How to use

iterator

method

in

com.twelvemonkeys.util.CollectionUtil

  protected Iterator<String> keysImpl() {
    @SuppressWarnings("unchecked")
    Enumeration<String> headerNames = request.getHeaderNames();
    return headerNames == null ? null : CollectionUtil.iterator(headerNames);
  }
}

protected List<String> valueImpl(final String pName) {
  @SuppressWarnings("unchecked")
  Enumeration<String> headers = request.getHeaders(pName);
  return headers == null ? null : toList(CollectionUtil.iterator(headers));
}

/**
 * Creates a thin {@link Iterator} wrapper around an array.
 *
 * @param pArray the array to iterate
 * @return a new {@link ListIterator}
 * @throws IllegalArgumentException if {@code pArray} is {@code null},
 *         {@code pStart < 0}, or
 *         {@code pLength > pArray.length - pStart}
 */
public static <E> ListIterator<E> iterator(final E[] pArray) {
  return iterator(pArray, 0, notNull(pArray).length);
}

  protected Iterator<String> keysImpl() {
    @SuppressWarnings("unchecked")
    Enumeration<String> names = request.getParameterNames();
    return names == null ? null : CollectionUtil.iterator(names);
  }
}

@Test(expected = IllegalArgumentException.class)
public void testArrayIteratorRangeBadStart() {
  CollectionUtil.iterator(stringObjects, stringObjects.length + 1, 2);
}
@Test(expected = IllegalArgumentException.class)

@Test(expected = IllegalArgumentException.class)
public void testArrayIteratorNull() {
  CollectionUtil.iterator((Object[]) null);
}

@Test(expected = IllegalArgumentException.class)
public void testEnumIteratorNull() {
  CollectionUtil.iterator((Enumeration<Object>) null);
}

@Test(expected = IllegalArgumentException.class)
public void testArrayIteratorRangeBadLength() {
  CollectionUtil.iterator(stringObjects, 1, stringObjects.length);
}

@Test(expected = IllegalArgumentException.class)
public void testArrayIteratorRangeNull() {
  CollectionUtil.iterator(null, 0, 0);
}

@Test
public void testArrayListIterator() {
  assertCorrectListIterator(CollectionUtil.iterator(new String[] {"foo", "bar", "baz"}), stringObjects);
}

@Test
public void testArrayListIteratorRange() {
  assertCorrectListIterator(CollectionUtil.iterator(new String[] {"foo", "bar", "baz", "boo"}, 1, 2), new String[] {"bar", "baz"});
}

@Test
public void testEmptyIteratorConstructor() throws IOException {
  Reader reader = new CompoundReader(CollectionUtil.iterator(new Reader[0]));
  assertEquals(-1, reader.read());
}

  @Test
  public void testIteratorWithNullConstructor() throws IOException {
    try {
      new CompoundReader(CollectionUtil.iterator(new Reader[] {null}));
      fail("Should not allow null in iterator argument");
    }
    catch (RuntimeException e) {
      assertNotNull(e.getMessage());
    }
  }
}

@Test
public void testArrayIteratorRange() {
  Iterator<String> iterator = CollectionUtil.iterator(new String[] {"foo", "bar", "baz", "xyzzy"}, 1, 2);
  for (int i = 1; i < 3; i++) {
    assertTrue(iterator.hasNext());
    assertEquals(stringObjects[i], iterator.next());
    try {
      iterator.remove();
      fail("Array has no remove method, iterator.remove() must throw exception");
    }
    catch (UnsupportedOperationException expected) {
    }
  }
  assertFalse(iterator.hasNext());
  try {
    iterator.next();
    fail("Iterator has more elements than array range");
  }
  catch (NoSuchElementException expected) {
  }
}

@Test
public void testEnumIterator() {
  @SuppressWarnings("unchecked")
  Iterator<String> iterator = CollectionUtil.iterator((Enumeration) new StringTokenizer("foo, bar, baz", ", "));
  int count = 0;
  for (Object stringObject : stringObjects) {
    assertTrue(iterator.hasNext());
    assertEquals(stringObject, iterator.next());
    
    try {
      iterator.remove();
      fail("Enumeration has no remove method, iterator.remove() must throw exception");
    }
    catch (UnsupportedOperationException expected) {
    }
    count++;
  }
  assertEquals(3, count);
  assertFalse(iterator.hasNext());
  
  try {
    iterator.next();
    fail("Iterator has more elements than enumeration");
  }
  catch (NoSuchElementException expected) {
  }
}

@Test
public void testArrayIterator() {
  Iterator<String> iterator = CollectionUtil.iterator(new String[] {"foo", "bar", "baz"});
  int count = 0;
  for (Object stringObject : stringObjects) {
    assertTrue(iterator.hasNext());
    assertEquals(stringObject, iterator.next());
    try {
      iterator.remove();
      fail("Array have fixed length, iterator.remove() must throw exception");
    }
    catch (UnsupportedOperationException expected) {
    }
    count++;
  }
  assertEquals(3, count);
  assertFalse(iterator.hasNext());
  try {
    iterator.next();
    fail("Iterator has more elements than array");
  }
  catch (NoSuchElementException expected) {
  }
}

/**
 * Creates a thin {@link Iterator} wrapper around an array.
 *
 * @param pArray the array to iterate
 * @return a new {@link ListIterator}
 * @throws IllegalArgumentException if {@code pArray} is {@code null},
 *         {@code pStart < 0}, or
 *         {@code pLength > pArray.length - pStart}
 */
public static <E> ListIterator<E> iterator(final E[] pArray) {
  return iterator(pArray, 0, notNull(pArray).length);
}

@Test(expected = IllegalArgumentException.class)
public void testArrayIteratorRangeBadLength() {
  CollectionUtil.iterator(stringObjects, 1, stringObjects.length);
}

@Test
public void testEmptyIteratorConstructor() throws IOException {
  Reader reader = new CompoundReader(CollectionUtil.iterator(new Reader[0]));
  assertEquals(-1, reader.read());
}

  @Test
  public void testIteratorWithNullConstructor() throws IOException {
    try {
      new CompoundReader(CollectionUtil.iterator(new Reader[] {null}));
      fail("Should not allow null in iterator argument");
    }
    catch (RuntimeException e) {
      assertNotNull(e.getMessage());
    }
  }
}