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.Iterator; |
12 |
import java.util.LinkedList; |
13 |
import java.util.NoSuchElementException; |
14 |
|
15 |
import junit.framework.Test; |
16 |
import junit.framework.TestSuite; |
17 |
|
18 |
public class LinkedListTest extends JSR166TestCase { |
19 |
public static void main(String[] args) { |
20 |
junit.textui.TestRunner.run(suite()); |
21 |
} |
22 |
|
23 |
public static Test suite() { |
24 |
return new TestSuite(LinkedListTest.class); |
25 |
} |
26 |
|
27 |
/** |
28 |
* Returns a new queue of given size containing consecutive |
29 |
* Integers 0 ... n. |
30 |
*/ |
31 |
private LinkedList<Integer> populatedQueue(int n) { |
32 |
LinkedList<Integer> q = new LinkedList<Integer>(); |
33 |
assertTrue(q.isEmpty()); |
34 |
for (int i = 0; i < n; ++i) |
35 |
assertTrue(q.offer(new Integer(i))); |
36 |
assertFalse(q.isEmpty()); |
37 |
assertEquals(n, q.size()); |
38 |
return q; |
39 |
} |
40 |
|
41 |
/** |
42 |
* new queue is empty |
43 |
*/ |
44 |
public void testConstructor1() { |
45 |
assertEquals(0, new LinkedList().size()); |
46 |
} |
47 |
|
48 |
/** |
49 |
* Initializing from null Collection throws NPE |
50 |
*/ |
51 |
public void testConstructor3() { |
52 |
try { |
53 |
LinkedList q = new LinkedList((Collection)null); |
54 |
shouldThrow(); |
55 |
} catch (NullPointerException success) {} |
56 |
} |
57 |
|
58 |
/** |
59 |
* Queue contains all elements of collection used to initialize |
60 |
*/ |
61 |
public void testConstructor6() { |
62 |
Integer[] ints = new Integer[SIZE]; |
63 |
for (int i = 0; i < SIZE; ++i) |
64 |
ints[i] = i; |
65 |
LinkedList q = new LinkedList(Arrays.asList(ints)); |
66 |
for (int i = 0; i < SIZE; ++i) |
67 |
assertEquals(ints[i], q.poll()); |
68 |
} |
69 |
|
70 |
/** |
71 |
* isEmpty is true before add, false after |
72 |
*/ |
73 |
public void testEmpty() { |
74 |
LinkedList q = new LinkedList(); |
75 |
assertTrue(q.isEmpty()); |
76 |
q.add(new Integer(1)); |
77 |
assertFalse(q.isEmpty()); |
78 |
q.add(new Integer(2)); |
79 |
q.remove(); |
80 |
q.remove(); |
81 |
assertTrue(q.isEmpty()); |
82 |
} |
83 |
|
84 |
/** |
85 |
* size changes when elements added and removed |
86 |
*/ |
87 |
public void testSize() { |
88 |
LinkedList q = populatedQueue(SIZE); |
89 |
for (int i = 0; i < SIZE; ++i) { |
90 |
assertEquals(SIZE-i, q.size()); |
91 |
q.remove(); |
92 |
} |
93 |
for (int i = 0; i < SIZE; ++i) { |
94 |
assertEquals(i, q.size()); |
95 |
q.add(new Integer(i)); |
96 |
} |
97 |
} |
98 |
|
99 |
/** |
100 |
* offer(null) succeeds |
101 |
*/ |
102 |
public void testOfferNull() { |
103 |
LinkedList q = new LinkedList(); |
104 |
q.offer(null); |
105 |
} |
106 |
|
107 |
/** |
108 |
* Offer succeeds |
109 |
*/ |
110 |
public void testOffer() { |
111 |
LinkedList q = new LinkedList(); |
112 |
assertTrue(q.offer(new Integer(0))); |
113 |
assertTrue(q.offer(new Integer(1))); |
114 |
} |
115 |
|
116 |
/** |
117 |
* add succeeds |
118 |
*/ |
119 |
public void testAdd() { |
120 |
LinkedList q = new LinkedList(); |
121 |
for (int i = 0; i < SIZE; ++i) { |
122 |
assertEquals(i, q.size()); |
123 |
assertTrue(q.add(new Integer(i))); |
124 |
} |
125 |
} |
126 |
|
127 |
/** |
128 |
* addAll(null) throws NPE |
129 |
*/ |
130 |
public void testAddAll1() { |
131 |
try { |
132 |
LinkedList q = new LinkedList(); |
133 |
q.addAll(null); |
134 |
shouldThrow(); |
135 |
} catch (NullPointerException success) {} |
136 |
} |
137 |
|
138 |
/** |
139 |
* Queue contains all elements, in traversal order, of successful addAll |
140 |
*/ |
141 |
public void testAddAll5() { |
142 |
Integer[] empty = new Integer[0]; |
143 |
Integer[] ints = new Integer[SIZE]; |
144 |
for (int i = 0; i < SIZE; ++i) |
145 |
ints[i] = i; |
146 |
LinkedList q = new LinkedList(); |
147 |
assertFalse(q.addAll(Arrays.asList(empty))); |
148 |
assertTrue(q.addAll(Arrays.asList(ints))); |
149 |
for (int i = 0; i < SIZE; ++i) |
150 |
assertEquals(ints[i], q.poll()); |
151 |
} |
152 |
|
153 |
/** |
154 |
* addAll with too large an index throws IOOBE |
155 |
*/ |
156 |
public void testAddAll2_IndexOutOfBoundsException() { |
157 |
LinkedList l = new LinkedList(); |
158 |
l.add(new Object()); |
159 |
LinkedList m = new LinkedList(); |
160 |
m.add(new Object()); |
161 |
try { |
162 |
l.addAll(4,m); |
163 |
shouldThrow(); |
164 |
} catch (IndexOutOfBoundsException success) {} |
165 |
} |
166 |
|
167 |
/** |
168 |
* addAll with negative index throws IOOBE |
169 |
*/ |
170 |
public void testAddAll4_BadIndex() { |
171 |
LinkedList l = new LinkedList(); |
172 |
l.add(new Object()); |
173 |
LinkedList m = new LinkedList(); |
174 |
m.add(new Object()); |
175 |
try { |
176 |
l.addAll(-1,m); |
177 |
shouldThrow(); |
178 |
} catch (IndexOutOfBoundsException success) {} |
179 |
} |
180 |
|
181 |
/** |
182 |
* poll succeeds unless empty |
183 |
*/ |
184 |
public void testPoll() { |
185 |
LinkedList q = populatedQueue(SIZE); |
186 |
for (int i = 0; i < SIZE; ++i) { |
187 |
assertEquals(i, q.poll()); |
188 |
} |
189 |
assertNull(q.poll()); |
190 |
} |
191 |
|
192 |
/** |
193 |
* peek returns next element, or null if empty |
194 |
*/ |
195 |
public void testPeek() { |
196 |
LinkedList q = populatedQueue(SIZE); |
197 |
for (int i = 0; i < SIZE; ++i) { |
198 |
assertEquals(i, q.peek()); |
199 |
assertEquals(i, q.poll()); |
200 |
assertTrue(q.peek() == null || |
201 |
!q.peek().equals(i)); |
202 |
} |
203 |
assertNull(q.peek()); |
204 |
} |
205 |
|
206 |
/** |
207 |
* element returns next element, or throws NSEE if empty |
208 |
*/ |
209 |
public void testElement() { |
210 |
LinkedList q = populatedQueue(SIZE); |
211 |
for (int i = 0; i < SIZE; ++i) { |
212 |
assertEquals(i, q.element()); |
213 |
assertEquals(i, q.poll()); |
214 |
} |
215 |
try { |
216 |
q.element(); |
217 |
shouldThrow(); |
218 |
} catch (NoSuchElementException success) {} |
219 |
} |
220 |
|
221 |
/** |
222 |
* remove removes next element, or throws NSEE if empty |
223 |
*/ |
224 |
public void testRemove() { |
225 |
LinkedList q = populatedQueue(SIZE); |
226 |
for (int i = 0; i < SIZE; ++i) { |
227 |
assertEquals(i, q.remove()); |
228 |
} |
229 |
try { |
230 |
q.remove(); |
231 |
shouldThrow(); |
232 |
} catch (NoSuchElementException success) {} |
233 |
} |
234 |
|
235 |
/** |
236 |
* remove(x) removes x and returns true if present |
237 |
*/ |
238 |
public void testRemoveElement() { |
239 |
LinkedList q = populatedQueue(SIZE); |
240 |
for (int i = 1; i < SIZE; i += 2) { |
241 |
assertTrue(q.contains(i)); |
242 |
assertTrue(q.remove((Integer)i)); |
243 |
assertFalse(q.contains(i)); |
244 |
assertTrue(q.contains(i-1)); |
245 |
} |
246 |
for (int i = 0; i < SIZE; i += 2) { |
247 |
assertTrue(q.contains(i)); |
248 |
assertTrue(q.remove((Integer)i)); |
249 |
assertFalse(q.contains(i)); |
250 |
assertFalse(q.remove((Integer)(i+1))); |
251 |
assertFalse(q.contains(i+1)); |
252 |
} |
253 |
assertTrue(q.isEmpty()); |
254 |
} |
255 |
|
256 |
/** |
257 |
* contains(x) reports true when elements added but not yet removed |
258 |
*/ |
259 |
public void testContains() { |
260 |
LinkedList q = populatedQueue(SIZE); |
261 |
for (int i = 0; i < SIZE; ++i) { |
262 |
assertTrue(q.contains(new Integer(i))); |
263 |
q.poll(); |
264 |
assertFalse(q.contains(new Integer(i))); |
265 |
} |
266 |
} |
267 |
|
268 |
/** |
269 |
* clear removes all elements |
270 |
*/ |
271 |
public void testClear() { |
272 |
LinkedList q = populatedQueue(SIZE); |
273 |
q.clear(); |
274 |
assertTrue(q.isEmpty()); |
275 |
assertEquals(0, q.size()); |
276 |
assertTrue(q.add(new Integer(1))); |
277 |
assertFalse(q.isEmpty()); |
278 |
q.clear(); |
279 |
assertTrue(q.isEmpty()); |
280 |
} |
281 |
|
282 |
/** |
283 |
* containsAll(c) is true when c contains a subset of elements |
284 |
*/ |
285 |
public void testContainsAll() { |
286 |
LinkedList q = populatedQueue(SIZE); |
287 |
LinkedList p = new LinkedList(); |
288 |
for (int i = 0; i < SIZE; ++i) { |
289 |
assertTrue(q.containsAll(p)); |
290 |
assertFalse(p.containsAll(q)); |
291 |
assertTrue(p.add(new Integer(i))); |
292 |
} |
293 |
assertTrue(p.containsAll(q)); |
294 |
} |
295 |
|
296 |
/** |
297 |
* retainAll(c) retains only those elements of c and reports true if changed |
298 |
*/ |
299 |
public void testRetainAll() { |
300 |
LinkedList q = populatedQueue(SIZE); |
301 |
LinkedList p = populatedQueue(SIZE); |
302 |
for (int i = 0; i < SIZE; ++i) { |
303 |
boolean changed = q.retainAll(p); |
304 |
if (i == 0) |
305 |
assertFalse(changed); |
306 |
else |
307 |
assertTrue(changed); |
308 |
|
309 |
assertTrue(q.containsAll(p)); |
310 |
assertEquals(SIZE-i, q.size()); |
311 |
p.remove(); |
312 |
} |
313 |
} |
314 |
|
315 |
/** |
316 |
* removeAll(c) removes only those elements of c and reports true if changed |
317 |
*/ |
318 |
public void testRemoveAll() { |
319 |
for (int i = 1; i < SIZE; ++i) { |
320 |
LinkedList q = populatedQueue(SIZE); |
321 |
LinkedList p = populatedQueue(i); |
322 |
assertTrue(q.removeAll(p)); |
323 |
assertEquals(SIZE-i, q.size()); |
324 |
for (int j = 0; j < i; ++j) { |
325 |
Integer I = (Integer)(p.remove()); |
326 |
assertFalse(q.contains(I)); |
327 |
} |
328 |
} |
329 |
} |
330 |
|
331 |
/** |
332 |
* toArray contains all elements in FIFO order |
333 |
*/ |
334 |
public void testToArray() { |
335 |
LinkedList q = populatedQueue(SIZE); |
336 |
Object[] o = q.toArray(); |
337 |
for (int i = 0; i < o.length; i++) |
338 |
assertSame(o[i], q.poll()); |
339 |
} |
340 |
|
341 |
/** |
342 |
* toArray(a) contains all elements in FIFO order |
343 |
*/ |
344 |
public void testToArray2() { |
345 |
LinkedList<Integer> q = populatedQueue(SIZE); |
346 |
Integer[] ints = new Integer[SIZE]; |
347 |
Integer[] array = q.toArray(ints); |
348 |
assertSame(ints, array); |
349 |
for (int i = 0; i < ints.length; i++) |
350 |
assertSame(ints[i], q.poll()); |
351 |
} |
352 |
|
353 |
/** |
354 |
* toArray(null) throws NullPointerException |
355 |
*/ |
356 |
public void testToArray_NullArg() { |
357 |
LinkedList l = new LinkedList(); |
358 |
l.add(new Object()); |
359 |
try { |
360 |
l.toArray(null); |
361 |
shouldThrow(); |
362 |
} catch (NullPointerException success) {} |
363 |
} |
364 |
|
365 |
/** |
366 |
* toArray(incompatible array type) throws ArrayStoreException |
367 |
*/ |
368 |
public void testToArray1_BadArg() { |
369 |
LinkedList l = new LinkedList(); |
370 |
l.add(new Integer(5)); |
371 |
try { |
372 |
l.toArray(new String[10]); |
373 |
shouldThrow(); |
374 |
} catch (ArrayStoreException success) {} |
375 |
} |
376 |
|
377 |
/** |
378 |
* iterator iterates through all elements |
379 |
*/ |
380 |
public void testIterator() { |
381 |
LinkedList q = populatedQueue(SIZE); |
382 |
int i = 0; |
383 |
Iterator it = q.iterator(); |
384 |
while (it.hasNext()) { |
385 |
assertTrue(q.contains(it.next())); |
386 |
++i; |
387 |
} |
388 |
assertEquals(i, SIZE); |
389 |
} |
390 |
|
391 |
/** |
392 |
* iterator ordering is FIFO |
393 |
*/ |
394 |
public void testIteratorOrdering() { |
395 |
final LinkedList q = new LinkedList(); |
396 |
q.add(new Integer(1)); |
397 |
q.add(new Integer(2)); |
398 |
q.add(new Integer(3)); |
399 |
int k = 0; |
400 |
for (Iterator it = q.iterator(); it.hasNext();) { |
401 |
assertEquals(++k, it.next()); |
402 |
} |
403 |
|
404 |
assertEquals(3, k); |
405 |
} |
406 |
|
407 |
/** |
408 |
* iterator.remove removes current element |
409 |
*/ |
410 |
public void testIteratorRemove() { |
411 |
final LinkedList q = new LinkedList(); |
412 |
q.add(new Integer(1)); |
413 |
q.add(new Integer(2)); |
414 |
q.add(new Integer(3)); |
415 |
Iterator it = q.iterator(); |
416 |
assertEquals(1, it.next()); |
417 |
it.remove(); |
418 |
it = q.iterator(); |
419 |
assertEquals(2, it.next()); |
420 |
assertEquals(3, it.next()); |
421 |
assertFalse(it.hasNext()); |
422 |
} |
423 |
|
424 |
/** |
425 |
* Descending iterator iterates through all elements |
426 |
*/ |
427 |
public void testDescendingIterator() { |
428 |
LinkedList q = populatedQueue(SIZE); |
429 |
int i = 0; |
430 |
Iterator it = q.descendingIterator(); |
431 |
while (it.hasNext()) { |
432 |
assertTrue(q.contains(it.next())); |
433 |
++i; |
434 |
} |
435 |
assertEquals(i, SIZE); |
436 |
assertFalse(it.hasNext()); |
437 |
try { |
438 |
it.next(); |
439 |
shouldThrow(); |
440 |
} catch (NoSuchElementException success) {} |
441 |
} |
442 |
|
443 |
/** |
444 |
* Descending iterator ordering is reverse FIFO |
445 |
*/ |
446 |
public void testDescendingIteratorOrdering() { |
447 |
final LinkedList q = new LinkedList(); |
448 |
q.add(new Integer(3)); |
449 |
q.add(new Integer(2)); |
450 |
q.add(new Integer(1)); |
451 |
int k = 0; |
452 |
for (Iterator it = q.descendingIterator(); it.hasNext();) { |
453 |
assertEquals(++k, it.next()); |
454 |
} |
455 |
|
456 |
assertEquals(3, k); |
457 |
} |
458 |
|
459 |
/** |
460 |
* descendingIterator.remove removes current element |
461 |
*/ |
462 |
public void testDescendingIteratorRemove() { |
463 |
final LinkedList q = new LinkedList(); |
464 |
q.add(three); |
465 |
q.add(two); |
466 |
q.add(one); |
467 |
Iterator it = q.descendingIterator(); |
468 |
it.next(); |
469 |
it.remove(); |
470 |
it = q.descendingIterator(); |
471 |
assertSame(it.next(), two); |
472 |
assertSame(it.next(), three); |
473 |
assertFalse(it.hasNext()); |
474 |
} |
475 |
|
476 |
/** |
477 |
* toString contains toStrings of elements |
478 |
*/ |
479 |
public void testToString() { |
480 |
LinkedList q = populatedQueue(SIZE); |
481 |
String s = q.toString(); |
482 |
for (int i = 0; i < SIZE; ++i) { |
483 |
assertTrue(s.contains(String.valueOf(i))); |
484 |
} |
485 |
} |
486 |
|
487 |
/** |
488 |
* peek returns element inserted with addFirst |
489 |
*/ |
490 |
public void testAddFirst() { |
491 |
LinkedList q = populatedQueue(3); |
492 |
q.addFirst(four); |
493 |
assertSame(four, q.peek()); |
494 |
} |
495 |
|
496 |
/** |
497 |
* peekFirst returns element inserted with push |
498 |
*/ |
499 |
public void testPush() { |
500 |
LinkedList q = populatedQueue(3); |
501 |
q.push(four); |
502 |
assertSame(four, q.peekFirst()); |
503 |
} |
504 |
|
505 |
/** |
506 |
* pop removes next element, or throws NSEE if empty |
507 |
*/ |
508 |
public void testPop() { |
509 |
LinkedList q = populatedQueue(SIZE); |
510 |
for (int i = 0; i < SIZE; ++i) { |
511 |
assertEquals(i, q.pop()); |
512 |
} |
513 |
try { |
514 |
q.pop(); |
515 |
shouldThrow(); |
516 |
} catch (NoSuchElementException success) {} |
517 |
} |
518 |
|
519 |
/** |
520 |
* OfferFirst succeeds |
521 |
*/ |
522 |
public void testOfferFirst() { |
523 |
LinkedList q = new LinkedList(); |
524 |
assertTrue(q.offerFirst(new Integer(0))); |
525 |
assertTrue(q.offerFirst(new Integer(1))); |
526 |
} |
527 |
|
528 |
/** |
529 |
* OfferLast succeeds |
530 |
*/ |
531 |
public void testOfferLast() { |
532 |
LinkedList q = new LinkedList(); |
533 |
assertTrue(q.offerLast(new Integer(0))); |
534 |
assertTrue(q.offerLast(new Integer(1))); |
535 |
} |
536 |
|
537 |
/** |
538 |
* pollLast succeeds unless empty |
539 |
*/ |
540 |
public void testPollLast() { |
541 |
LinkedList q = populatedQueue(SIZE); |
542 |
for (int i = SIZE-1; i >= 0; --i) { |
543 |
assertEquals(i, q.pollLast()); |
544 |
} |
545 |
assertNull(q.pollLast()); |
546 |
} |
547 |
|
548 |
/** |
549 |
* peekFirst returns next element, or null if empty |
550 |
*/ |
551 |
public void testPeekFirst() { |
552 |
LinkedList q = populatedQueue(SIZE); |
553 |
for (int i = 0; i < SIZE; ++i) { |
554 |
assertEquals(i, q.peekFirst()); |
555 |
assertEquals(i, q.pollFirst()); |
556 |
assertTrue(q.peekFirst() == null || |
557 |
!q.peekFirst().equals(i)); |
558 |
} |
559 |
assertNull(q.peekFirst()); |
560 |
} |
561 |
|
562 |
/** |
563 |
* peekLast returns next element, or null if empty |
564 |
*/ |
565 |
public void testPeekLast() { |
566 |
LinkedList q = populatedQueue(SIZE); |
567 |
for (int i = SIZE-1; i >= 0; --i) { |
568 |
assertEquals(i, q.peekLast()); |
569 |
assertEquals(i, q.pollLast()); |
570 |
assertTrue(q.peekLast() == null || |
571 |
!q.peekLast().equals(i)); |
572 |
} |
573 |
assertNull(q.peekLast()); |
574 |
} |
575 |
|
576 |
public void testFirstElement() { |
577 |
LinkedList q = populatedQueue(SIZE); |
578 |
for (int i = 0; i < SIZE; ++i) { |
579 |
assertEquals(i, q.getFirst()); |
580 |
assertEquals(i, q.pollFirst()); |
581 |
} |
582 |
try { |
583 |
q.getFirst(); |
584 |
shouldThrow(); |
585 |
} catch (NoSuchElementException success) {} |
586 |
} |
587 |
|
588 |
/** |
589 |
* getLast returns next element, or throws NSEE if empty |
590 |
*/ |
591 |
public void testLastElement() { |
592 |
LinkedList q = populatedQueue(SIZE); |
593 |
for (int i = SIZE-1; i >= 0; --i) { |
594 |
assertEquals(i, q.getLast()); |
595 |
assertEquals(i, q.pollLast()); |
596 |
} |
597 |
try { |
598 |
q.getLast(); |
599 |
shouldThrow(); |
600 |
} catch (NoSuchElementException success) {} |
601 |
assertNull(q.peekLast()); |
602 |
} |
603 |
|
604 |
/** |
605 |
* removeFirstOccurrence(x) removes x and returns true if present |
606 |
*/ |
607 |
public void testRemoveFirstOccurrence() { |
608 |
LinkedList q = populatedQueue(SIZE); |
609 |
for (int i = 1; i < SIZE; i += 2) { |
610 |
assertTrue(q.removeFirstOccurrence(new Integer(i))); |
611 |
} |
612 |
for (int i = 0; i < SIZE; i += 2) { |
613 |
assertTrue(q.removeFirstOccurrence(new Integer(i))); |
614 |
assertFalse(q.removeFirstOccurrence(new Integer(i+1))); |
615 |
} |
616 |
assertTrue(q.isEmpty()); |
617 |
} |
618 |
|
619 |
/** |
620 |
* removeLastOccurrence(x) removes x and returns true if present |
621 |
*/ |
622 |
public void testRemoveLastOccurrence() { |
623 |
LinkedList q = populatedQueue(SIZE); |
624 |
for (int i = 1; i < SIZE; i += 2) { |
625 |
assertTrue(q.removeLastOccurrence(new Integer(i))); |
626 |
} |
627 |
for (int i = 0; i < SIZE; i += 2) { |
628 |
assertTrue(q.removeLastOccurrence(new Integer(i))); |
629 |
assertFalse(q.removeLastOccurrence(new Integer(i+1))); |
630 |
} |
631 |
assertTrue(q.isEmpty()); |
632 |
} |
633 |
|
634 |
} |