AbstractSequentialList<E>

This class provides a skeletal implementation of the List interface to minimize the effort required to implement this interface backed by a "sequential access" data store (such as a linked list). For random access data (such as an array), AbstractList should be used in preference to this class.

This class is the opposite of the AbstractList class in the sense that it implements the "random access" methods (get(int index), set(int index, Object element), set(int index, Object element), add(int index, Object element) and remove(int index)) on top of the list's list iterator, instead of the other way around.

To implement a list the programmer needs only to extend this class and provide implementations for the listIterator and size methods. For an unmodifiable list, the programmer need only implement the list iterator's hasNext, next, hasPrevious, previous and index methods.

For a modifiable list the programmer should additionally implement the list iterator's set method. For a variable-size list the programmer should additionally implement the list iterator's remove and add methods.

The programmer should generally provide a void (no argument) and collection constructor, as per the recommendation in the Collection interface specification.

This class is a member of the Java Collections Framework.

Since: 1.2

Version: 1.31, 06/22/03

Author: Josh Bloch Neal Gafter

Constructor Summary
protected	AbstractSequentialList() Sole constructor.

Method Summary
void	add(int index, E element) Inserts the specified element at the specified position in this list.
boolean	addAll(int index, Collection<? extends E> c) Inserts all of the elements in in the specified collection into this list at the specified position.
E	get(int index) Returns the element at the specified position in this list.
Iterator<E>	iterator() Returns an iterator over the elements in this list (in proper sequence).
abstract ListIterator<E>	listIterator(int index) Returns a list iterator over the elements in this list (in proper sequence).
E	remove(int index) Removes the element at the specified position in this list.
E	set(int index, E element) Replaces the element at the specified position in this list with the specified element.

Constructor Detail

AbstractSequentialList

Sole constructor. (For invocation by subclass constructors, typically implicit.)

Method Detail

add

Inserts the specified element at the specified position in this list. Shifts the element currently at that position (if any) and any subsequent elements to the right (adds one to their indices).

This implementation first gets a list iterator pointing to the indexed element (with listIterator(index)). Then, it inserts the specified element with ListIterator.add.

Note that this implementation will throw an UnsupportedOperationException if list iterator does not implement the add operation.

Parameters: index index at which the specified element is to be inserted. element element to be inserted.

Throws: UnsupportedOperationException if the add operation is not supported by this list. NullPointerException this list does not permit null elements and one of the elements of c is null. ClassCastException if the class of the specified element prevents it from being added to this list. IllegalArgumentException if some aspect of the specified element prevents it from being added to this list. IndexOutOfBoundsException if the specified index is out of range (index < 0 || index > size()).

addAll

Inserts all of the elements in in the specified collection into this list at the specified position. Shifts the element currently at that position (if any) and any subsequent elements to the right (increases their indices). The new elements will appear in the list in the order that they are returned by the specified collection's iterator. The behavior of this operation is unspecified if the specified collection is modified while the operation is in progress. (Note that this will occur if the specified collection is this list, and it's nonempty.) Optional operation.

This implementation gets an iterator over the specified collection and a list iterator over this list pointing to the indexed element (with listIterator(index)). Then, it iterates over the specified collection, inserting the elements obtained from the iterator into this list, one at a time, using ListIterator.add followed by ListIterator.next (to skip over the added element).

Note that this implementation will throw an UnsupportedOperationException if the list iterator returned by the listIterator method does not implement the add operation.

Parameters: index index at which to insert first element from the specified collection. c elements to be inserted into this list.

Returns: true if this list changed as a result of the call.

Throws: UnsupportedOperationException if the addAll operation is not supported by this list. NullPointerException this list does not permit null elements and one of the elements of the specified collection is null. ClassCastException if the class of the specified element prevents it from being added to this list. IllegalArgumentException if some aspect of the specified element prevents it from being added to this list. IndexOutOfBoundsException if the specified index is out of range (index < 0 || index > size()). NullPointerException if the specified collection is null.

get

Returns the element at the specified position in this list.

This implementation first gets a list iterator pointing to the indexed element (with listIterator(index)). Then, it gets the element using ListIterator.next and returns it.

Parameters: index index of element to return.

Returns: the element at the specified position in this list.

Throws: IndexOutOfBoundsException if the specified index is out of range (index < 0 || index >= size()).

iterator

Returns an iterator over the elements in this list (in proper sequence).

This implementation merely returns a list iterator over the list.

Returns: an iterator over the elements in this list (in proper sequence).

listIterator

Returns a list iterator over the elements in this list (in proper sequence).

Parameters: index index of first element to be returned from the list iterator (by a call to the next method)

Returns: a list iterator over the elements in this list (in proper sequence).

remove

Removes the element at the specified position in this list. Shifts any subsequent elements to the left (subtracts one from their indices).

This implementation first gets a list iterator pointing to the indexed element (with listIterator(index)). Then, it removes the element with ListIterator.remove.

Note that this implementation will throw an UnsupportedOperationException if list iterator does not implement the remove operation.

Parameters: index index of the element to be removed from the List.

Returns: the element that was removed from the list.

Throws: UnsupportedOperationException if the remove operation is not supported by this list. IndexOutOfBoundsException if the specified index is out of range (index < 0 || index >= size()).

set

Replaces the element at the specified position in this list with the specified element.

This implementation first gets a list iterator pointing to the indexed element (with listIterator(index)). Then, it gets the current element using ListIterator.next and replaces it with ListIterator.set.

Note that this implementation will throw an UnsupportedOperationException if list iterator does not implement the set operation.

Parameters: index index of element to replace. element element to be stored at the specified position.

Returns: the element previously at the specified position.

Throws: UnsupportedOperationException set is not supported by this list. NullPointerException this list does not permit null elements and one of the elements of c is null. ClassCastException class of the specified element prevents it from being added to this list. IllegalArgumentException some aspect of the specified element prevents it from being added to this list. IndexOutOfBoundsException index out of range (index < 0 || index >= size()). IllegalArgumentException fromIndex > toIndex.

Class AbstractSequentialList<E>