AbstractSequentialList (Java 2 Platform SE 5.0) (original) (raw)

java.util

Class AbstractSequentialList

java.lang.Object extended by java.util.AbstractCollection java.util.AbstractList java.util.AbstractSequentialList

All Implemented Interfaces:

Iterable, Collection, List

Direct Known Subclasses:

LinkedList

public abstract class AbstractSequentialList

extends AbstractList

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 andadd 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

Field Summary

Fields inherited from class java.util.AbstractList
modCount

Constructor Summary
protected	AbstractSequentialList() Sole constructor.

Method Summary
void	[add](../../java/util/AbstractSequentialList.html#add%28int, E%29)(int index,E element) Inserts the specified element at the specified position in this list.
boolean	[addAll](../../java/util/AbstractSequentialList.html#addAll%28int, java.util.Collection%29)(int index,Collection<? extends E> c) Inserts all of the elements 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](../../java/util/AbstractSequentialList.html#set%28int, E%29)(int index,E element) Replaces the element at the specified position in this list with the specified element.

Methods inherited from class java.util.AbstractList
add, clear, equals, hashCode, indexOf, lastIndexOf, listIterator, [removeRange](../../java/util/AbstractList.html#removeRange%28int, int%29), [subList](../../java/util/AbstractList.html#subList%28int, int%29)

Methods inherited from class java.util.AbstractCollection
addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, size, toArray, toArray, toString

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, [wait](../../java/lang/Object.html#wait%28long, int%29)

Methods inherited from interface java.util.List
addAll, contains, containsAll, isEmpty, remove, removeAll, retainAll, size, toArray, toArray

Constructor Detail

AbstractSequentialList

protected AbstractSequentialList()

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

Method Detail

get

public E get(int index)

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.

Specified by:

[get](../../java/util/List.html#get%28int%29) in interface [List](../../java/util/List.html "interface in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Specified by:

[get](../../java/util/AbstractList.html#get%28int%29) in class [AbstractList](../../java/util/AbstractList.html "class in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Parameters:

index - index of element to return.

Returns:

the element at the specified position in this list.

Throws:

[IndexOutOfBoundsException](../../java/lang/IndexOutOfBoundsException.html "class in java.lang") - if the specified index is out of range (index < 0 || index >= size()).

set

public E set(int index, E element)

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.

Specified by:

[set](../../java/util/List.html#set%28int, E%29) in interface [List](../../java/util/List.html "interface in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Overrides:

[set](../../java/util/AbstractList.html#set%28int, E%29) in class [AbstractList](../../java/util/AbstractList.html "class in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

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](../../java/lang/UnsupportedOperationException.html "class in java.lang") - set is not supported by this list.

[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang") - this list does not permit null elements and one of the elements of c is null.

[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang") - class of the specified element prevents it from being added to this list.

[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang") - some aspect of the specified element prevents it from being added to this list.

[IndexOutOfBoundsException](../../java/lang/IndexOutOfBoundsException.html "class in java.lang") - index out of range(index < 0 || index >= size()).

[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang") - fromIndex > toIndex.

add

public void add(int index, E element)

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 anUnsupportedOperationException if list iterator does not implement the add operation.

Specified by:

[add](../../java/util/List.html#add%28int, E%29) in interface [List](../../java/util/List.html "interface in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Overrides:

[add](../../java/util/AbstractList.html#add%28int, E%29) in class [AbstractList](../../java/util/AbstractList.html "class in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Parameters:

index - index at which the specified element is to be inserted.

element - element to be inserted.

Throws:

[UnsupportedOperationException](../../java/lang/UnsupportedOperationException.html "class in java.lang") - if the add operation is not supported by this list.

[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang") - this list does not permit null elements and one of the elements of c isnull.

[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang") - if the class of the specified element prevents it from being added to this list.

[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang") - if some aspect of the specified element prevents it from being added to this list.

[IndexOutOfBoundsException](../../java/lang/IndexOutOfBoundsException.html "class in java.lang") - if the specified index is out of range (index < 0 || index > size()).

remove

public E remove(int index)

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 anUnsupportedOperationException if list iterator does not implement the remove operation.

Specified by:

[remove](../../java/util/List.html#remove%28int%29) in interface [List](../../java/util/List.html "interface in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Overrides:

[remove](../../java/util/AbstractList.html#remove%28int%29) in class [AbstractList](../../java/util/AbstractList.html "class in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Parameters:

index - index of the element to be removed from the List.

Returns:

the element that was removed from the list.

Throws:

[UnsupportedOperationException](../../java/lang/UnsupportedOperationException.html "class in java.lang") - if the remove operation is not supported by this list.

[IndexOutOfBoundsException](../../java/lang/IndexOutOfBoundsException.html "class in java.lang") - if the specified index is out of range (index < 0 || index >= size()).

addAll

public boolean addAll(int index, Collection<? extends E> c)

Inserts all of the elements 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 (withlistIterator(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 byListIterator.next (to skip over the added element).

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

Specified by:

[addAll](../../java/util/List.html#addAll%28int, java.util.Collection%29) in interface [List](../../java/util/List.html "interface in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Overrides:

[addAll](../../java/util/AbstractList.html#addAll%28int, java.util.Collection%29) in class [AbstractList](../../java/util/AbstractList.html "class in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

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](../../java/lang/UnsupportedOperationException.html "class in java.lang") - if the addAll operation is not supported by this list.

[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang") - this list does not permit null elements and one of the elements of the specified collection is null.

[ClassCastException](../../java/lang/ClassCastException.html "class in java.lang") - if the class of the specified element prevents it from being added to this list.

[IllegalArgumentException](../../java/lang/IllegalArgumentException.html "class in java.lang") - if some aspect of the specified element prevents it from being added to this list.

[IndexOutOfBoundsException](../../java/lang/IndexOutOfBoundsException.html "class in java.lang") - if the specified index is out of range (index < 0 || index > size()).

[NullPointerException](../../java/lang/NullPointerException.html "class in java.lang") - if the specified collection is null.

iterator

public Iterator<E> iterator()

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

This implementation merely returns a list iterator over the list.

Specified by:

[iterator](../../java/lang/Iterable.html#iterator%28%29) in interface [Iterable](../../java/lang/Iterable.html "interface in java.lang")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Specified by:

[iterator](../../java/util/Collection.html#iterator%28%29) in interface [Collection](../../java/util/Collection.html "interface in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Specified by:

[iterator](../../java/util/List.html#iterator%28%29) in interface [List](../../java/util/List.html "interface in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Overrides:

[iterator](../../java/util/AbstractList.html#iterator%28%29) in class [AbstractList](../../java/util/AbstractList.html "class in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Returns:

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

See Also:

AbstractList.modCount

listIterator

public abstract ListIterator<E> listIterator(int index)

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

Specified by:

[listIterator](../../java/util/List.html#listIterator%28int%29) in interface [List](../../java/util/List.html "interface in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

Overrides:

[listIterator](../../java/util/AbstractList.html#listIterator%28int%29) in class [AbstractList](../../java/util/AbstractList.html "class in java.util")<[E](../../java/util/AbstractSequentialList.html "type parameter in AbstractSequentialList")>

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).

See Also:

AbstractList.modCount

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