AbstractLinkedList (Apache Commons Collections 3.2.2 API)

java.lang.Object
- org.apache.commons.collections.list.AbstractLinkedList

All Implemented Interfaces:

Iterable, Collection, List

Direct Known Subclasses:

CursorableLinkedList, NodeCachingLinkedList
```
public abstract class AbstractLinkedList
extends Object
implements List
```
An abstract implementation of a linked list which provides numerous points for subclasses to override.
Overridable methods are provided to change the storage node and to change how nodes are added to and removed. Hopefully, all you need for unusual subclasses is here.

Since:

Commons Collections 3.0

Version:

$Revision: 972404 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $

Author:

Rich Dougherty, Phil Steitz, Stephen Colebourne

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`protected static class`	`AbstractLinkedList.LinkedListIterator` A list iterator over the linked list.
`protected static class`	`AbstractLinkedList.LinkedSubList` The sublist implementation for AbstractLinkedList.
`protected static class`	`AbstractLinkedList.LinkedSubListIterator` A list iterator over the linked sub list.
`protected static class`	`AbstractLinkedList.Node` A node within the linked list.

Field Summary

Fields
Modifier and Type	Field and Description
`protected AbstractLinkedList.Node`	`header` A `AbstractLinkedList.Node` which indicates the start and end of the list and does not hold a value.
`protected int`	`modCount` Modification count for iterators
`protected int`	`size` The size of the list

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`AbstractLinkedList()` Constructor that does nothing intended for deserialization.
`protected`	`AbstractLinkedList(Collection coll)` Constructs a list copying data from the specified collection.

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`add(int index, Object value)`
`boolean`	`add(Object value)`
`boolean`	`addAll(Collection coll)`
`boolean`	`addAll(int index, Collection coll)`
`boolean`	`addFirst(Object o)`
`boolean`	`addLast(Object o)`
`protected void`	`addNode(AbstractLinkedList.Node nodeToInsert, AbstractLinkedList.Node insertBeforeNode)` Inserts a new node into the list.
`protected void`	`addNodeAfter(AbstractLinkedList.Node node, Object value)` Creates a new node with the specified object as its `value` and inserts it after `node`.
`protected void`	`addNodeBefore(AbstractLinkedList.Node node, Object value)` Creates a new node with the specified object as its `value` and inserts it before `node`.
`void`	`clear()`
`boolean`	`contains(Object value)`
`boolean`	`containsAll(Collection coll)`
`protected AbstractLinkedList.Node`	`createHeaderNode()` Creates a new node with previous, next and element all set to null.
`protected AbstractLinkedList.Node`	`createNode(Object value)` Creates a new node with the specified properties.
`protected Iterator`	`createSubListIterator(AbstractLinkedList.LinkedSubList subList)` Creates an iterator for the sublist.
`protected ListIterator`	`createSubListListIterator(AbstractLinkedList.LinkedSubList subList, int fromIndex)` Creates a list iterator for the sublist.
`protected void`	`doReadObject(ObjectInputStream inputStream)` Deserializes the data held in this object to the stream specified.
`protected void`	`doWriteObject(ObjectOutputStream outputStream)` Serializes the data held in this object to the stream specified.
`boolean`	`equals(Object obj)`
`Object`	`get(int index)`
`Object`	`getFirst()`
`Object`	`getLast()`
`protected AbstractLinkedList.Node`	`getNode(int index, boolean endMarkerAllowed)` Gets the node at a particular index.
`int`	`hashCode()`
`int`	`indexOf(Object value)`
`protected void`	`init()` The equivalent of a default constructor, broken out so it can be called by any constructor and by `readObject`.
`boolean`	`isEmpty()`
`protected boolean`	`isEqualValue(Object value1, Object value2)` Compares two values for equals.
`Iterator`	`iterator()`
`int`	`lastIndexOf(Object value)`
`ListIterator`	`listIterator()`
`ListIterator`	`listIterator(int fromIndex)`
`Object`	`remove(int index)`
`boolean`	`remove(Object value)`
`boolean`	`removeAll(Collection coll)`
`protected void`	`removeAllNodes()` Removes all nodes by resetting the circular list marker.
`Object`	`removeFirst()`
`Object`	`removeLast()`
`protected void`	`removeNode(AbstractLinkedList.Node node)` Removes the specified node from the list.
`boolean`	`retainAll(Collection coll)`
`Object`	`set(int index, Object value)`
`int`	`size()`
`List`	`subList(int fromIndexInclusive, int toIndexExclusive)` Gets a sublist of the main list.
`Object[]`	`toArray()`
`Object[]`	`toArray(Object[] array)`
`String`	`toString()`
`protected void`	`updateNode(AbstractLinkedList.Node node, Object value)` Updates the node with a new value.

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - header
```
protected transient AbstractLinkedList.Node header
```
    A AbstractLinkedList.Node which indicates the start and end of the list and does not hold a value. The value of next is the first item in the list. The value of of previous is the last item in the list.
  - size
```
protected transient int size
```
    The size of the list
  - modCount
```
protected transient int modCount
```
    Modification count for iterators
- Constructor Detail
  - AbstractLinkedList
```
protected AbstractLinkedList()
```
    Constructor that does nothing intended for deserialization.
    If this constructor is used by a serializable subclass then the init() method must be called.
  - AbstractLinkedList
```
protected AbstractLinkedList(Collection coll)
```
    Constructs a list copying data from the specified collection.
    
    Parameters:
    coll - the collection to copy
- Method Detail
  - init
```
protected void init()
```
    The equivalent of a default constructor, broken out so it can be called by any constructor and by readObject. Subclasses which override this method should make sure they call super, so the list is initialised properly.
  - size
```
public int size()
```
    Specified by:
    
    size in interface Collection
    
    Specified by:
    
    size in interface List
  - isEmpty
```
public boolean isEmpty()
```
    Specified by:
    
    isEmpty in interface Collection
    
    Specified by:
    
    isEmpty in interface List
  - get
```
public Object get(int index)
```
    Specified by:
    
    get in interface List
  - iterator
```
public Iterator iterator()
```
    Specified by:
    
    iterator in interface Iterable
    
    Specified by:
    
    iterator in interface Collection
    
    Specified by:
    
    iterator in interface List
  - listIterator
```
public ListIterator listIterator()
```
    Specified by:
    
    listIterator in interface List
  - listIterator
```
public ListIterator listIterator(int fromIndex)
```
    Specified by:
    
    listIterator in interface List
  - indexOf
```
public int indexOf(Object value)
```
    Specified by:
    
    indexOf in interface List
  - lastIndexOf
```
public int lastIndexOf(Object value)
```
    Specified by:
    
    lastIndexOf in interface List
  - contains
```
public boolean contains(Object value)
```
    Specified by:
    
    contains in interface Collection
    
    Specified by:
    
    contains in interface List
  - containsAll
```
public boolean containsAll(Collection coll)
```
    Specified by:
    
    containsAll in interface Collection
    
    Specified by:
    
    containsAll in interface List
  - toArray
```
public Object[] toArray()
```
    Specified by:
    
    toArray in interface Collection
    
    Specified by:
    
    toArray in interface List
  - toArray
```
public Object[] toArray(Object[] array)
```
    Specified by:
    
    toArray in interface Collection
    
    Specified by:
    
    toArray in interface List
  - subList
```
public List subList(int fromIndexInclusive,
           int toIndexExclusive)
```
    Gets a sublist of the main list.
    
    Specified by:
    
    subList in interface List
    
    Parameters:
    fromIndexInclusive - the index to start from
    toIndexExclusive - the index to end at
    
    Returns:
    the new sublist
  - add
```
public boolean add(Object value)
```
    Specified by:
    
    add in interface Collection
    
    Specified by:
    
    add in interface List
  - add
```
public void add(int index,
       Object value)
```
    Specified by:
    
    add in interface List
  - addAll
```
public boolean addAll(Collection coll)
```
    Specified by:
    
    addAll in interface Collection
    
    Specified by:
    
    addAll in interface List
  - addAll
```
public boolean addAll(int index,
             Collection coll)
```
    Specified by:
    
    addAll in interface List
  - remove
```
public Object remove(int index)
```
    Specified by:
    
    remove in interface List
  - remove
```
public boolean remove(Object value)
```
    Specified by:
    
    remove in interface Collection
    
    Specified by:
    
    remove in interface List
  - removeAll
```
public boolean removeAll(Collection coll)
```
    Specified by:
    
    removeAll in interface Collection
    
    Specified by:
    
    removeAll in interface List
  - retainAll
```
public boolean retainAll(Collection coll)
```
    Specified by:
    
    retainAll in interface Collection
    
    Specified by:
    
    retainAll in interface List
  - set
```
public Object set(int index,
         Object value)
```
    Specified by:
    
    set in interface List
  - clear
```
public void clear()
```
    Specified by:
    
    clear in interface Collection
    
    Specified by:
    
    clear in interface List
  - getFirst
```
public Object getFirst()
```
  - getLast
```
public Object getLast()
```
  - addFirst
```
public boolean addFirst(Object o)
```
  - addLast
```
public boolean addLast(Object o)
```
  - removeFirst
```
public Object removeFirst()
```
  - removeLast
```
public Object removeLast()
```
  - equals
```
public boolean equals(Object obj)
```
    Specified by:
    
    equals in interface Collection
    
    Specified by:
    
    equals in interface List
    
    Overrides:
    
    equals in class Object
  - hashCode
```
public int hashCode()
```
    Specified by:
    
    hashCode in interface Collection
    
    Specified by:
    
    hashCode in interface List
    
    Overrides:
    
    hashCode in class Object
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object
  - isEqualValue
```
protected boolean isEqualValue(Object value1,
                   Object value2)
```
    Compares two values for equals. This implementation uses the equals method. Subclasses can override this to match differently.
    
    Parameters:
    value1 - the first value to compare, may be null
    value2 - the second value to compare, may be null
    
    Returns:
    true if equal
  - updateNode
```
protected void updateNode(AbstractLinkedList.Node node,
              Object value)
```
    Updates the node with a new value. This implementation sets the value on the node. Subclasses can override this to record the change.
    
    Parameters:
    node - node to update
    value - new value of the node
  - createHeaderNode
```
protected AbstractLinkedList.Node createHeaderNode()
```
    Creates a new node with previous, next and element all set to null. This implementation creates a new empty Node. Subclasses can override this to create a different class.
    
    Returns:
    newly created node
  - createNode
```
protected AbstractLinkedList.Node createNode(Object value)
```
    Creates a new node with the specified properties. This implementation creates a new Node with data. Subclasses can override this to create a different class.
    
    Parameters:
    value - value of the new node
  - addNodeBefore
```
protected void addNodeBefore(AbstractLinkedList.Node node,
                 Object value)
```
    Creates a new node with the specified object as its value and inserts it before node.
    This implementation uses createNode(Object) and addNode(AbstractLinkedList.Node,AbstractLinkedList.Node).
    
    Parameters:
    node - node to insert before
    value - value of the newly added node
    
    Throws:
    
    NullPointerException - if node is null
  - addNodeAfter
```
protected void addNodeAfter(AbstractLinkedList.Node node,
                Object value)
```
    Creates a new node with the specified object as its value and inserts it after node.
    This implementation uses createNode(Object) and addNode(AbstractLinkedList.Node,AbstractLinkedList.Node).
    
    Parameters:
    node - node to insert after
    value - value of the newly added node
    
    Throws:
    
    NullPointerException - if node is null
  - addNode
```
protected void addNode(AbstractLinkedList.Node nodeToInsert,
           AbstractLinkedList.Node insertBeforeNode)
```
    Inserts a new node into the list.
    
    Parameters:
    nodeToInsert - new node to insert
    insertBeforeNode - node to insert before
    
    Throws:
    
    NullPointerException - if either node is null
  - removeNode
```
protected void removeNode(AbstractLinkedList.Node node)
```
    Removes the specified node from the list.
    
    Parameters:
    node - the node to remove
    
    Throws:
    
    NullPointerException - if node is null
  - removeAllNodes
```
protected void removeAllNodes()
```
    Removes all nodes by resetting the circular list marker.
  - getNode
```
protected AbstractLinkedList.Node getNode(int index,
                              boolean endMarkerAllowed)
                                   throws IndexOutOfBoundsException
```
    Gets the node at a particular index.
    
    Parameters:
    index - the index, starting from 0
    endMarkerAllowed - whether or not the end marker can be returned if startIndex is set to the list's size
    
    Throws:
    
    IndexOutOfBoundsException - if the index is less than 0; equal to the size of the list and endMakerAllowed is false; or greater than the size of the list
  - createSubListIterator
```
protected Iterator createSubListIterator(AbstractLinkedList.LinkedSubList subList)
```
    Creates an iterator for the sublist.
    
    Parameters:
    subList - the sublist to get an iterator for
  - createSubListListIterator
```
protected ListIterator createSubListListIterator(AbstractLinkedList.LinkedSubList subList,
                                     int fromIndex)
```
    Creates a list iterator for the sublist.
    
    Parameters:
    subList - the sublist to get an iterator for
    fromIndex - the index to start from, relative to the sublist
  - doWriteObject
```
protected void doWriteObject(ObjectOutputStream outputStream)
                      throws IOException
```
    Serializes the data held in this object to the stream specified.
    The first serializable subclass must call this method from writeObject.
    
    Throws:
    
    IOException
  - doReadObject
```
protected void doReadObject(ObjectInputStream inputStream)
                     throws IOException,
                            ClassNotFoundException
```
    Deserializes the data held in this object to the stream specified.
    The first serializable subclass must call this method from readObject.
    
    Throws:
    
    IOException
    
    ClassNotFoundException

Class AbstractLinkedList

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

header

size

modCount

Constructor Detail

AbstractLinkedList

AbstractLinkedList

Method Detail

init

size

isEmpty

get

iterator

listIterator

listIterator

indexOf

lastIndexOf

contains

containsAll

toArray

toArray

subList

add

add

addAll

addAll

remove

remove

removeAll

retainAll

set

clear

getFirst

getLast

addFirst

addLast

removeFirst

removeLast

equals

hashCode

toString

isEqualValue

updateNode

createHeaderNode

createNode

addNodeBefore

addNodeAfter

addNode

removeNode

removeAllNodes

getNode

createSubListIterator

createSubListListIterator

doWriteObject

doReadObject