get, set, add, and
- * remove) atop the list iterator, opposite of AbstractList's
- * approach of implementing the iterator atop random access.
- *
- *
- * To implement a list, you need an implementation for size()
- * and listIterator. With just hasNext,
- * next, hasPrevious, previous,
- * nextIndex, and previousIndex, you have an
- * unmodifiable list. For a modifiable one, add set, and for
- * a variable-size list, add add and remove.
- *
- *
- * The programmer should provide a no-argument constructor, and one that
- * accepts another Collection, as recommended by the Collection interface.
- * Unfortunately, there is no way to enforce this in Java.
- *
- * @author Original author unknown
- * @author Bryce McKinlay
- * @author Eric Blake
- *
- * This implementation grabs listIterator(index), then proceeds to use add
- * for each element returned by c's iterator. Sun's online specs are wrong,
- * claiming that this also calls next(): listIterator.add() correctly
- * skips the added element.
- *
- * @param index the location to insert the collection
- * @param c the collection to insert
- * @return true if the list was modified by this action, that is, if c is
- * non-empty
- * @throws UnsupportedOperationException if this list does not support the
- * addAll operation
- * @throws IndexOutOfBoundsException if index < 0 || index > size()
- * @throws ClassCastException if some element of c cannot be added to this
- * list due to its type
- * @throws IllegalArgumentException if some element of c cannot be added
- * to this list for some other reason
- * @throws NullPointerException if the specified collection is null
- * @see #add(int, Object)
- */
- public boolean addAll(int index, Collection c)
- {
- Iterator ci = c.iterator();
- int size = c.size();
- ListIterator i = listIterator(index);
- for (int pos = size; pos > 0; pos--)
- i.add(ci.next());
- return size > 0;
- }
-
- /**
- * Get the element at a given index in this list. This implementation
- * returns listIterator(index).next().
- *
- * @param index the index of the element to be returned
- * @return the element at index index in this list
- * @throws IndexOutOfBoundsException if index < 0 || index >= size()
- */
- public Object get(int index)
- {
- // This is a legal listIterator position, but an illegal get.
- if (index == size())
- throw new IndexOutOfBoundsException("Index: " + index + ", Size:"
- + size());
- return listIterator(index).next();
- }
-
- /**
- * Obtain an Iterator over this list, whose sequence is the list order. This
- * implementation returns listIterator().
- *
- * @return an Iterator over the elements of this list, in order
- */
- public Iterator iterator()
- {
- return listIterator();
- }
-
- /**
- * Remove the element at a given position in this list (optional operation).
- * Shifts all remaining elements to the left to fill the gap. This
- * implementation uses listIterator(index) and ListIterator.remove().
- *
- * @param index the position within the list of the object to remove
- * @return the object that was removed
- * @throws UnsupportedOperationException if this list does not support the
- * remove operation
- * @throws IndexOutOfBoundsException if index < 0 || index >= size()
- */
- public Object remove(int index)
- {
- // This is a legal listIterator position, but an illegal remove.
- if (index == size())
- throw new IndexOutOfBoundsException("Index: " + index + ", Size:"
- + size());
- ListIterator i = listIterator(index);
- Object removed = i.next();
- i.remove();
- return removed;
- }
-
- /**
- * Replace an element of this list with another object (optional operation).
- * This implementation uses listIterator(index) and ListIterator.set(o).
- *
- * @param index the position within this list of the element to be replaced
- * @param o the object to replace it with
- * @return the object that was replaced
- * @throws UnsupportedOperationException if this list does not support the
- * set operation
- * @throws IndexOutOfBoundsException if index < 0 || index >= size()
- * @throws ClassCastException if o cannot be added to this list due to its
- * type
- * @throws IllegalArgumentException if o cannot be added to this list for
- * some other reason
- */
- public Object set(int index, Object o)
- {
- // This is a legal listIterator position, but an illegal set.
- if (index == size())
- throw new IndexOutOfBoundsException("Index: " + index + ", Size:"
- + size());
- ListIterator i = listIterator(index);
- Object old = i.next();
- i.set(o);
- return old;
- }
-}