public abstract class

AbstractList

extends AbstractCollection<E>
implements List<E>

java.lang.Object
↳	java.util.AbstractCollection<E>
	↳	java.util.AbstractList<E>

Known Direct Subclasses

AbstractSequentialList<E>, ArrayList<E>, Vector<E>

Known Indirect Subclasses

LinkedList<E>, Stack<E>

Class Overview

AbstractList is an abstract implementation of the List interface, optimized for a backing store which supports random access. This implementation does not support adding or replacing. A subclass must implement the abstract methods get() and size(), and to create a modifiable List it's necessary to override the add() method that currently throws an UnsupportedOperationException.

Summary

Fields
protected int	modCount	A counter for changes to the list.

Protected Constructors
	AbstractList() Constructs a new instance of this AbstractList.

Public Methods
void	add(int location, E object) Inserts the specified object into this List at the specified location.
boolean	add(E object) Adds the specified object at the end of this List.
boolean	addAll(int location, Collection<? extends E> collection) Inserts the objects in the specified Collection at the specified location in this List.
void	clear() Removes all elements from this list, leaving it empty.
boolean	equals(Object object) Compares the specified object to this list and return true if they are equal.
abstract E	get(int location) Returns the element at the specified location in this list.
int	hashCode() Returns the hash code of this list.
int	indexOf(Object object) Searches this list for the specified object and returns the index of the first occurrence.
Iterator<E>	iterator() Returns an iterator on the elements of this list.
int	lastIndexOf(Object object) Searches this list for the specified object and returns the index of the last occurrence.
ListIterator<E>	listIterator() Returns a ListIterator on the elements of this list.
ListIterator<E>	listIterator(int location) Returns a list iterator on the elements of this list.
E	remove(int location) Removes the object at the specified location from this list.
E	set(int location, E object) Replaces the element at the specified location in this list with the specified object.
List<E>	subList(int start, int end) Returns a part of consecutive elements of this list as a view.

Protected Methods
void	removeRange(int start, int end) Removes the objects in the specified range from the start to the end index minus one.

[Expand]

Inherited Methods

From class java.util.AbstractCollection

boolean	add(E object) Attempts to add `object` to the contents of this `Collection` (optional).
boolean	addAll(Collection<? extends E> collection) Attempts to add all of the objects contained in `collection` to the contents of this `Collection` (optional).
void	clear() Removes all elements from this `Collection`, leaving it empty (optional).
boolean	contains(Object object) Tests whether this `Collection` contains the specified object.
boolean	containsAll(Collection<?> collection) Tests whether this `Collection` contains all objects contained in the specified `Collection`.
boolean	isEmpty() Returns if this `Collection` contains no elements.
abstract Iterator<E>	iterator() Returns an instance of Iterator that may be used to access the objects contained by this `Collection`.
boolean	remove(Object object) Removes one instance of the specified object from this `Collection` if one is contained (optional).
boolean	removeAll(Collection<?> collection) Removes all occurrences in this `Collection` of each object in the specified `Collection` (optional).
boolean	retainAll(Collection<?> collection) Removes all objects from this `Collection` that are not also found in the `Collection` passed (optional).
abstract int	size() Returns a count of how many objects this `Collection` contains.
<T> T[]	toArray(T[] contents) Returns an array containing all elements contained in this `Collection`.
Object[]	toArray() Returns a new array containing all elements contained in this `Collection`.
String	toString() Returns the string representation of this `Collection`.

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Is called before the object's memory is being reclaimed by the VM.
final Class<? extends Object>	getClass() Returns the unique instance of Class which represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.

From interface java.lang.Iterable

From interface java.util.Collection

abstract boolean	add(E object) Attempts to add `object` to the contents of this `Collection` (optional).
abstract boolean	addAll(Collection<? extends E> collection) Attempts to add all of the objects contained in `Collection` to the contents of this `Collection` (optional).
abstract void	clear() Removes all elements from this `Collection`, leaving it empty (optional).
abstract boolean	contains(Object object) Tests whether this `Collection` contains the specified object.
abstract boolean	containsAll(Collection<?> collection) Tests whether this `Collection` contains all objects contained in the specified `Collection`.
abstract boolean	equals(Object object) Compares the argument to the receiver, and returns true if they represent the same object using a class specific comparison.
abstract int	hashCode() Returns an integer hash code for the receiver.
abstract boolean	isEmpty() Returns if this `Collection` contains no elements.
abstract Iterator<E>	iterator() Returns an instance of Iterator that may be used to access the objects contained by this `Collection`.
abstract boolean	remove(Object object) Removes one instance of the specified object from this `Collection` if one is contained (optional).
abstract boolean	removeAll(Collection<?> collection) Removes all occurrences in this `Collection` of each object in the specified `Collection` (optional).
abstract boolean	retainAll(Collection<?> collection) Removes all objects from this `Collection` that are not also found in the `Collection` passed (optional).
abstract int	size() Returns a count of how many objects this `Collection` contains.
abstract <T> T[]	toArray(T[] array) Returns an array containing all elements contained in this `Collection`.
abstract Object[]	toArray() Returns a new array containing all elements contained in this `Collection`.

From interface java.util.List

abstract void	add(int location, E object) Inserts the specified object into this `List` at the specified location.
abstract boolean	add(E object) Adds the specified object at the end of this `List`.
abstract boolean	addAll(int location, Collection<? extends E> collection) Inserts the objects in the specified collection at the specified location in this `List`.
abstract boolean	addAll(Collection<? extends E> collection) Adds the objects in the specified collection to the end of this `List`.
abstract void	clear() Removes all elements from this `List`, leaving it empty.
abstract boolean	contains(Object object) Tests whether this `List` contains the specified object.
abstract boolean	containsAll(Collection<?> collection) Tests whether this `List` contains all objects contained in the specified collection.
abstract boolean	equals(Object object) Compares the given object with the `List`, and returns true if they represent the same object using a class specific comparison.
abstract E	get(int location) Returns the element at the specified location in this `List`.
abstract int	hashCode() Returns the hash code for this `List`.
abstract int	indexOf(Object object) Searches this `List` for the specified object and returns the index of the first occurrence.
abstract boolean	isEmpty() Returns whether this `List` contains no elements.
abstract Iterator<E>	iterator() Returns an iterator on the elements of this `List`.
abstract int	lastIndexOf(Object object) Searches this `List` for the specified object and returns the index of the last occurrence.
abstract ListIterator<E>	listIterator() Returns a `List` iterator on the elements of this `List`.
abstract ListIterator<E>	listIterator(int location) Returns a list iterator on the elements of this `List`.
abstract E	remove(int location) Removes the object at the specified location from this `List`.
abstract boolean	remove(Object object) Removes the first occurrence of the specified object from this `List`.
abstract boolean	removeAll(Collection<?> collection) Removes all occurrences in this `List` of each object in the specified collection.
abstract boolean	retainAll(Collection<?> collection) Removes all objects from this `List` that are not contained in the specified collection.
abstract E	set(int location, E object) Replaces the element at the specified location in this `List` with the specified object.
abstract int	size() Returns the number of elements in this `List`.
abstract List<E>	subList(int start, int end) Returns a `List` of the specified portion of this `List` from the given start index to the end index minus one.
abstract <T> T[]	toArray(T[] array) Returns an array containing all elements contained in this `List`.
abstract Object[]	toArray() Returns an array containing all elements contained in this `List`.

Fields

protected int modCount

A counter for changes to the list.

Protected Constructors

protected AbstractList ()

Constructs a new instance of this AbstractList.

Public Methods

public void add (int location, E object)

Inserts the specified object into this List at the specified location. The object is inserted before any previous element at the specified location. If the location is equal to the size of this List, the object is added at the end. Concrete implementations that would like to support the add functionality must override this method.

Parameters

location	the index at which to insert.
object	the object to add.

Throws

UnsupportedOperationException	if adding to this List is not supported.
ClassCastException	if the class of the object is inappropriate for this List
IllegalArgumentException	if the object cannot be added to this List
IndexOutOfBoundsException	if `location < 0 \|\| >= size()`

public boolean add (E object)

Adds the specified object at the end of this List.

Parameters

object	the object to add

Returns

true

Throws

UnsupportedOperationException	if adding to this List is not supported
ClassCastException	if the class of the object is inappropriate for this List
IllegalArgumentException	if the object cannot be added to this List

public boolean addAll (int location, Collection<? extends E> collection)

Inserts the objects in the specified Collection at the specified location in this List. The objects are added in the order they are returned from the collection's iterator.

Parameters

location	the index at which to insert.
collection	the Collection of objects

Returns

true if this List is modified, false otherwise.

Throws

UnsupportedOperationException	if adding to this list is not supported.
ClassCastException	if the class of an object is inappropriate for this list.
IllegalArgumentException	if an object cannot be added to this list.
IndexOutOfBoundsException	if `location < 0 \|\| > size()`

public void clear ()

Removes all elements from this list, leaving it empty.

Throws

UnsupportedOperationException	if removing from this list is not supported.

public boolean equals (Object object)

Compares the specified object to this list and return true if they are equal. Two lists are equal when they both contain the same objects in the same order.

Parameters

object	the object to compare to this object.

Returns

true if the specified object is equal to this list, false otherwise.

public abstract E get (int location)

Returns the element at the specified location in this list.

Parameters

location	the index of the element to return.

Returns

the element at the specified index.

Throws

IndexOutOfBoundsException	if `location < 0 \|\| >= size()`

public int hashCode ()

Returns the hash code of this list. The hash code is calculated by taking each element's hashcode into account.

Returns

the hash code.

public int indexOf (Object object)

Searches this list for the specified object and returns the index of the first occurrence.

Parameters

object	the object to search for.

Returns

the index of the first occurrence of the object, or -1 if it was not found.

public Iterator<E> iterator ()

Returns an iterator on the elements of this list. The elements are iterated in the same order as they occur in the list.

Returns

an iterator on the elements of this list.

public int lastIndexOf (Object object)

Searches this list for the specified object and returns the index of the last occurrence.

Parameters

object	the object to search for.

Returns

the index of the last occurrence of the object, or -1 if the object was not found.

public ListIterator<E> listIterator ()

Returns a ListIterator on the elements of this list. The elements are iterated in the same order that they occur in the list.

Returns

a ListIterator on the elements of this list

public ListIterator<E> listIterator (int location)

Returns a list iterator on the elements of this list. The elements are iterated in the same order as they occur in the list. The iteration starts at the specified location.

Parameters

location	the index at which to start the iteration.

Returns

a ListIterator on the elements of this list.

Throws

IndexOutOfBoundsException	if `location < 0 \|\| location > size()`

public E remove (int location)

Removes the object at the specified location from this list.

Parameters

location	the index of the object to remove.

Returns

the removed object.

Throws

UnsupportedOperationException	if removing from this list is not supported.
IndexOutOfBoundsException	if `location < 0 \|\| >= size()`

public E set (int location, E object)

Replaces the element at the specified location in this list with the specified object.

Parameters

location	the index at which to put the specified object.
object	the object to add.

Returns

the previous element at the index.

Throws

UnsupportedOperationException	if replacing elements in this list is not supported.
ClassCastException	if the class of an object is inappropriate for this list.
IllegalArgumentException	if an object cannot be added to this list.
IndexOutOfBoundsException	if `location < 0 \|\| >= size()`

public List<E> subList (int start, int end)

Returns a part of consecutive elements of this list as a view. The returned view will be of zero length if start equals end. Any change that occurs in the returned subList will be reflected to the original list, and vice-versa. All the supported optional operations by the original list will also be supported by this subList.

This method can be used as a handy method to do some operations on a sub range of the original list, for example list.subList(from, to).clear();

If the original list is modified in other ways than through the returned subList, the behavior of the returned subList becomes undefined.

The returned subList is a subclass of AbstractList. The subclass stores offset, size of itself, and modCount of the original list. If the original list implements RandomAccess interface, the returned subList also implements RandomAccess interface.

The subList's set(int, Object), get(int), add(int, Object), remove(int), addAll(int, Collection) and removeRange(int, int) methods first check the bounds, adjust offsets and then call the corresponding methods of the original AbstractList. addAll(Collection c) method of the returned subList calls the original addAll(offset + size, c).

The listIterator(int) method of the subList wraps the original list iterator. The iterator() method of the subList invokes the original listIterator() method, and the size() method merely returns the size of the subList.

All methods will throw a ConcurrentModificationException if the modCount of the original list is not equal to the expected value.

Parameters

start	start index of the subList (inclusive).
end	end index of the subList, (exclusive).

Returns

a subList view of this list starting from start (inclusive), and ending with end (exclusive)

Throws

IndexOutOfBoundsException	if (start < 0 \|\| end > size())
IllegalArgumentException	if (start > end)

Protected Methods

protected void removeRange (int start, int end)

Removes the objects in the specified range from the start to the end index minus one.

Parameters

start	the index at which to start removing.
end	the index after the last element to remove.

Throws

UnsupportedOperationException	if removing from this list is not supported.
IndexOutOfBoundsException	if `start < 0` or `start >= size()`.

Interfaces

Classes

Enums

Exceptions

AbstractList

Class Overview

Summary

Fields

protected int modCount

Protected Constructors

protected AbstractList ()

Public Methods

public void add (int location, E object)

Parameters

Throws

public boolean add (E object)

Parameters

Returns

Throws

public boolean addAll (int location, Collection<? extends E> collection)

Parameters

Returns

Throws

public void clear ()

Throws

See Also

public boolean equals (Object object)

Parameters

Returns

See Also

public abstract E get (int location)

Parameters

Returns

Throws

public int hashCode ()

Returns

See Also

public int indexOf (Object object)

Parameters

Returns

public Iterator<E> iterator ()

Returns

See Also

public int lastIndexOf (Object object)

Parameters

Returns

public ListIterator<E> listIterator ()

Returns

See Also

public ListIterator<E> listIterator (int location)

Parameters

Returns

Throws

See Also

public E remove (int location)

Parameters

Returns

Throws

public E set (int location, E object)

Parameters

Returns

Throws

public List<E> subList (int start, int end)

Parameters

Returns

Throws

Protected Methods

protected void removeRange (int start, int end)

Parameters

Throws