java.util.NavigableSet# iterator ( ) 源码实例Demo

void mutateSet(NavigableSet<Integer> set, int min, int max, BitSet bs) {
    int size = set.size();
    int rangeSize = max - min + 1;

    // Remove a bunch of entries directly
    for (int i = 0, n = rangeSize / 2; i < n; i++) {
        remove(set, min - 5 + rnd.nextInt(rangeSize + 10), bs);
    }

    // Remove a bunch of entries with iterator
    for (Iterator<Integer> it = set.iterator(); it.hasNext(); ) {
        if (rnd.nextBoolean()) {
            bs.clear(it.next());
            it.remove();
        }
    }

    // Add entries till we're back to original size
    while (set.size() < size) {
        int element = min + rnd.nextInt(rangeSize);
        assertTrue(element >= min && element <= max);
        put(set, element, bs);
    }
}
 

private static void demoNavigableSetIterRemove(NavigableSet<Integer> set) {
    System.out.println("set: " + set);
    try {
        Iterator iter = set.iterator();
        while (iter.hasNext()) {
            Integer e = (Integer) iter.next();
            System.out.println(e);
            if (e == 2) {
                System.out.println("Calling iter.remove()...");
                iter.remove();
            }
        }
    } catch (Exception ex) {
        System.out.println(ex.getClass().getName());
    }
    System.out.println("set: " + set);
}
 

void mutateSet(NavigableSet<Integer> set, int min, int max, BitSet bs) {
    int size = set.size();
    int rangeSize = max - min + 1;

    // Remove a bunch of entries directly
    for (int i = 0, n = rangeSize / 2; i < n; i++) {
        remove(set, min - 5 + rnd.nextInt(rangeSize + 10), bs);
    }

    // Remove a bunch of entries with iterator
    for (Iterator<Integer> it = set.iterator(); it.hasNext(); ) {
        if (rnd.nextBoolean()) {
            int val = it.next();
            bs.clear(val);
            it.remove();
        }
    }

    // Add entries till we're back to original size
    while (set.size() < size) {
        int element = min + rnd.nextInt(rangeSize);
        assertTrue(element >= min && element<= max);
        put(set, element, bs);
    }
}
 

/**
 * iterator.remove removes current element
 */
public void testDescendingIteratorRemove() {
    final NavigableSet q = dset0();
    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());
}
 

/**
 * iterator.remove removes current element
 */
public void testDescendingIteratorRemove() {
    final NavigableSet q = dset0();
    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(2, it.next());
    assertEquals(3, it.next());
    assertFalse(it.hasNext());
}
 

/**
 * iterator.remove removes current element
 */
public void testIteratorRemove() {
    final NavigableSet q = set0();
    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(2, it.next());
    assertEquals(3, it.next());
    assertFalse(it.hasNext());
}
 

/**
 * Tests that the iterator is empty.
 */
@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
public void testEmptyIterator(String description, NavigableSet<?> navigableSet) {
    Iterator emptyIterator = navigableSet.iterator();

    assertFalse((emptyIterator != null) && (emptyIterator.hasNext()),
        "The iterator is not empty.");
}
 

void mutateSubSet(NavigableSet<Integer> set, int min, int max,
                  BitSet bs) {
    int size = set.size();
    int rangeSize = max - min + 1;

    // Remove a bunch of entries directly
    for (int i = 0, n = rangeSize / 2; i < n; i++) {
        remove(set, min - 5 + rnd.nextInt(rangeSize + 10), bs);
    }

    // Remove a bunch of entries with iterator
    for (Iterator<Integer> it = set.iterator(); it.hasNext(); ) {
        if (rnd.nextBoolean()) {
            bs.clear(it.next());
            it.remove();
        }
    }

    // Add entries till we're back to original size
    while (set.size() < size) {
        int element = min - 5 + rnd.nextInt(rangeSize + 10);
        if (element >= min && element <= max) {
            put(set, element, bs);
        } else {
            try {
                set.add(element);
                shouldThrow();
            } catch (IllegalArgumentException success) {}
        }
    }
}
 

/**
 * iterator of empty set has no elements
 */
public void testDescendingEmptyIterator() {
    NavigableSet q = dset0();
    int i = 0;
    Iterator it = q.iterator();
    while (it.hasNext()) {
        assertTrue(q.contains(it.next()));
        ++i;
    }
    assertEquals(0, i);
}
 

/**
 * Tests that the iterator is empty.
 */
@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
public void testEmptyIterator(String description, NavigableSet<?> navigableSet) {
    Iterator emptyIterator = navigableSet.iterator();

    assertFalse((emptyIterator != null) && (emptyIterator.hasNext()),
        "The iterator is not empty.");
}
 

/**
 * Tests that the iterator is empty.
 */
@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
public void testEmptyIterator(String description, NavigableSet<?> navigableSet) {
    Iterator emptyIterator = navigableSet.iterator();

    assertFalse((emptyIterator != null) && (emptyIterator.hasNext()),
        "The iterator is not empty.");
}
 

/**
 * iterator of empty set has no elements
 */
public void testDescendingEmptyIterator() {
    NavigableSet q = dset0();
    int i = 0;
    Iterator it = q.iterator();
    while (it.hasNext()) {
        assertTrue(q.contains(it.next()));
        ++i;
    }
    assertEquals(0, i);
}
 

/**
 * iterator of empty set has no elements
 */
public void testDescendingEmptyIterator() {
    NavigableSet q = dset0();
    int i = 0;
    Iterator it = q.iterator();
    while (it.hasNext()) {
        assertTrue(q.contains(it.next()));
        ++i;
    }
    assertEquals(0, i);
}
 

/**
 * Tests that the iterator is empty.
 */
@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
public void testEmptyIterator(String description, NavigableSet<?> navigableSet) {
    Iterator emptyIterator = navigableSet.iterator();

    assertFalse((emptyIterator != null) && (emptyIterator.hasNext()),
        "The iterator is not empty.");
}
 

/**
 * iterator of empty set has no elements
 */
public void testDescendingEmptyIterator() {
    NavigableSet q = dset0();
    int i = 0;
    Iterator it = q.iterator();
    while (it.hasNext()) {
        assertTrue(q.contains(it.next()));
        ++i;
    }
    assertEquals(0, i);
}
 

/**
 * iterator iterates through all elements
 */
public void testIterator() {
    NavigableSet q = populatedSet(SIZE);
    int i = 0;
    Iterator it = q.iterator();
    while (it.hasNext()) {
        assertTrue(q.contains(it.next()));
        ++i;
    }
    assertEquals(i, SIZE);
}
 

/**
 * iterator iterates through all elements
 */
public void testDescendingIterator() {
    NavigableSet q = populatedSet(SIZE);
    int i = 0;
    Iterator it = q.iterator();
    while (it.hasNext()) {
        assertTrue(q.contains(it.next()));
        ++i;
    }
    assertEquals(i, SIZE);
}
 

/**
 * iterator iterates through all elements
 */
public void testIterator() {
    NavigableSet q = populatedSet(SIZE);
    int i = 0;
    Iterator it = q.iterator();
    while (it.hasNext()) {
        assertTrue(q.contains(it.next()));
        ++i;
    }
    assertEquals(i, SIZE);
}
 

/**
 * iterator iterates through all elements
 */
public void testDescendingIterator() {
    NavigableSet q = populatedSet(SIZE);
    int i = 0;
    Iterator it = q.iterator();
    while (it.hasNext()) {
        assertTrue(q.contains(it.next()));
        ++i;
    }
    assertEquals(i, SIZE);
}
 

/**
 * Tests that the iterator is empty.
 */
@Test(dataProvider = "NavigableSet<?>", dataProviderClass = EmptyNavigableSet.class)
public void testEmptyIterator(String description, NavigableSet<?> navigableSet) {
    Iterator emptyIterator = navigableSet.iterator();

    assertFalse((emptyIterator != null) && (emptyIterator.hasNext()),
        "The iterator is not empty.");
}