriorityQueue(Arrays.asList(new Integer[SIZE]));
99	shouldThrow();
100	} catch (NullPointerException success) {}
101	}
102
103	/**
104	* Initializing from Collection with some null elements throws NPE
105	*/
106	public void testConstructor5() {
107	Integer[] ints = new Integer[SIZE];
108	for (int i = 0; i < SIZE - 1; ++i)
109	ints[i] = new Integer(i);
110	try {
111	new PriorityQueue(Arrays.asList(ints));
112	shouldThrow();
113	} catch (NullPointerException success) {}
114	}
115
116	/**
117	* Queue contains all elements of collection used to initialize
118	*/
119	public void testConstructor6() {
120	Integer[] ints = new Integer[SIZE];
121	for (int i = 0; i < SIZE; ++i)
122	ints[i] = new Integer(i);
123	PriorityQueue q = new PriorityQueue(Arrays.asList(ints));
124	for (int i = 0; i < SIZE; ++i)
125	assertEquals(ints[i], q.poll());
126	}
127
128	/**
129	* The comparator used in constructor is used
130	*/
131	public void testConstructor7() {
132	MyReverseComparator cmp = new MyReverseComparator();
133	PriorityQueue q = new PriorityQueue(SIZE, cmp);
134	assertEquals(cmp, q.comparator());
135	Integer[] ints = new Integer[SIZE];
136	for (int i = 0; i < SIZE; ++i)
137	ints[i] = new Integer(i);
138	q.addAll(Arrays.asList(ints));
139	for (int i = SIZE - 1; i >= 0; --i)
140	assertEquals(ints[i], q.poll());
141	}
142
143	/**
144	* isEmpty is true before add, false after
145	*/
146	public void testEmpty() {
147	PriorityQueue q = new PriorityQueue(2);
148	assertTrue(q.isEmpty());
149	q.add(new Integer(1));
150	assertFalse(q.isEmpty());
151	q.add(new Integer(2));
152	q.remove();
153	q.remove();
154	assertTrue(q.isEmpty());
155	}
156
157	/**
158	* size changes when elements added and removed
159	*/
160	public void testSize() {
161	PriorityQueue q = populatedQueue(SIZE);
162	for (int i = 0; i < SIZE; ++i) {
163	assertEquals(SIZE - i, q.size());
164	q.remove();
165	}
166	for (int i = 0; i < SIZE; ++i) {
167	assertEquals(i, q.size());
168	q.add(new Integer(i));
169	}
170	}
171
172	/**
173	* offer(null) throws NPE
174	*/
175	public void testOfferNull() {
176	PriorityQueue q = new PriorityQueue(1);
177	try {
178	q.offer(null);
179	shouldThrow();
180	} catch (NullPointerException success) {}
181	}
182
183	/**
184	* add(null) throws NPE
185	*/
186	public void testAddNull() {
187	PriorityQueue q = new PriorityQueue(1);
188	try {
189	q.add(null);
190	shouldThrow();
191	} catch (NullPointerException success) {}
192	}
193
194	/**
195	* Offer of comparable element succeeds
196	*/
197	public void testOffer() {
198	PriorityQueue q = new PriorityQueue(1);
199	assertTrue(q.offer(zero));
200	assertTrue(q.offer(one));
201	}
202
203	/**
204	* Offer of non-Comparable throws CCE
205	*/
206	public void testOfferNonComparable() {
207	PriorityQueue q = new PriorityQueue(1);
208	try {
209	q.offer(new Object());
210	shouldThrow();
211	} catch (ClassCastException success) {
212	assertTrue(q.isEmpty());
213	assertEquals(0, q.size());
214	assertNull(q.poll());
215	}
216	}
217
218	/**
219	* add of comparable succeeds
220	*/
221	public void testAdd() {
222	PriorityQueue q = new PriorityQueue(SIZE);
223	for (int i = 0; i < SIZE; ++i) {
224	assertEquals(i, q.size());
225	assertTrue(q.add(new Integer(i)));
226	}
227	}
228
229	/**
230	* addAll(null) throws NPE
231	*/
232	public void testAddAll1() {
233	PriorityQueue q = new PriorityQueue(1);
234	try {
235	q.addAll(null);
236	shouldThrow();
237	} catch (NullPointerException success) {}
238	}
239
240	/**
241	* addAll of a collection with null elements throws NPE
242	*/
243	public void testAddAll2() {
244	PriorityQueue q = new PriorityQueue(SIZE);
245	try {
246	q.addAll(Arrays.asList(new Integer[SIZE]));
247	shouldThrow();
248	} catch (NullPointerException success) {}
249	}
250
251	/**
252	* addAll of a collection with any null elements throws NPE after
253	* possibly adding some elements
254	*/
255	public void testAddAll3() {
256	PriorityQueue q = new PriorityQueue(SIZE);
257	Integer[] ints = new Integer[SIZE];
258	for (int i = 0; i < SIZE - 1; ++i)
259	ints[i] = new Integer(i);
260	try {
261	q.addAll(Arrays.asList(ints));
262	shouldThrow();
263	} catch (NullPointerException success) {}
264	}
265
266	/**
267	* Queue contains all elements of successful addAll
268	*/
269	public void testAddAll5() {
270	Integer[] empty = new Integer[0];
271	Integer[] ints = new Integer[SIZE];
272	for (int i = 0; i < SIZE; ++i)
273	ints[i] = new Integer(SIZE - 1 - i);
274	PriorityQueue q = new PriorityQueue(SIZE);
275	assertFalse(q.addAll(Arrays.asList(empty)));
276	assertTrue(q.addAll(Arrays.asList(ints)));
277	for (int i = 0; i < SIZE; ++i)
278	assertEquals(new Integer(i), q.poll());
279	}
280
281	/**
282	* poll succeeds unless empty
283	*/
284	public void testPoll() {
285	PriorityQueue q = populatedQueue(SIZE);
286	for (int i = 0; i < SIZE; ++i) {
287	assertEquals(i, q.poll());
288	}
289	assertNull(q.poll());
290	}
291
292	/**
293	* peek returns next element, or null if empty
294	*/
295	public void testPeek() {
296	PriorityQueue q = populatedQueue(SIZE);
297	for (int i = 0; i < SIZE; ++i) {
298	assertEquals(i, q.peek());
299	assertEquals(i, q.poll());
300	assertTrue(q.peek() == null \|\|
301	!q.peek().equals(i));
302	}
303	assertNull(q.peek());
304	}
305
306	/**
307	* element returns next element, or throws NSEE if empty
308	*/
309	public void testElement() {
310	PriorityQueue q = populatedQueue(SIZE);
311	for (int i = 0; i < SIZE; ++i) {
312	assertEquals(i, q.element());
313	assertEquals(i, q.poll());
314	}
315	try {
316	q.element();
317	shouldThrow();
318	} catch (NoSuchElementException success) {}
319	}
320
321	/**
322	* remove removes next element, or throws NSEE if empty
323	*/
324	public void testRemove() {
325	PriorityQueue q = populatedQueue(SIZE);
326	for (int i = 0; i < SIZE; ++i) {
327	assertEquals(i, q.remove());
328	}
329	try {
330	q.remove();
331	shouldThrow();
332	} catch (NoSuchElementException success) {}
333	}
334
335	/**
336	* remove(x) removes x and returns true if present
337	*/
338	public void testRemoveElement() {
339	PriorityQueue q = populatedQueue(SIZE);
340	for (int i = 1; i < SIZE; i += 2) {
341	assertTrue(q.contains(i));
342	assertTrue(q.remove(i));
343	assertFalse(q.contains(i));
344	assertTrue(q.contains(i - 1));
345	}
346	for (int i = 0; i < SIZE; i += 2) {
347	assertTrue(q.contains(i));
348	assertTrue(q.remove(i));
349	assertFalse(q.contains(i));
350	assertFalse(q.remove(i + 1));
351	assertFalse(q.contains(i + 1));
352	}
353	assertTrue(q.isEmpty());
354	}
355
356	/**
357	* contains(x) reports true when elements added but not yet removed
358	*/
359	public void testContains() {
360	PriorityQueue q = populatedQueue(SIZE);
361	for (int i = 0; i < SIZE; ++i) {
362	assertTrue(q.contains(new Integer(i)));
363	q.poll();
364	assertFalse(q.contains(new Integer(i)));
365	}
366	}
367
368	/**
369	* clear removes all elements
370	*/
371	public void testClear() {
372	PriorityQueue q = populatedQueue(SIZE);
373	q.clear();
374	assertTrue(q.isEmpty());
375	assertEquals(0, q.size());
376	q.add(new Integer(1));
377	assertFalse(q.isEmpty());
378	q.clear();
379	assertTrue(q.isEmpty());
380	}
381
382	/**
383	* containsAll(c) is true when c contains a subset of elements
384	*/
385	public void testContainsAll() {
386	PriorityQueue q = populatedQueue(SIZE);
387	PriorityQueue p = new PriorityQueue(SIZE);
388	for (int i = 0; i < SIZE; ++i) {
389	assertTrue(q.containsAll(p));
390	assertFalse(p.containsAll(q));
391	p.add(new Integer(i));
392	}
393	assertTrue(p.containsAll(q));
394	}
395
396	/**
397	* retainAll(c) retains only those elements of c and reports true if changed
398	*/
399	public void testRetainAll() {
400	PriorityQueue q = populatedQueue(SIZE);
401	PriorityQueue p = populatedQueue(SIZE);
402	for (int i = 0; i < SIZE; ++i) {
403	boolean changed = q.retainAll(p);
404	if (i == 0)
405	assertFalse(changed);
406	else
407	assertTrue(changed);
408
409	assertTrue(q.containsAll(p));
410	assertEquals(SIZE - i, q.size());
411	p.remove();
412	}
413	}
414
415	/**
416	* removeAll(c) removes only those elements of c and reports true if changed
417	*/
418	public void testRemoveAll() {
419	for (int i = 1; i < SIZE; ++i) {
420	PriorityQueue q = populatedQueue(SIZE);
421	PriorityQueue p = populatedQueue(i);
422	assertTrue(q.removeAll(p));
423	assertEquals(SIZE - i, q.size());
424	for (int j = 0; j < i; ++j) {
425	Integer x = (Integer)(p.remove());
426	assertFalse(q.contains(x));
427	}
428	}
429	}
430
431	/**
432	* toArray contains all elements
433	*/
434	public void testToArray() {
435	PriorityQueue q = populatedQueue(SIZE);
436	Object[] o = q.toArray();
437	Arrays.sort(o);
438	for (int i = 0; i < o.length; i++)
439	assertSame(o[i], q.poll());
440	}
441
442	/**
443	* toArray(a) contains all elements
444	*/
445	public void testToArray2() {
446	PriorityQueue<Integer> q = populatedQueue(SIZE);
447	Integer[] ints = new Integer[SIZE];
448	Integer[] array = q.toArray(ints);
449	assertSame(ints, array);
450	Arrays.sort(ints);
451	for (int i = 0; i < ints.length; i++)
452	assertSame(ints[i], q.poll());
453	}
454
455	/**
456	* iterator iterates through all elements
457	*/
458	public void testIterator() {
459	PriorityQueue q = populatedQueue(SIZE);
460	Iterator it = q.iterator();
461	int i;
462	for (i = 0; it.hasNext(); i++)
463	assertTrue(q.contains(it.next()));
464	assertEquals(i, SIZE);
465	assertIteratorExhausted(it);
466	}
467
468	/**
469	* iterator of empty collection has no elements
470	*/
471	public void testEmptyIterator() {
472	assertIteratorExhausted(new PriorityQueue().iterator());
473	}
474
475	/**
476	* iterator.remove removes current element
477	*/
478	public void testIteratorRemove() {
479	final PriorityQueue q = new PriorityQueue(3);
480	q.add(new Integer(2));
481	q.add(new Integer(1));
482	q.add(new Integer(3));
483
484	Iterator it = q.iterator();
485	it.next();
486	it.remove();
487
488	it = q.iterator();
489	assertEquals(it.next(), new Integer(2));
490	assertEquals(it.next(), new Integer(3));
491	assertFalse(it.hasNext());
492	}
493
494	/**
495	* toString contains toStrings of elements
496	*/
497	public void testToString() {
498	PriorityQueue q = populatedQueue(SIZE);
499	String s = q.toString();
500	for (int i = 0; i < SIZE; ++i) {
501	assertTrue(s.contains(String.valueOf(i)));
502	}
503	}
504
505	/**
506	* A deserialized/reserialized queue has same elements
507	*/
508	public void testSerialization() throws Exception {
509	Queue x = populatedQueue(SIZE);
510	Queue y = serialClone(x);
511
512	assertNotSame(x, y);
513	assertEquals(x.size(), y.size());
514	while (!x.isEmpty()) {
515	assertFalse(y.isEmpty());
516	assertEquals(x.remove(), y.remove());
517	}
518	assertTrue(y.isEmpty());
519	}
520	}