| /* |
| * 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. |
| */ |
| |
| package jsr166; |
| |
| import java.util.Arrays; |
| import java.util.Collection; |
| import java.util.Iterator; |
| import java.util.LinkedList; |
| import java.util.NoSuchElementException; |
| |
| import junit.framework.Test; |
| import junit.framework.TestSuite; |
| |
| public class LinkedListTest extends JSR166TestCase { |
| // android-note: Removed because the CTS runner does a bad job of |
| // retrying tests that have suite() declarations. |
| // |
| // public static void main(String[] args) { |
| // main(suite(), args); |
| // } |
| // public static Test suite() { |
| // return new TestSuite(LinkedListTest.class); |
| // } |
| |
| /** |
| * Returns a new queue of given size containing consecutive |
| * Integers 0 ... n. |
| */ |
| private LinkedList<Integer> populatedQueue(int n) { |
| LinkedList<Integer> q = new LinkedList<Integer>(); |
| assertTrue(q.isEmpty()); |
| for (int i = 0; i < n; ++i) |
| assertTrue(q.offer(new Integer(i))); |
| assertFalse(q.isEmpty()); |
| assertEquals(n, q.size()); |
| return q; |
| } |
| |
| /** |
| * new queue is empty |
| */ |
| public void testConstructor1() { |
| assertEquals(0, new LinkedList().size()); |
| } |
| |
| /** |
| * Initializing from null Collection throws NPE |
| */ |
| public void testConstructor3() { |
| try { |
| new LinkedList((Collection)null); |
| 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] = i; |
| LinkedList q = new LinkedList(Arrays.asList(ints)); |
| for (int i = 0; i < SIZE; ++i) |
| assertEquals(ints[i], q.poll()); |
| } |
| |
| /** |
| * isEmpty is true before add, false after |
| */ |
| public void testEmpty() { |
| LinkedList q = new LinkedList(); |
| 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() { |
| LinkedList 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) succeeds |
| */ |
| public void testOfferNull() { |
| LinkedList q = new LinkedList(); |
| q.offer(null); |
| assertNull(q.get(0)); |
| assertTrue(q.contains(null)); |
| } |
| |
| /** |
| * Offer succeeds |
| */ |
| public void testOffer() { |
| LinkedList q = new LinkedList(); |
| assertTrue(q.offer(new Integer(0))); |
| assertTrue(q.offer(new Integer(1))); |
| } |
| |
| /** |
| * add succeeds |
| */ |
| public void testAdd() { |
| LinkedList q = new LinkedList(); |
| for (int i = 0; i < SIZE; ++i) { |
| assertEquals(i, q.size()); |
| assertTrue(q.add(new Integer(i))); |
| } |
| } |
| |
| /** |
| * addAll(null) throws NPE |
| */ |
| public void testAddAll1() { |
| LinkedList q = new LinkedList(); |
| try { |
| q.addAll(null); |
| shouldThrow(); |
| } catch (NullPointerException success) {} |
| } |
| |
| /** |
| * Queue contains all elements, in traversal order, 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] = i; |
| LinkedList q = new LinkedList(); |
| assertFalse(q.addAll(Arrays.asList(empty))); |
| assertTrue(q.addAll(Arrays.asList(ints))); |
| for (int i = 0; i < SIZE; ++i) |
| assertEquals(ints[i], q.poll()); |
| } |
| |
| /** |
| * addAll with too large an index throws IOOBE |
| */ |
| public void testAddAll2_IndexOutOfBoundsException() { |
| LinkedList l = new LinkedList(); |
| l.add(new Object()); |
| LinkedList m = new LinkedList(); |
| m.add(new Object()); |
| try { |
| l.addAll(4,m); |
| shouldThrow(); |
| } catch (IndexOutOfBoundsException success) {} |
| } |
| |
| /** |
| * addAll with negative index throws IOOBE |
| */ |
| public void testAddAll4_BadIndex() { |
| LinkedList l = new LinkedList(); |
| l.add(new Object()); |
| LinkedList m = new LinkedList(); |
| m.add(new Object()); |
| try { |
| l.addAll(-1,m); |
| shouldThrow(); |
| } catch (IndexOutOfBoundsException success) {} |
| } |
| |
| /** |
| * poll succeeds unless empty |
| */ |
| public void testPoll() { |
| LinkedList 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() { |
| LinkedList 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() { |
| LinkedList 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() { |
| LinkedList 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() { |
| LinkedList q = populatedQueue(SIZE); |
| for (int i = 1; i < SIZE; i += 2) { |
| assertTrue(q.contains(i)); |
| assertTrue(q.remove((Integer)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((Integer)i)); |
| assertFalse(q.contains(i)); |
| assertFalse(q.remove((Integer)(i + 1))); |
| assertFalse(q.contains(i + 1)); |
| } |
| assertTrue(q.isEmpty()); |
| } |
| |
| /** |
| * contains(x) reports true when elements added but not yet removed |
| */ |
| public void testContains() { |
| LinkedList 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() { |
| LinkedList q = populatedQueue(SIZE); |
| q.clear(); |
| assertTrue(q.isEmpty()); |
| assertEquals(0, q.size()); |
| assertTrue(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() { |
| LinkedList q = populatedQueue(SIZE); |
| LinkedList p = new LinkedList(); |
| for (int i = 0; i < SIZE; ++i) { |
| assertTrue(q.containsAll(p)); |
| assertFalse(p.containsAll(q)); |
| assertTrue(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() { |
| LinkedList q = populatedQueue(SIZE); |
| LinkedList 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) { |
| LinkedList q = populatedQueue(SIZE); |
| LinkedList 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 in FIFO order |
| */ |
| public void testToArray() { |
| LinkedList q = populatedQueue(SIZE); |
| Object[] o = q.toArray(); |
| for (int i = 0; i < o.length; i++) |
| assertSame(o[i], q.poll()); |
| } |
| |
| /** |
| * toArray(a) contains all elements in FIFO order |
| */ |
| public void testToArray2() { |
| LinkedList<Integer> q = populatedQueue(SIZE); |
| Integer[] ints = new Integer[SIZE]; |
| Integer[] array = q.toArray(ints); |
| assertSame(ints, array); |
| for (int i = 0; i < ints.length; i++) |
| assertSame(ints[i], q.poll()); |
| } |
| |
| /** |
| * toArray(null) throws NullPointerException |
| */ |
| public void testToArray_NullArg() { |
| LinkedList l = new LinkedList(); |
| l.add(new Object()); |
| try { |
| l.toArray(null); |
| shouldThrow(); |
| } catch (NullPointerException success) {} |
| } |
| |
| /** |
| * toArray(incompatible array type) throws ArrayStoreException |
| */ |
| public void testToArray1_BadArg() { |
| LinkedList l = new LinkedList(); |
| l.add(new Integer(5)); |
| try { |
| l.toArray(new String[10]); |
| shouldThrow(); |
| } catch (ArrayStoreException success) {} |
| } |
| |
| /** |
| * iterator iterates through all elements |
| */ |
| public void testIterator() { |
| LinkedList 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 LinkedList().iterator()); |
| } |
| |
| /** |
| * iterator ordering is FIFO |
| */ |
| public void testIteratorOrdering() { |
| final LinkedList q = new LinkedList(); |
| q.add(new Integer(1)); |
| q.add(new Integer(2)); |
| q.add(new Integer(3)); |
| int k = 0; |
| for (Iterator it = q.iterator(); it.hasNext();) { |
| assertEquals(++k, it.next()); |
| } |
| |
| assertEquals(3, k); |
| } |
| |
| /** |
| * iterator.remove removes current element |
| */ |
| public void testIteratorRemove() { |
| final LinkedList q = new LinkedList(); |
| q.add(new Integer(1)); |
| q.add(new Integer(2)); |
| q.add(new Integer(3)); |
| Iterator it = q.iterator(); |
| assertEquals(1, it.next()); |
| it.remove(); |
| it = q.iterator(); |
| assertEquals(2, it.next()); |
| assertEquals(3, it.next()); |
| assertFalse(it.hasNext()); |
| } |
| |
| /** |
| * Descending iterator iterates through all elements |
| */ |
| public void testDescendingIterator() { |
| LinkedList q = populatedQueue(SIZE); |
| int i = 0; |
| Iterator it = q.descendingIterator(); |
| while (it.hasNext()) { |
| assertTrue(q.contains(it.next())); |
| ++i; |
| } |
| assertEquals(i, SIZE); |
| assertFalse(it.hasNext()); |
| try { |
| it.next(); |
| shouldThrow(); |
| } catch (NoSuchElementException success) {} |
| } |
| |
| /** |
| * Descending iterator ordering is reverse FIFO |
| */ |
| public void testDescendingIteratorOrdering() { |
| final LinkedList q = new LinkedList(); |
| q.add(new Integer(3)); |
| q.add(new Integer(2)); |
| q.add(new Integer(1)); |
| int k = 0; |
| for (Iterator it = q.descendingIterator(); it.hasNext();) { |
| assertEquals(++k, it.next()); |
| } |
| |
| assertEquals(3, k); |
| } |
| |
| /** |
| * descendingIterator.remove removes current element |
| */ |
| public void testDescendingIteratorRemove() { |
| final LinkedList q = new LinkedList(); |
| q.add(three); |
| q.add(two); |
| q.add(one); |
| Iterator it = q.descendingIterator(); |
| it.next(); |
| it.remove(); |
| it = q.descendingIterator(); |
| assertSame(it.next(), two); |
| assertSame(it.next(), three); |
| assertFalse(it.hasNext()); |
| } |
| |
| /** |
| * toString contains toStrings of elements |
| */ |
| public void testToString() { |
| LinkedList q = populatedQueue(SIZE); |
| String s = q.toString(); |
| for (int i = 0; i < SIZE; ++i) { |
| assertTrue(s.contains(String.valueOf(i))); |
| } |
| } |
| |
| /** |
| * peek returns element inserted with addFirst |
| */ |
| public void testAddFirst() { |
| LinkedList q = populatedQueue(3); |
| q.addFirst(four); |
| assertSame(four, q.peek()); |
| } |
| |
| /** |
| * peekFirst returns element inserted with push |
| */ |
| public void testPush() { |
| LinkedList q = populatedQueue(3); |
| q.push(four); |
| assertSame(four, q.peekFirst()); |
| } |
| |
| /** |
| * pop removes next element, or throws NSEE if empty |
| */ |
| public void testPop() { |
| LinkedList q = populatedQueue(SIZE); |
| for (int i = 0; i < SIZE; ++i) { |
| assertEquals(i, q.pop()); |
| } |
| try { |
| q.pop(); |
| shouldThrow(); |
| } catch (NoSuchElementException success) {} |
| } |
| |
| /** |
| * OfferFirst succeeds |
| */ |
| public void testOfferFirst() { |
| LinkedList q = new LinkedList(); |
| assertTrue(q.offerFirst(new Integer(0))); |
| assertTrue(q.offerFirst(new Integer(1))); |
| } |
| |
| /** |
| * OfferLast succeeds |
| */ |
| public void testOfferLast() { |
| LinkedList q = new LinkedList(); |
| assertTrue(q.offerLast(new Integer(0))); |
| assertTrue(q.offerLast(new Integer(1))); |
| } |
| |
| /** |
| * pollLast succeeds unless empty |
| */ |
| public void testPollLast() { |
| LinkedList q = populatedQueue(SIZE); |
| for (int i = SIZE - 1; i >= 0; --i) { |
| assertEquals(i, q.pollLast()); |
| } |
| assertNull(q.pollLast()); |
| } |
| |
| /** |
| * peekFirst returns next element, or null if empty |
| */ |
| public void testPeekFirst() { |
| LinkedList q = populatedQueue(SIZE); |
| for (int i = 0; i < SIZE; ++i) { |
| assertEquals(i, q.peekFirst()); |
| assertEquals(i, q.pollFirst()); |
| assertTrue(q.peekFirst() == null || |
| !q.peekFirst().equals(i)); |
| } |
| assertNull(q.peekFirst()); |
| } |
| |
| /** |
| * peekLast returns next element, or null if empty |
| */ |
| public void testPeekLast() { |
| LinkedList q = populatedQueue(SIZE); |
| for (int i = SIZE - 1; i >= 0; --i) { |
| assertEquals(i, q.peekLast()); |
| assertEquals(i, q.pollLast()); |
| assertTrue(q.peekLast() == null || |
| !q.peekLast().equals(i)); |
| } |
| assertNull(q.peekLast()); |
| } |
| |
| public void testFirstElement() { |
| LinkedList q = populatedQueue(SIZE); |
| for (int i = 0; i < SIZE; ++i) { |
| assertEquals(i, q.getFirst()); |
| assertEquals(i, q.pollFirst()); |
| } |
| try { |
| q.getFirst(); |
| shouldThrow(); |
| } catch (NoSuchElementException success) {} |
| } |
| |
| /** |
| * getLast returns next element, or throws NSEE if empty |
| */ |
| public void testLastElement() { |
| LinkedList q = populatedQueue(SIZE); |
| for (int i = SIZE - 1; i >= 0; --i) { |
| assertEquals(i, q.getLast()); |
| assertEquals(i, q.pollLast()); |
| } |
| try { |
| q.getLast(); |
| shouldThrow(); |
| } catch (NoSuchElementException success) {} |
| assertNull(q.peekLast()); |
| } |
| |
| /** |
| * removeFirstOccurrence(x) removes x and returns true if present |
| */ |
| public void testRemoveFirstOccurrence() { |
| LinkedList q = populatedQueue(SIZE); |
| for (int i = 1; i < SIZE; i += 2) { |
| assertTrue(q.removeFirstOccurrence(new Integer(i))); |
| } |
| for (int i = 0; i < SIZE; i += 2) { |
| assertTrue(q.removeFirstOccurrence(new Integer(i))); |
| assertFalse(q.removeFirstOccurrence(new Integer(i + 1))); |
| } |
| assertTrue(q.isEmpty()); |
| } |
| |
| /** |
| * removeLastOccurrence(x) removes x and returns true if present |
| */ |
| public void testRemoveLastOccurrence() { |
| LinkedList q = populatedQueue(SIZE); |
| for (int i = 1; i < SIZE; i += 2) { |
| assertTrue(q.removeLastOccurrence(new Integer(i))); |
| } |
| for (int i = 0; i < SIZE; i += 2) { |
| assertTrue(q.removeLastOccurrence(new Integer(i))); |
| assertFalse(q.removeLastOccurrence(new Integer(i + 1))); |
| } |
| assertTrue(q.isEmpty()); |
| } |
| |
| } |